Well I just went out and did a test....with everything hooked up (air cleaner on, etc.), and was spraying starter fluid on vacuum lines and stuff, around the EVAP cannister, I didn't get any RPM jumps. Right directly on top of the PCV valve where it plus into the snorkel, I got a very slight increase (I don't have any rubber grommet on the end of the PCV valve going into the snorkel - is there supposed to be one?) When I sprayed around the whole perimeter of the top lid of the air cleaner, the RPM increased around that whole perimeter (which suggests a non-airtight seal of the lid??). Lastly, I tried to spray directly behind the water pump where the intake manifold sits directly on top of the block and RPMs went up (which suggests a bad manifold gasket?).

 

Base idle before spraying any fluid was 15-16 RPMS; in the areas that the spray affected, it never got above 18. So, it's like a 200-300 RPM increase. It always dropped back down to the 1500-1600 after it burned off the spray.

 

Sounds like there is an issue there for sure. You can also try along the sides of the intake manifold to see if its in multiple places.

 

Yes, that's what it looks like it's pointing to. I found a new intake manifold gasket in the garage that my father had bought (he has since passed away, 9 years ago now) - he probably knew it was going bad. He was an excellent ASE Certified Mechanic and I swear he could fix anything. Sure could use his help now! lol

 

Found the EST. Going to unplug it and set base timing 0 -4

 

These pics show what I did. I hooked up my timing light and hooked up the clamp around #1 spark plug wire, unhooked the EST, started the car, used the timing light to see where the notch was. Turned off the car. Plugged in the EST again, started the car, and saw that the notch was in the exact same spot. Is the notch supposed to be in a different spot with the EST plugged in vs. not plugged in? And if so, by how much, because mine didn't move at all; does it take the engine a while to register where the notch is supposed to be? Because I only let the engine run about a minute in both scenarios. If the notch is supposed to be in a different spot when the EST is plugged in vs. non plugged in, and mine didn't move at all, what does that mean?

See attached pics to confirm that this is the EST that I was supposed to unplug and re-plug in. (I just borrowed that picture of the notches for the timing from another post on here, and edited it to show you the green mark where mine lines up. I also don't have any numbers or degrees on mine, just like in the picture, but as far as I know, zero degrees is all the way to the edge of the right of the big V. Or....is zero degrees right in the middle of the big V notch?)




Also, does anybody know what this connector is that is sticking out of the lume for the wiring harness?

 

I've got a base model late production 1992 Pontiac Firebird that has every option you could possibly get on a base model Firebird except for the U1A CD Player. The car is 100% unmolested bone stock original as it left the factory except for normal consumable wear items. There are several unused connectors under hood and throughout the car that don't go to anything.

Right offhand I don't know what that connector goes to if it goes to anything.

 

The connector you have labeled EST is correct. Unplug it, start the car and set the idle. The timing points are 1 degree increments between peak and valley. Paint a white line on the balancer mark and sand off the surface rust on the pointer to see the numbers. Basically if your timing is somewhere in the middle there with the EST disconnected at idle, you're good. I have a feeling you're going to have an intake manifold removal project soon.

 

so what does it mean if the timing didn't change at all with or without the EST bypass being plugged in or not. I checked the timing both with it plugged in and not plugged in and it was the exact same. I did a quick research and that may suggest that because the timing doesn't change at all whether or not the EST bypass is hooked up or not then the ECU isn't doing it's job and regulating the timing when the bypass is hooked up. From what I read and understand is that when you unplug the EST bypass you are taking the ECU out of the equation and just relying on the distributor to do the time hence "base timing" and then when you plug the EST bypass back in then the ECU takes over and adjusts, retards or advances the timing based off the starting point "base time" that you set it to when the bypass was unplugged.

My issue is the timing doesn't change at all with or without the bypass being plugged in or not...so my ECU isn't doing it's job? not getting signal from the EST circitry, bad prom? bad ecu? remember my brother said he replaced the ecu a few years ago. so this isn't the stock original ecu that came with this car, but the old prom from the old ecu is in the new ecu, a hypertech prom. my service engine light soon is on steady, and remains steady, I can't get it to go into diagnostic mode when I jump terminals A and B on the ALDL, and I'm pretty sure I'm making good contact on the metal pins on the ALDL...again I read that could be a bad prom or ecu...

What do you guys think?

Last night I went and rechecked all the vaccume lines that I could think of, PCV valve, lines going to the cannister, to the IAT sensor inside the air cleaner, going to the EGR valve, the the line in the back of the throttle body, etc...I found a small piece of bare wire going into a connector where one of the vac lines was going to a connector that hooked up to something, may have been a EGR solenoid not sure, anyway I fixed that and it didn't change anything. When tracing vac lines I found two smaller diameter vac lines that eventually went into some lume and I think back into the fire wall maybe? I don't think those are messed up. The metal hose/pipe that I think is my crank case breather hose going into the air cleaner housing is really easy to move around and a bit wobbly when disconnected from the short rubber hose attaching it to the crank case breather element assembly nozzle sticking out of the air cleaner housing...and the point where the little filter assembly fits through the square hole in the aircleaner housing isn't the tightest of situations... could this be a problem?

could my EST control module be bad? also I double checked to make sure all spark plugs wires are routing back to the correct post on the distributor, because my brother said he changed the cap, not sure about the rotor inside.

 

I've been out of the TBI game for too long to remember what the timing looks like with the EST plugged. My memory tells me it shows an advance. None the less, timing won't cause an increase an RPM's. Airflow does. You're doing all the right things but I think the intake manifold has to come off. Did you spray around all the intake ports to see if it is worse in some areas? If so, intake has to come off.

 

Quick Update:

I checked the timing with the EST bypass plugged in and gave it some throttle and noticed that when I did that, the notch did advance some going towards zero. Then it went back to where it was when I let off the throttle. So, do I take it that the ECU is, in fact, working with the timing? Whereas before I said it probably wasn't (but I had never given it throttle before, and watched)?

Also, I want to do a smoke leak test. Where should I plug the vacuum line up to put smoke intake?

 

ok so I did a homemade smoke leak detector test with a pump, rubber glove and some tape, and a black and mild cigar.

I hooked the tube up to a finger on the rubber glove and taped it so it had a good seal, then wrapped the glove around the entrance to the intake and taped it so it had a good seal, then pumped in smoke via the pump and cigar.

I also put the throttle lever to where the butterflys were open a bit in the throttle body, so the smoke could go down and into the intake manifold and fill it and any other vac lines in the system.

I started pumping the smoke and immediately saw smoke coming from the areas shown in the picture. Out the bottom side of the vac motor or thermac I think it's called, the round thing hooked up to the snorkel and has a flap mechanism on the inside.

then I saw smoke coming from the connection point of the crank case breather tube and the crankcase breather element that is house inside the air cleaner and has a short snorkel piece that comes out a square hold in the side of the air cleaner to attach to the crank case breather tube.

then I saw smoke coming from the top edges of the top of my air filter housing, like my lid didn't have a good seal or something, but I had it tightened down pretty good. I tried removing the actual kn air filter from the housing and put the top back on and there was less smoke, but still some. That kinda sounds like this filter might not be letting the lid close all the way? but like I said even with the filter completely out, it still leaked some smoke from out the edges.

BUT I didn't see smoke coming from any vacc lines, or intake manifold gasket areas.... suggesting I don't have a vacc leak there... Would the smoke I saw coming from the areas I saw be enough of a leak to cause my high idle of 1700 rpms? and 1200 rpms in drive or reverse?

Also correct me if I'm wrong but should this air cleaner housing be sitting like level, see how it's kicked to one side a bit? That's tightened down too... what in the hell would cause that, or is that normal for it to look like that?

 

Man I thought someone would answer you earlier question about where to apply the smoke. My bad.

Take the entire air cleaner assembly off the car and disconnect the vacuum hose/s from the throttle body that go to the air cleaner assembly. Use rubber plugs and plug off any of the vacuum ports on the throttle body that you disconnected the vacuum hose/s from.

Trace the rubber hose going to the vacuum brake booster back to the throttle body and blow your smoke in from there.

Air / Vacuum leaks that matter enough to make your engine run like azz are below the throttle blades of the throttle body.

On top of the throttle body casting goes a big round about 5.25" gasket, them a stamped sheet metal spacer, then another one of those big round gaskets then the air cleaner base sits on that. I think all these things are notched and indexed to fit a certain way.

 

The two areas you are seeing smoke are "outside" of the engine air metering and won't effect RPM. The air cleaner won't be surgically sealed as its not gasketed. You could now try external smoke and see if any is being sucked in along the sides of the intake manifold.

 

Ok, so here are a few images of the air box assembly and crankcase breather hose, and brake booster hose and hardline.

So, for the smoke test, do I have this right? unhook that rubber hose from the brake booster and put smoke straight into the rubber hose end? Also what's that little valve thing attached to the other side of that hose, and I guess that's a hard metal vacuum line after that valve going into the intake?

for the crankcase breather hose, see images. do I have the tension clip on right, my car didn't have one when I started working on it and it was always loose as hell. it's a little bit better now with this clip and new filter.
as far as the metal breather hose, is it supposed to be that loose or easy to move?

I still can't figure out why my air box looks canted or at an angle when tightened down.... I don't see anything that would make it do that if my post is in the middle of the TB and it tightens down, I would think it would tighten down from the center and make it flush and level when tight?

in the images are the notches/cut out tabs that I saw that I guess help these things line up correctly ontop of the TB...I have this correct right? also notice the slightly bent tab on the metal cylindrical flange that sits on top of the TB.. I don't think this would be much of an issue, but am I wrong.

Also to note, these paper thin type gaskets, one on the bottom of the air cleaner and one on top, When I removed the old gasket, there was only 1 gasket on the bottom and it was about 1/8 thick, where as these are like 1/16'' thick, I never had one on top when I started working on this car, but put the new paper gasket on top because I think it was supposed to be there.

ok please answer these questions so I can move forward, and thanks guys for all the help! Also is there no way I can rename this thread title to like HIGH IDLE 1700RPM 92 camaro 305 5.0L automatic. I don't want people thinking this thread is about my fuel pump anymore, I believe that issue solved

In the picture here, I think I have the EGR valve shown in that the gasket looks really rough, but I don't think it's leaking. Could this be a problem? Is there a way to test the EGR valve to see if it's working or not? Should I just go ahead and replace the valve and gasket?

Also, if I wanted to try a different EPROM, does anyone have a good recommendation where I can get a good one that will also work with the current ECU that I have in there now, which can be seen in the pictures in previous posts here, for the GM number, service number, etc.

 

I was up all night binge watching a TV show. I just got up about Noon.

Let me get some Cherry RC in me and smoke a few cigarettes then I'll go outside and take some pictures of my 92 TBI Firebird under hood. I'll murder nuns and stomp kittens when I first get up until I get some caffeine and nicotine in me.

 

I WILL BE EDITING MY REPLY AS I GO. SO REFRESH THIS PAGE TO SEE UPDATES TO THIS REPLY.

To edit the title of your thread go to your very first post at the top of this thread and click on EDIT, then click on Go Advanced, then in the edit box you will see where you can change the title of your post, change it to whatever you want then click on SAVE CHANGES.

See example of how I edited the title of this reply to you thread at the top of this reply.

The metal tension clip is installed backwards. Flip it around so the little 90 degree bend is facing away from the air cleaner housing. This makes it easier to grip when sliding it off in the future.

No the metal Crank Case Ventilation tube that goes into the passenger side valve cover is not supposed to flop around like a hotdog down a hallway. The rubber grommet in the valve cover needs to be replaced. The Positive Crankcase Ventilation valve in the driver side valve cover is also not supposed to flop around in the grommet like a hotdog down a hallway. The short rubber hose from the CCV metal tube to the little air filer assembly in the air cleaner housing base should fit tightly as should the rubber hose going to the PCV valve.

Like I mentioned earlier and like @ShiftyCapone just mentioned you can leak all the air you want above the throttle blades in the throttle body on the air intake side of things. It's only air / vacuum leaks below the throttle blades in the throttle body that matter.

Don't bother with replacing the valve cover grommets now. You will be replacing them when you install new valve cover gaskets while you have the intake manifold off to install new intake manifold gaskets and reseal the front and back China wall to fix your vacuum leak. Those rubber grommets will be hard as a rock and will crumble and break apart and fall into the head while you are trying to remove them.

On the hard metal vacuum line going from the intake manifold to the vacuum brake booster is a Power Brake Filter and a Power Brake Check Valve and rubber grommet with rubber vacuum hoses in between. Disconnect the rubber vacuum hose from the metal vacuum line before the black Power Brake Filter and connect your smoke machine there to the metal vacuum line and feed the smoke into your intake manifold from there.

As to your air cleaner sitting crooked on your throttle body. Is it possible your air cleaner is sitting correctly on top your throttle body and your engine is sitting crooked in your car? They ain't too many ways to put your air cleaner on crooked so it ain't sitting right that don't just jump right out at you and stick out like a sore thumb.

 

The only gasket that matters on the air cleaner/TBI unit is the one that touches the intake manifold. Any air that being sucked into the top of the TBI, even if it is through minor gaps, is not going to affect idle. That air will be metered. Its any air that gets in that doesn't go through the TBI unit that's the problem. The passenger side crankcase vent also doesn't have to be sealed as its not on the induction side of the engine. A stuck EGR valve I suppose could increase your idle, I think. You may want to unplug it and put your finger over the hole and see what the motor does.

 

If there is a rubber grommet at the base of the CCV metal tube, it's so hard that it feels like metal or plastic now. I can basically turn the metal tube 360 degrees pretty easily. The short little rubber hose connecting the CCV to the air cleaner (snorkel) tube is also kind of loose and smoke was coming out of that too. So, I guess i need to replace that short little rubber tube and maybe look for another rubber grommet for the base of the metal tube? I'll also try flipping that clip around. Also, it looks like the PCV valve grommet looks like it's metal but again, maybe it's so dried up it looked that hard - actually looks like it's part of the cover!

I'll try to unplug the vacuum line going to the EGR valve and close the vacuum line with my thumb? Or, am I putting my thumb over the EGR valve vacuum line port hole?

That's what I thought about the TB gaskets, and as far as I can tell, the gasket that makes contact with the top of the intake manifold has no leaks. I did another starter fluid spray test to check for leaks today, and they only areas that the RPMs changed were when I sprayed directly on the PCV valve port going into the snorkel - a change of about 100-200 RPMs increase, which you say won't cause a high idle anyway. When I sprayed on top of the EVAP cannister, again, 100-200 RPM increase, but that may be because there's actually an open vent port that I think is supposed to be open, so it may have been sucking it in through there. At the very front of the intake manifold, where you normally use RTV to seal it, I saw the biggest increase - probably 100-300 RPMs, so I might have a small leak right there at the front of the manifold where the RTV may be failing, but it wasn't a huge jump in RPMs. My question is, if that's basically where it's failing on the intake manifold, and it's already RTV, can I slather some more RTV on top of what's already there and maybe seal the leak? Because I don't think it's the gasket that's failing - I think its the RTV. I sprayed on both sides of the intake manifold and saw no change in RPMs, and all the vacuum lines I can think of or see.

I read something somewhere where it said there could be an "internal" vacuum leak of the intake manifold, and not on the actual perimeter of the gasket of the intake manifold - does this sound right?

If you refer back to the picture where I showed my base timing, does that look right? Because it's not at 0. Also my fans kicked on at about 230 degrees so that's normal - everything is running at within normal temperature ranges.

 

Also, while I was test driving just now, without even touching the gas, when I let my foot off the brake, the car starts rolling and will eventually go into 2nd gear, and if I let it keep going, it will probably reach 30-35 MPH without ever touching the gas. The base idle while in drive and reverse, is 1200 RPMs. So, yeah....high idle. As soon as I put it in park or neutral it goes back to 1700-1800 RPMS.

 

We got the back half of your car's problem fixed, the fuel pump issue is taken care of for now and fingers crossed it stays fixed for a good long while.

Now we are working on the front half of the car with the high idle issue. It's a vacuum leak, most likely. We are going to laser focus on that issue for now. Base timing, ECMs and chips, CCV & PCV, and air cleaner housing and related stuff, that's not the problem. At best those are sweet sprinkles on top of a frosting covered cupcake.

I got back from my errands and started taking pictures under hood of my car to show you things and found the source of my little intermittent miss. It's a problem I've fixed before when I first got my car. Now it's a problem again. F*cking Dorman junk. The rubber vacuum nipple on the back of the throttle body that connects the hard plastic vacuum line going to my MAP sensor has failed. All cracked up and dry rotted. That Dorman rubber nipple been on there 3 years and I ain't driven it 700 miles and it's 100% crumbled, cracked, split, rotten junk.

It's ate up like that all the way around and on the left end of it was a tapered nipple an inch long.


Trying to help you with your problem I have found mine. LoL

It's 92 degrees Fahrenheit and 92% humidity and I'm sweating ***** and my brain is boiling inside my skull.

 

On the metal vacuum line going to the brake booster right below the black Power Brake Filter disconnect the rubber hose from the metal vacuum line and connect your smoke machine to the metal vacuum line and pour the coals to it with the smoke. There is a metal spring clip you will have to squeeze together with some pliers and slid it up the rubber hose as far as you can, then twist the rubber hose off the metal vacuum line.

 

This is unrelated to your high idle problem but I will answer the questions.


The air cleaner wingnut is not installed in this picture so my air cleaner assembly is drooping toward the driver side just the slightest bit.



Make sure everything is properly aligned and indexed. Notice the notches on the throttle body spacer and the inside of the air cleaner base.



If your spacer gaskets and spacer are properly installed and indexed, and your air cleaner base is properly installed and indexed, lid installed and tightened just snug then it should look like mine does. You could have bad, the wrong, or incorrectly installed motor mounts if your air cleaner assembly is installed correctly.


These orange and red wires with connectors don't go to anything on my 1992 Firebird.

The metal spring clip that retains the little air cleaner assembly for the CCV system is installed like shown in this picture.

 

Ok, I'll try to focus more on the vacuum leak. I just ordered a proper smoke machine instead of the homemade "Black and Mild" and rubber glove method - it will be here tomorrow.

Glad you found your broken elbow. Crazy it only lasted that long! Mine (original) seems to be fine.

I flipped the retainer clip for the CCV filter around and it is a much better fit and a lot tighter now. I see how that works! lol

I may end up ordering an IAT sensor that goes inside the air cleaner housing for like $19, so I might as well try it.

 

No need to go ***** nilly replacing parts that aren't proven to be bad. The $19.00 that you might not need to spend can go toward the parts that you will need to actually fix your problem.

When I got my car it ran rough. I connected it to my Snap-on MT-2500 "Red Brick" and it told me something was wrong with the MAP system. I then noticed the black GM MAP sensor had been replaced with a aftermarket grey MAP sensor. I visually inspected the MAP system and found that a mouse had chewed up my rubber nipple and hard plastic vacuum line right at the back of the throttle body.

I bought a Dorman hard plastic line kit and rubber nipple kit and heated and hand formed a new line to match the factory GM hard vacuum line and selected the correct size rubber nipple out of the kit to replace the factory GM rubber nipple. I then raided my known good factory GM spare parts bin and put a Genuine GM MAP sensor on the car.

I would have paid anything to to put a brand new Genuine GM vacuum line assembly on the car instead but couldn't find one anywhere to buy. I'm going to hunt me down a nice used factory GM one if I can.

You asked about the running temperature earlier. My car in today's heat, at idle, in PARK, with the hood closed runs in the 220F to 230F range with the cooling fan cycling on around 226F

 

Thanks so much for posting those pics and for answering my questions. I think I might have had something misaligned when I posted the last pic of the air cleaner because today when I took it off and put it back on, I paid special attention of how it was sitting and now it's semi straight - still leaning a tiny bit but nowhere near as bad as it was. Thanks for confirming that those orange and red connectors are unplugged via the factory.

 

Understood. I saw a video on how to test an IAT sensor by using a volt/ohm meter and a hairdryer (or heat gun), and it basically showed that when heat was applied the OHMs dropped. If it doesn't drop it suggests a bad or faulty sensor, so I guess I could try that test before I buy a new one.

 

Well it's not so hot outside right now like it was earlier. I'm going to run down to my shop and get that Dorman kit of rubber nipples and replace my rotten one and see how she runs.

I edited some of my replies above to add additional information.

I have more pictures to add later on showing how to test the vacuum diaphragm in the air cleaner snorkel flapper valve and the EGR valve.

 

The IAT won't cause high idle. You're getting close and your perseverance is solid which is what it takes. Keep looking at everything. When you do the carb spray test, only do it south of the TBI unit or you may get most or fumes that give you a false positive. Focus on the front and sides of the intake manifold for "Internal" leaks and hook your eyes on all the vacuum connectors coming from the TBI. You're close.

 

Well I got my rough idle and miss fixed. Running like a champ again.

Hope you have as much luck and it's as easy as my fix was. You helped me fix my Firebird by happenstance. I'd already put a new cap and rotor button on a brand new distributor with about 700 miles on it and new sparkplugs and sparkplug wires and it still was running crappy. I'd never would have suspected it was something that I had already "fixed" without taking a close look at things again while I was taking pictures of things for you. You really have to stick your head in the engine bay far back to see that rubber vacuum nipple on the very bottom back of the throttle body.


Don't ever buy anything Dorman makes that is rubber.

This is the second time I've been burned by a Dorman product that has rubber in it

 

Ok, so I tried a smoke test with a smoke leak detector kit. Here's what I did and what I saw.

I disconnected the rubber hose from the hard line that eventually leads to a check valve and the brake booster and the other end goes into the intake block.
This is where I put my input tip for the smoke to be pumped in (in the hardline)

I plugged all the vacuum ports coming off the TBI except for the one going to the EGR valve I think... ( I just missed it when I was plugging ports) I also plugged the one port on the back of the TBI

I took the air filter out of the air cleaner housing, then tightened the lid back down and left it on, over the TB.

I disconnected the snorkel flexible tube from the metal intake tube that has the Thermac sitting on top of it, and Plugged the intake snorkel going to the TB and air cleaner housing.

Then I started pumping smoke and watched...
I saw smoke coming from the areas I mentioned before, out the base of the thermac, that rests on top of the air intake tube, around the top of the air cleaner ( the perimeter ) out of the port of the air cleaner where the CCV tube connects too and some coming out of the hole in the EGR valve. However it was hard to see anything because of all the smoke billowing out of the areas I just mentioned, mainly the CCV tube port and the Thermac, also the connection between the circular part of the air cleaner housing and where it branches off into the tube part, apparently that isn't sealed very good.

so what I did next was I opened up the air cleaner housing and stuff rags into the port that leads to the intake tube, to block off that passage and stop the smoke from coming out of the thermac. tightened the lid back down and pumped smoke again. This time it looked like most of the smoke was coming from out of the CCV port hole area. and still a bit from the EGR valve, but again I couldn't see much because of all the smoke.

So then I took the air cleaner assembly completely off, and I had all the TBI vac ports plugged with rubber caps, except for the EGR valve port I think (again I missed this and didn't realize until I was done) This time when I pumped smoke I had tons coming out from the top of the throttle body, but when I looked down, it didn't look like any was coming from the butterflys, but it was coming from a hole inside the TB that is right in front of the IAC (Idle Air Control Valve) as you can see in the picture. Does this mean my IAC is completely open?

To recap where I saw smoke:

1. a bit from EGR valve hole, not the gasket but the unit itself.
2. tons from the hole inside the TB that is right in front of the IAC valve
3. and other areas that you guys say doesn't really matter like the thermac, CCV port hole, and air cleaner top etc...

Where I didn't see any smoke:

1. none from any part of the intake manifold perimeter, front, or back.
2. No other vac lines or vac connectors
3. none from Evap canister or surrounding area.

Did I do this test right? it was kinda hard to see with all the excess smoke from the other areas, and what do you guys think about all that smoke coming from out the hole inside the TB that sits right in front of the IAC valve.

AFTER I WAS DONE WITH THE SMOKE TEST:
I started the car, with the TBI vac ports still plugged (except EGR port) and air cleaner assembly completely off, and open hard line (vacuum line) from where I removed the smoke tip, so it was still disconnected from the rubber hose that leads to the check valve and break booster. Here's what happened, my car started and sounded terrible, I think because it was trying to suck in all that air from that 1 hard vac line that goes to the break booster, BUT my car was idling at around 800-900 RPM...... I turned the car off and started it again, same thing 800-900 RPM, felt kinda rough though and I went under the hood and put my thumb over the hard vac line that goes to the break booster and it immediately stalled out and cut off. I went back in and started the car, 800-900 Rpm. Does this sound right and make sense? I got excited because RPM's were lower, but I can't obviously drive the car like this, and I bet when I hook everything back up, it'll be back to it's 1600-1700 rpm idle...

MY THEORIES:
I don't think the ECM is telling the IAC to do anything, adjust, I think the pentel is probably still in the exact same position as when I bought it and put it in...therefore the engine doesn't know how much air to get so it's just getting whatever it's getting with the IAC in whatever pos. it's in. Remember I can't get my ALDL to make my service engine light flash me a code 12 (diagnostic mode) it just stays steady. Something isn't right about that. I could try to back the pins out of the ALDL connector and try to jump bare exposed wire, to guarantee I'm making a good connection and see what happens?

From what I could see... I didn't see any leaks from the intake manifold or other major areas...just the ones I mentioned.

Thoughts???

oh also, I fixed some lights, etc, and working on getting my high low beam to work again...saw a video about loosening two screws on a white box on the side of the steering column and adjusting it's position then retighten. It has a metal arm that goes to the lever on the steering wheel, and on the other end a spring loaded mechanism that switches from hi to low beams. also lubed up my hood latch release cable.

 

IAC valve connector wires/voltages with the key in the ON position and IAC removed/not plugged into the connector:

Lt. grn/blk wire = 0.11 V
Lt. Blu/Blk wire = 0.26 V
Lt. Blue/Wht wire = 0.01 V
Lt. Grn/Wht wire = 0.02 V

Correct me if I'm wrong, but shouldn't one or two of these terminals when I have my test leads on the voltmeter (one on the ground terminal of the Battery, and the positive test lead probing the pin in the connector) be showing battery voltage like 12 V... When the key is in the ON position in the ignition lock cylinder.

Does this mean my connector is BAD, or I have a break in the wires somewhere in the Lume. I did wire this connector up because the old one was cracking off and stuff, but I'm pretty darn sure I connected the right wires to the right ones on the wiring harness, using the locking clip on the connector as my guide as to which wire connected with which one on the wiring harness, due to all the wires on the new connector were black.

If my IAC valve isn't receiving power... then it can't do it's job correct?

Also I tried plugging in the IAC valve but had it unscrewed and outside of the throttle body, so I could watch the pentel, I started the car for about 3 seconds just to see if I could see the pentel doing anything and it did NOTHING, didn't move at all...

Thoughts?

 

Also, does the IAC valve has its own fuse in the fuse box located under the dash near the steering column? And if so, what AMP is it and what number, or a picture of its fuse location?

 

I ain't forgot you. I been fat and lazy this morning. Going over to my friend's to package up some neon signs and strap them to a wooden pallet. Be back later on.

 

Find a bowl that will fit and seal like I did and something to weigh it down so it makes a good seal. If the air cleaner stud is in the way then with your left hand spread your index and middle fingers into a V and press down on the plastic clips on the fuel injectors then use you right hand to spin the air cleaner stud counterclockwise to unscrew it.

Plug up the little short CCV rubber hose on the end of the metal CCV breather tube. disconnect all the vacuum lines from the throttle body and use your rubber plug kit to plug them all off.

Very little smoke should be able to escape now and you should be able to get more smoke pressure inside the engine letting you find leaks easier.

After doing this for a while unplug and reconnect each vacuum hose to the throttle body one at a time and test again.





Pittsburgh - Noid Light and IAC Tester Set 11 Pc - Harbor Freight

The Noid Light and IAC test set can come in handy.

A handheld MightVac vacuum pump can be used to test the vacuum diaphragm in the EGR valve, the one on the end of the air cleaner snorkel, and anything on the other side of a one way vacuum check valve under hood in the vacuum system. The smoke test you are doing won't be able to find vacuum leaks on the other side of a one way check valve. It could if you removed the one way vacuum check valve from the vacuum circuit but on a car this old you will just break the plastic nipples off the check valve trying to remove them.




Mityvac - Handheld Vacuum Pump - Harbor Freight

 

Does it have to be gumbo or will chicken soup work 😝

 

I picked that one out of my pantry because It is one of my favorites. I guess Chicken Noodle would do too.

 

I tried a bowl, weighted down with a motorcycle battery on top of it for good weight, still had smoke leaking out...I tried duct tape and plastic bag with the bowl, still had smoke leaking out.... it's like I couldn't get a close to air tight seal...

I removed the throttle body spacer, the one that has notches in it and has a paper type gasket on top and bottom of it, and goes over the TB, tried to seal it up with this part off, still leaking from the rubber boot area where the injector wires go into the throttle body (and still in some areas where it's supposed to be flush against the base of the TB)

I'm going to put some RTV around the rubber gasket that slides into the base/side of the TB for the wires for the injectors, see if I can't stop that leak, because that became my biggest leak.

QUESTION:
Would it be ok to use just a little bit of RTV in combo with the paper gasket that goes on the spacer that goes over the TB, because that paper gasket isn't sealing ****...could I put a little bit of RTV on the bottom of that gasket and a little on top of the gasket then sit the housing spacer down on it?

I measured the diameter of that metal housing/spacer for the TB and it looks like if I can find a cylindrical object around 5 3/8'' diameter and 3'' tall I can put it right on top, so I 3D modeled that and I'm 3D printing it now, it'll be done printing around 8pm tonight.

ALSO I SAW SMOKE coming out of the bottom side of the TPS...?? that's weird....is this a problem? If so can I just put a bit of RTV around where the TPS mounts to the TB, not a lot but maybe just enough to get a tiny bit of squeeze out and seal whatever that leak is happening at the base of the TPS?

I saw just a tiny bit of smoke coming out of the holes in the EGR valve, not too much though.

ALSO I SAW SMOKE coming out of what looked like the spring that goes up against the TB and attaches to the Throttle arm or lever with the Throttle cables etc... I read somewhere that the bushings in this apparatus can go bad and cause a leak?

Other than those areas, the only other smoke I saw was basically where I was trying to seal the TB up, but not from the bottom gasket that sits on top of the intake, that looked good to me, and the sides, front, and back of the intake gasket area also looked good, didn't see any smoke..

I want to try and get a true seal on this TB and do a smoke test again without all the extra smoke just leaking out, so can I use the RTV like I asked on the areas that I mentioned.

If the bushings or whatever are bad or something on the Throttle arm apparatus, how do I fix that?

****** THANKS FOR HANGING IN THERE WITH ME AND HELPING ME!! *** Note: I tried to use a chunky potato soup can at first lol

I changed all the spark plugs yesterday and set the gap to 0.35, they were AC Delco plugs. Haven't started the car with them because I wanted to get this smoke test out the way, but I want to do it again with the TB SEALED and not leaking smoke everywhere.

I also hooked up each vac line that goes to the TB one by one and smoke tested those, and didn't see any leaks there...MAP sensor, PCV, etc...

 

Man they can't invent a teleportation machine fast enough.

I need to go back and reread the thread to see what all has been done so far to reset my mind again. I need to un-assume things I might have assumed so far.

 

While waiting on other answers, I figured I'd try to see if I could get my AC clutch to engage by jumping the connector and it did engage. So that's good. So then I figured I'd see if I had any Freon or pressure in the system by hooking up gauges to the high and low side of the system. It seems I was able to hook up the low side with a quick disconnect from my gauge, but when I went to hook up the high side with a quick disconnect from my gauge, I couldn't get it to snap on or fit - it was acting like it was too big for the fitting on the line. I know these fittings only fit one way - either the high or the low, and I don't think I have it backwards, but why can't I get the high side quick disconnect to attach to the high side on the line?

Does this fitting on the high side line look normal for a R134a system? Because I'm pretty sure the 1992 Camaros run on a R134a system, and as I mentioned, I got the low side to connect. Do I need a different fitting on that high side line, or do I need an adaptor on my high side quick disconnect? If so, can you send me a link for either/or?

 

I been out all day running errands with a friend then working on his gaming computer.

Our 1992 F-body cars are R12 Freon. They have the fittings for R12 unless the air conditioning system has been converted to R134a.

Our 1992 air conditioning systems are different than the 1991 and earlier F-body cars.

 

That's weird, when I looked it up I thought it said it was 1992 when they started converting over to R134a. But because I was able to fit the quick connect on the LOW side does that mean that someone changed out the low side to the R134a already, but not the high side? Because it's only the high side that won't fit.

So, to convert this to the R134a, all I have to do is go buy one of those retrofit kits from R12 to R134a? And basically swap out the fittings on the AC lines, high and low sides?

 

UPDATE: I managed to get the old R12 fitting off the high side and put a R134a fitting on there, so now both my low and high side have the R134a fittings. My car only blows air out of the top defrost vents. I figure I might have a vacuum leak preventing air blowing through the other vents in the car, but I didn't think this would affect recharging the system with Freon. I jumped the connection to force the AC clutch to engage, and it did. So I figured I could just have that part jumped temporarily to suck Freon into the system and once it had a bit in the system, I was just going to plug it back up normally instead of being jumped, and let the AC clutch engage by itself The problem is, when I hooked up my gauges and screwed in a can of R134a, and jumped the connector with the AC clutch engaged, it wasn't sucking any Freon from the can into the system. WHY? How do I fix this? I made sure that the quick disconnects on the high and low side were tightened down to make sure that the shrader valves were decompressed to allow fluid into the system. And made sure my low side part of the gauge was open. High side was still closed on the gauge. The pin that pierces the can was backed off to allow Freon to move thru the line, but none was moving through the line.

Even if I only have air blowing through my defrost vents, I still should be able to recharge the system....right?

 

Freon just doesn't disappear out of you AC system unless it has leak somewhere.

Do you also have a vacuum pump for AC systems to go along with your set of AC manifold gauges?

You need to be able to pull a vacuum on the AC system down to at least 29.92 to 29.97 inches of Mercury then close the valve on your manifold gauge set to seal the AC system and turn off the vacuum pump. It needs to hold that same level of vacuum and not leak down.

I'm 100% not an AC system expert.

I do the vacuum leak down test but I let mine set for like half the day and check it for leak down. When I know the system is not leaking I then pull a vacuum on the AC system overnight. Both of these are way longer than people say you need to do them for. Working my AC systems ain't my day job so I can spend all the time I want to doing it because I ain't getting paid to do it anyways and I'm not in a hurry to get to the next AC system job.

 

I have a vacuum pump but the screw on fitting from the pump line doesn't fit the gauge threaded fitting, so maybe I need an adaptor for that. I was going to pull the vacuum until I ran into that issue.

As far as Freon already being in the system, I don't think there was any, and if there was, it was very little. I could depress the shrader valve on the low side, and nothing came out. It's probably had a slow leak for years and finally ran out.

When I turn the max AC on and the fan on high, the AC clutch doesn't engage but it still blows air out of my top defrost vents - and it's not cold air. Even if the vacuum line was off somewhere around the control side inside the car, shouldn't it still accept Freon into the system? Because right now, it is not sucking any Freon into the system. When I look at the glass viewing window on my gauge, there is no Freon going through it.

 

I'm not really wanting to get into AC system repair right now because it ain't my thing and it's hard doing remote diagnosis over the internet.

I do remember when my friends got like a $400.00 kit of automotive AC service stuff so we could service our cars it came with a vacuum pump, manifold gauges, hoses, and fittings I had to get a couple additional fittings. I think one was for these newer resealable cans of R134a and maybe the other was an adapter for the vacuum pump to connect to the manifold gauges. I also remember that the instructions for setting the proper oil fill level for the vacuum pump were wrong for the oil fill sight glass that was actually on the vacuum pump. Once the vacuum pump oil fill level was right it actually worked right.

 

Also when you did the last smoke test with everything capped and plugged off and the bowl on top of the throttle body sealing it off I forgot about plugging up the exhaust system too. smoke pressure will come out the exhaust system. No matter where the engine stops some cylinders will have an intake and exhaust valve open at the same time. Put some of those rubber gloves on the tailpipes and seal off the exhaust exits.

I want to make 100% sure you don't have any intake manifold leaks.

I see what looks like a new IAC valve on your throttle body. Was the Minimum Idle Air Bleed procedure ever performed? I remember mentioning it but saying I didn't know how to do it manually with the paperclip method because I do it with my Snap-on scan tool.

There is also another test I can do with it that turns on the fans and exercises all the relays, solenoids, and valves on the car. You can see, hear, and feel if everything is working. IDK if there is a way to manually do this without a scan tool.

Did you get that noid light and IAC test set?

Also remember leaks above the butterflies in the throttle body don't matter. This includes the TB spacer & gaskets & the air cleaner assembly.

Little bitty air leaks around the PVC and CCV rubber grommets in the valve covers don't matter vary much either. They should fit nice and snug and not leak but it doesn't make for an 1800 RPM idle if they don't seal perfectly.

There will be a little bitty amount of smoke leaking around the throttle shaft on the throttle body on both sides. There should not be an excessive amount of smoke leaking around the driver side throttle shaft. There is no seal or bushings between the throttle body and the shaft. The throttle shaft rides in the throttle shaft bore in the casting. The casting wears out over time and can get oblong and the shaft fits sloppy on the driver side. The throttle cable and return spring are always pulling on the shaft on the driver side of the throttle body. You can grab the throttle lever and check for play. It will mostly be front to back vs up and down.

 

I knew I wasn't crazy because I was thinking that somehow this can was re-sealing itself when I recall the old ones didn't! So, with that in mind, that means I can never get this can to release Freon without getting this new fitting. Because every time I back out the piercing screw, the can reseals itself, not letting any Freon in the system. I just went and got the new fittings so that the new resealable type can will work.

I haven't gotten the IAC noid light and IAC test set yet.

And I haven't done the minimum air bleed procedure because I don't think I can. Because from what I've read with this OBD1 system, you're supposed to jump terminals A & B on the ALDL and that will put the car in a diagnostic mode and from there you can do these kinds of procedures. However, I don't think my car can get into diagnostic mode because when I jump terminals A & B my "service engine soon" light just remains on steady - it doesn't flash the code 12 (diagnostic mode) like it's supposed to. So, if it's not in diagnostic mode, then it's not going to do any kind of re-learn, I assume.

I don't have any play at all in the throttle body arm/lever - front to back or up and down.

I'll plug up the exhaust and try out my new 3D printed throttle body seal and do another smoke test to check for leaks mainly around the exhaust manifold - both front and back and sides - again. Let's say I don't see any smoke, what do you think could be causing the high idle then? EGR valve? The fact that my IAC maybe never got a re-learn? Also, what about the voltages that I mentioned on the connector going to the IAC....how low they were (almost none, with the key in the "on" position, as well as I tried it when the car was running.) How many volts is it supposed to get minimum, because I think the voltage changes based on how much throttle the engine is getting. The highest I saw was 0.2 at idle. I didn't try to give it gas and check for voltage change.

 

Yeah if you don't have the correct can tap for the newer re-sealable R134a cans then nothing will flow out. I just took what I had to the parts store until I found what I needed to fit what I had. Same for the vacuum pump fitting too.

The smoke test is also a good way to find EXHAUST system leaks too.

The massive vacuum leak from a wide open IAC valve in its parked position.

If your ECM isn't working right then it's probably not controlling the IAC valve. Your IAC valve will be in its wide open parked position letting all the air in.

I made the mistake of assuming we had a properly functioning ECM and IAC system to begin with.

That set of fuel injector NOID & IAC test lights you will use one of the two GM IAC test lights depending on connector type to plug into the car IAC wiring harness to see if the ECM is telling the IAC what to do.

The actual IAC valve usually gets dirty or gummed up where it seals to the TB and it gets gummed up inside where the stepper motor drives the output shaft. The gears teeth/threads get dirty and gummed up. You can't use any kind of harsh cleaner on the inside parts. Yours looks new so you shouldn't have to fool with taking it apart and cleaning it. The stepper motor part of the IAC valve hardly ever goes bad. The coils windings can be checked for resistance across certain terminals on the IAC valve. I think 40 to 80 Ohms.

 

I just finished doing the IAC NOID Light test. I plugged in the NOID light to the 4-terminal connector for the IAC. Pretty sure I put it in correctly because there's a notch on top of the NOID light that I guess is supposed to line up with the notch in the retaining clip of the connector. I turned the key to the ON position. There are 2 lights in the NOID light and one of the lights just flashed once when I turned the key to the on position, and then went out. Then I started the car and I was getting no light at all. I tried flicking the NOID light and connector and shaking the wire harness a bit to make sure there wasn't any super loose connection somewhere, and still no light. Tried this 3-4 times to confirm - no light.

This strongly suggests that I'm not getting power to the IAC.

I spliced in a new connector because the old one was cracking and falling apart and I'm pretty sure I wired it up correctly and everything felt tight. Is there a wiring diagram or something that shows me which wires in the wiring harness going to the connector are supposed to be the ones supplying voltage or power, so that I can test the wires before it reaches the connector to see if it's getting power there? Then it may suggest I have faulty connections where I spliced it but I doubt it.

Suggestions??