I had the pleasure to drive my dads 90 3.1L RS Camero for a few days.

Had the following problems on it.

First day:

Drove 18 miles to work. Pulled up to stop. Car idled rough, tried to die. The car also tried to adjust itself. Ilde all over the place. Put foot on gass while holding break. Finished driving to work. (I was warned of this problem)

Drive home was fine.

Second Day:

Car runs fine. A little rough idle but no problem.

Third Day:

Car runs fine to work. 18 Miles run back is a different story. Cruising 79 the speedo drops out, the tac acks funny. The tac goes up and down slightly.The engine surges up and down. So I slowed down and started to think I needed to pull over. But the speedo came back. Everything was fine. Did this three times. The speedo would be all over the place. Then die. Then the car would act up.

I thought for sure when I would get home. It would idle all over the place. Nope. No problem.

Upon Farther inspection that night I noticed a loose/corrorded battery connector. So I replaced that. The guages in the car that was flexuating a little. Does not seem to do that anymore. At least around town.

However, when I was turing a corner. The car died. I chucked it in neutral and started it right back up. (I was warned of this problem)

So I have two problems I was warned about. The mechanic a while back did find a bad vac line and fixed. That caused the check engine light to go off. During all of this time except for the stall. The check engine light never did come on. Do you think I can pull codes. My experaince in cars like this. Pre OBD-II most of them only pull codes when you got a bad check engine light comming on all the time or comes on during a problem.

I'm sortof happy this is my dads car. I wouldn't be able to stand driving it until these problems are fixed.

Any help or ideas would be appriciated....

Thanks,


Josh

 

Clean IAC is a start. I have the same problem. IAC (Idle Air Control) valve gets dirty with carbon deposits. Take it out but careful not to push or pull the pintle, you can damage it and have to replace it ($70). Clean it with carb cleaner beware that it doesn't have methy eithly ketone. Do not soak it in cleaner . spray it and take a brush to it.

 

Anytime you come to a stop or during a turn and the car dies..what are you doing different then if your going in a straight line??..your applying the brakes...right??...the Brake booster is often overlooked and some think if you have a hard pedal then the booster is bad..but what if you have a small leak in the booster?.Easy check..disconnect it ..plug it and drive it very careful and do your turning or whatever made it die...or you can start it up..let it idle and make notice how it idles and press the brake pedal and if it the engine idle gets irratic or becomes unstable.Release the pedal and see if it smooths out..if it does bad booster.Had the same issue on mine and had a booster bad and I found an open charcoal canister solenoid stuck open.Big vacuum leaks.thats an easy test too..remove the hose running to the solenoid and blow through it ..if you can't thats a good sign..if you can its bad.The hose runs right to the intake manifold..if its open then you have a vacuum leak,and its a hidden one that some overlook.Smelling gas at a stop light is often a good indicator of a bad Charcoal Can solenoid.

 

i have the same issues with mine its but when i let go of the break and hit the gas, it struggles then dies. but takes about five or ten minutes to start again. it doesnt do it every day though. it stared when first got i chaned the fuel filter. it was ok. drove a day or two sat for two weeks. drove for four days, changeed the plugs n wires(both bosch) and it cut off twice the same day. what do you make of that?

 

fuel injectors..

 

EGR...

 

ok i have just rebuilt my car and prepped it for mounting a turbo charger to just waiting on my up and down pipes from the weld shop and im good to go but i have ran into and fixed these same problems. step by step im gunna tell u everything to check and yes i know this is an old thread but the info should help others check all your vaccum lines the do go bad... check your fuel pump tank seals lines all of it if u are getting weak pressure your car will idle like an angry gokart... then check Throttle position sensor, and IAC yes they are different components but yes both could also mess with your idle speed and sluggish response as well. then check and make sure your o2 sensor is working right i didnt realize mine was thrashed until i hooked up an air fuel ratio gauge and it read lean..... yet i take it in for diags and my mechanic says its fine... all of those things have small parts in your engine and fuel management but they will affect how your car idles...

 

I was looking around for help with an idle problem. The car idles good when it's first started and shortly thereafter (open loop?). but after maybe 5-10 minutes of driving when I stop the idle is really erratic. It's got a new TPS, IAC is clean, ran seafoam a month ago, new fuel filter last year. I also had a moron replace my fuel pump last year and ever since there is a loud whine fron the tank and when i take the cap off there's never any pressure or vacume like there used to be. Could that be the problem?

 

Well if you suspect the pump is to blame you can check the fuel pressure first and foremost.

Have you checked the e.c.m in case there are any fault codes. The how-to is on these boards if you do a search (including the code meanings).

There might be a vac leak which will affect idle, you can use a can of carb cleaner over the vac lines which will help detect a leak (if the idle fluctuates then you have found a leak)

Also just because the IAC clean doesn't rule out a failure. You could try tapping the IAC motor gently, if the idle changes it could be the stepper motor in the IAC failing. Matthew

 

Are you running the stock injectors?

 

2 years ago my engine kept dying and it turned out my injectors were shorting out. My mechanic replaced them with some out of a Buick he said... So I'm not sure what injectors he put in..

 

If this was an earlier car I'd be suspicious of the MAF sensor. Since mine has a MAP sensor is there any way to check it? I couldnt find alot about MAP's on here, how they work, or if they go bad...

 

MAP is similar to a vacuum choke on an older carb, but the diaphragm pulls on a device similar to the TPS, a potentiometer, instead of a choke linkage. They do go bad. Check the voltage between the green and black wires at idle. Remove the vac line from the bottom. If anything comes out of the sensor, replace it. Check the vac line for cracks/melting/breaks. Other than that, there really isn't much to do.

 

You said your speedo was acting up as well? Hows your vss?

 

Thanks, where is the sensor under the hood? and I'm assuming you mean check the wire voltage with it connected, and pull the vac line off ith the car not running.

Oh, and it wasnt me having speedo problems. I hijacked this thread rather than making one with the same name for the same reason.

 

It's on a bracket bolted to the cowl by the air inlet/evaporator in the heater box (where the lines from the heater core come through the bulkhead). It's the only thing in the entire engine bay that has a green connector, a 3-wire. Trace the vac line from the small port on the back of the upper plenum, the one by the lifting eye (as opposed to the one where the brake booster connects). And yes, you can't get a vac signal to the MAP with the engine running if the line isn't connected, so you need to leave the line on there when taking the voltage reading.

 

Voltage reading looks like its gonna be hard to get. The plug is all weather proof so the leads cant go in behind the wires, any trick to gettin it? I'll take a better look at it tomorrow at the shop when I have my DVOM. and post up what the volatge reads between the green and black.

 

You can get the meter leads in there, but you might need to fight with them to get a reading. Or, you can go to a place that sells medical supplies and buy a box of what is called T-pins, which are smaller than the meter leads and are good for a number of things. Stick the pin in the back of the connector next to the wire and put the meter lead in the center of the T, which holds it until you're done. Just make sure that the pins don't short together.

 

where is the idle control valve

 

Hello i have a 1990 caamro rs with a tbi throttle body carburetor, i changed the distributor, the egr, the ignition coil, the fuel filter, fuel pump, spark plugs, spark pug cables. Yesterday i got it to run i drove it everywhere everything was good but then as i made my way back home and the car shifted the car idled out and i lost power the car was idling and eventually it went back to normal. I got home and when i wanted to turn it back on, it wont do it it starts and it sounds powerless extremely rough and after 10 20 seconds it shuts off and it does it over and over and over again can the problem be the idle air control valve the map sensor or the throttle position sensor ? i need help

 

1. You sure you have TBI? If you do, it was a swap from either a van or an S10, as the F-body came stock with multi-port fuel injection.
2. What kind of tools do you have? For most things, you will need a digital multimeter. You may also want to either rent or buy a fuel pressure gauge to test the fuel pressure.
3. Find the diagnostic connector by the fuse panel under the dash. You will want to put some sort of wire between the 2 terminals that are next to each other in the top right hand corner of the connector, and then turn the ignition key to the RUN position (where it is when the engine is running) but don't start the engine. The Service Engine Soon light will flash out trouble codes. You want to write down any codes other than 1 blink-2 blinks and post them up here.
4. Calm down and take a deep breath... These old cars just need some TLC sometimes and you've replaced a lot of parts, but there may be others that need to be taken care of as well.

 

what do you mena by "You want to write down any codes other than 1 blink-2 blinks and post them up here.

 

Code 12, 1-2 blinks, is the standard "engine not running" code. No code 12 is one problem, and any other code 1-3, 3-3, etc, is another (or more). As in my examples, code 13 is an oxygen sensor fault, and code 33, in your case, is a MAP sensor reading high fault... The trouble codes are basically where the ECM, computer, is reading a system error, and it's trying to tell you what and where it is, with the limited brain it has.

 

oh ok well i haven't replaced the map sensor the idel air control valve or the throttle control sensor so i think i might replace those and then i will do the diagnostic, also d oyou know anywhere i can get a diagram or visual of were do the air lines hook up too i took the car to a mechanic and i think he moved my air lines around. He was trying to charge me too much for a few part replacements and so i guess out of anger he dint connect certain lines back when i towed it home and open the hood some lines that are found in the back by the distributor were disconnected and i connected to the outlets that i found where they might go but i am not sure so i need a diagram or a visual aid to hook them up where they are suppose too i have a book based on a break down and rebuilt for the camaro but it docent say O.O

 

There SHOULD be a sticker under the front edge of the hood, labeled "Emissions Hose Routing" . All of the vacuum, AIR, PCV, etc lines are on that label as to where they come from and where they go. It may be covered in greasy crud, or worse, paint, in which case you'll need to look it up or ask someone.

Don't replace ANYTHING until you get the trouble codes and the vacuum lines and whatever else is loose under the hood sorted out, or you could just be wasting about $100, if it turns out that the lines and whatever else was disconnected was the problem. Just because parts are old doesn't mean they don't work...

 

so you can see what my engine looks like i am uploading pictures of it on my profile to see if its a fuel injector or tbi O.O

 

ok i will scan first replace later

 

ok so i scanned my car and it flashed error code 33 which is mass air flow (maf) sensor signal voltage or frequency is high during engine idle or manifold absolute pressure (map) sensor signal voltage is high during engine idel (note: engine misfire or unstable idle may cause this code) at the moment i cant start the car it starts and it dies soon after maybe 10 15 seconds and it does it over and over again so i dont know if i have to fix that before i can scan again

 

OK so i have a line that is cut that runs from the piece that controls the cruise control this line is suppose to run from the condenser ball that is located in the front driver side corner of the car and it runs up to the cruise control any one know if it goes there ?

 

Yes, there is supposed to be a T in that vacuum line, which should run from the back of the upper air intake plenum. The line should come straight towards the vacuum ball, and the cruise modulator should be T-d into it. If it's not connected, that would be why you're getting a "low engine vacuum" code.

 

Well i have it hooked up to the ball under the battery and the cruise control but i dont know were it hooks up behind the air intake prelium

 

The line gets hooked into the other side of the T where the large line from the brake booster connects, usually...

 

ohh ok so does it connect to the T in the back of the intake were there is like a coned shaped fitting O.O

 

I think you're referring to the vacuum check valve that's supposed to be back there (and you're one of few who still do since most break)... Yes, I do believe it's supposed to connect there. There are 2 fittings in the back of the plenum, one being towards the MAP sensor, and only for the MAP, and the other for the cruise and vacuum ball and the brake booster on the other side. The cone fitting is the check valve for the heat control vacuum switch, which also runs off of this line. The line you have loose should connect to the large port on the cone side of the check valve, IIRC (I haven't seen one in person since 2004).

 

well i posted a pic of the back of the intake and you can see it cuzz i am not sure which one O.O its getting really frustrating you can see the pictures in my profile

 

Yeah, someone has that backwards... The line coming off of the straight valve outlet is supposed to be in the side outlet and your loose line is supposed to be in the one that's currently occupied. The black line running into the elbow at the end of the check valve isn't supposed to be curled around but straight... It's the other line that's supposed to be curled around to meet the check valve. Just pull the line going into the HVAC elbow off and put the elbow on the side, and then the loose line on the end.

 

so the end with the elbow has to be on the top end and the lose end has to be on the straight end ?

 

ok so i switched the lines i put the elbow line on the entrance that was free and i put the line that runs to the cruise control and well the car started but it its rough and it turns off soo i am guessing i need too change out my map sensor or my idle air control valve O.O i am a bit confused now O.O RAWRRRRRRRRRRRRRRRRRRRRRRRRRR REPTAR FRUSTRATED

 

No, you need to disconnect the battery and go through the idle relearn procedure by letting the engine warm up to operating temp (fan turns on and then off again). This resets the computer to use the stock tables, and will allow you to see if any new codes pop up.

 

OK so my car is not working O.O rawrrrrrrrrrrrrrrrrr i changed my idle air control valve my map sensor and my troddle body position sensor and the car starts but no power when i hit the accelerator it shuts off i have a new fuel pump and fuel filter my neighbor informed me that it could be that a few pistons are not working O.O any one have any ideas for i am lossing my mind

 

Do you know how to pull the trouble codes from the ECM? Need those to know what the ECM is thinking is wrong...

Pull out the spark plugs and note the color on the tips... That will tell you what's going on in the chambers.

 

how do i pull the codes from the ecm ?

 

The diagnostic connector is behind the fuse panel, where your left knee is when you're in the driver's seat. You unscrew the retaining screw and pull the cover off, and the ALDL is right there with the fuse panel. There will be 2 terminals in the ALDL that are right next to each other in the top left hand corner (towards the steering wheel). Connect the 2 with a wire and turn the key to the RUN position WITHOUT starting the engine. If the diagnostic circuit in the ECM is working, you will hear the radiator fan turn on and the idle control motor will close as well as several other solenoids. The Service Engine Soon light will flash in a sequence, starting with 1-2 (code 12). Write down and post any other codes (code 12 is not necessarily an error code, it means that the ECM isn't receiving reference signals from the ignition module... It's when code 12 doesn't appear that there is a problem).

Again, you need to pull the spark plugs out, if for no other reason than to make sure you have good spark (should be bright white and not red or any other color).

:edit: Oh, and before you do ANYTHING else, disconnect the battery for about 15 seconds and then reconnect it again. If the code 33 is still in place, there is another problem in the MAP circuit, but you don't want the ECM to tell you there is a problem that there really isn't. And you should have reset the ECM to base tables anyways doing this after replacing the MAP and other parts.

 

i did erase the codes by disconecting the batery or removing the ecm fuse for 15 seconds and it continues to give me code 33 my neighbor told me that it might be a electrical cuss when i o to the book for code 33 it says that the voltage is high during idel speed so it has to do with the elcetrical work and i will check the spark plugs

 

I'll need to consult the 92 FSM I have buried under some stuff in my tool box in the garage, but you will need to check the MAP voltage between the green and black wires. I do know that you should NOT be reading 5VDC on the green wire with the engine idling and any sort of vacuum signal to the MAP. If the MAP is giving you a code 33, then your plugs will probably be black due to excess fuel in the cylinders.

 

well i am going to check the spark plugs today after breakfast but i checked my fuel pressure and its good just by turnign the switch it gives me 42 psi and it needs to be between 32 and 47 so its good, um i am going to check the map sensor later i found a video on youtube on how to do it so i will try it and is there any ways to know if a fuel injector is not working i found this video on youtube were it checks the coils resistance can that be a form to know if it is not working O.O

 

Fuel pressure is supposed to be between 37 and 47 PSI, GM spec...

To check the injector resistance (not really necessary at this point but you might as well), there is a 6-pack connector by your A/C compressor and thermostat housing. Disconnect it and use the meter on the injector harness side (should be the side with the bigger connector half, IIRC), and put the meter leads between the pink and blue and green wires (one bank is pink/black for power and the other is just pink, use the other wire if you can't get anything out of it). The resistance on this test should read about 4 ohms. If you get 6 or more, you have a shorted injector. After that, each injector itself should have no less than 11.8 ohms resistance, with a 10% variation between the highest and lowest.

:edit: And make sure the vacuum line running to the MAP isn't clogged, as that will skew the reading high (atmospheric pressure reading is full scale).

 

ok ill try it thanks for the help ^.^

 

so i have another problem my car is wearing the tires out uneven, about 2 years ago i changed the inner and outer tie rod ends and since then i am not able to turn the direction all the way the car does one of two things it docent move i have to press the accelerator to go or the car turns off, and this is the second time i buy tires can any one help with this problem

 

The stalling problem has to do with the other issues you're having with the engine controls system. There is no pressure switch on the 3.1 cars like there is on the 2.8's, so the ECM has no way of knowing when the steering is cranked to the max and that it needs to raise the idle speed accordingly (I'm assuming you don't fully crank the wheel at 60, right ? ).

As for the tire wear, how are the tires wearing? Inner edge (towards the brake rotor), outer edge, both outer edges, middle only, etc? Either of the outer edges (but not both) indicates that you have a toe problem due to improper setting of the tie rods (you did have an alignment after you replaced the tie rods, didn't you?). Wearing of both of the outer edges indicates underinflation, and wearing of the middle indicates overinflation. There could be other reasons, but we can't help until you indicate to us how exactly the tires are wearing out.