Okay so this is a brand new problem I have never had before. It appeared today after strictly messing with electrical stuff. All I did was check out the cooling fan relay, jumped the fan once at the relay, measured wires with a voltmeter, and hooked the fan back up. Wrapped some wires in electrical tape.

Anyway its very weird, I didnt do anything around the air cleaner assembly or anything.

The car cranks about 5seconds, never starts, eventually will stop trying if I keep the key turned. Repeats the same behavior, and after 2 or more tries, it will eventually start right up like it normally does. Has no problems while running. This behavior happens when the engine is cold and when it is warm.

What would cause this? Oh yeah, and giving it gas does not help at all. Still cranks for just as long.

Also it seems like there was a large vacuuum leak coming from the throttle body area when this problem first started. It sounded like a loud vacuum sucking in air. Never heard such a loud vacuum leak. But when I took off the air cleaner assembly to check it out better, it was gone. I put it back on, and it was there again. Took it off again, and it was gone. Put it back on, and its still gone now. However it still has the cranking problem.

A little minor history.. Brand new starter, wires, plugs, cap, rotor, pcv valve, ignition control module, water pump, egr valve, fuel filter, fuel pump relay, and more. Mostly back in october 2012, some more recent. I have been having a problem where I need to give it a little gas after a warm start (warm start only. cold start starts right up usually) or otherwise it stalls and dies after the idle dips below 500rpm (it happens fairly quickly, like it starts then keeps dropping til 500 where it dies unless I give it some gas). Also I have had the knock sensor disconnected for about a month and it seems the car hasnt run different the whole time.

 

Check fuel pressure, should climb up to 9-13 psi in a second. Try priming the system by cycling the key a couple of times, then see if it starts easier.

 

You know what I just realized.. I replaced the radiator fan relay and fuel pump relay the same day. Maybe the 2 relays I bought from Oreillys are bad. They are the MasterPro brand, the cheapest ones. Because my radiator cooling fan wasnt working and suddenly is working again (thats what I was messing around with today, and actually I did swap the relays at one point, though I swapped them back).

However, I am thinking this might be a bigger electrical problem. Random fuses keep blowing out, mostly just ones that have to do with interior functions, like door lock buttons, overhead light, cigarette lighter, etc.

I have a new battery (well 6 months ago) putting out 12.8V constant. I did have my 360w amp and 2 subs installed by a friend who I found out later doesnt know what hes doing. I hear a ground hum immediately after plugging in my deck, before it even loads up. If I unplug it and plug it back in enough times, sometimes it goes away but eventually returns. I still havent fixed it actually.

 

Sounds like a coolant temp sensor problem. The one on the intake manifold, they sell coolant temp sensors and senders, you need the sensor. Or maybe the idle air control valve, that could be the loud vacuum noise you hear sometimes...In the tech articles there is an article on how to clean and reset the IAC.

The cigarette lighter is a common problem with blowing fuses.

 

Forgot to say I replaced the coolant temperature sensor in the past month, trying to get the fan working. Now the IAC, I might need. I took it out the sender/connector that goes to it, and some of the plastic broke off (on one of the 4 prongs, not the outside plastic that snaps in). I put it back in, and it actually idles a lot better now. Its smoother and idles lower (about 400rpm less).

So maybe try replacing IAC and the sender that goes to it?

Yeah actually plugging something in the cigarette lighter, especially when the engine isnt running, is a guaranteed blowing of fuses. The lighter doesnt work, just the power from the slot. So hopefully buying a new cigarette lighter might fix the fuse problem, but the cigarette lighter fuse can be blown and it still blows other fuses.

 

I'd try cleaning it and the hole it uses in the throttle body first, before replacing it. I'd also check that the throttle position sensor is sending out the right voltage.

 

It has to be the IAC valve, I checked symptoms and I have all of them. Like stalling out when starting the engine when warm, but not cold. Had to give gas to avoid it. And now the idle RPM is lower than before. Been having a rough idle. This is good news though, I thought My fuel pump was going bad.

I will clean IAC first, I just found some good instructions on it

I cant find the TPS.. I have the Chiltons and have looked it up, and I know where that throttle cable is, I can give it throttle, I just cant find where the sensor is.

 

It's on the same side as the IAC and has 3 wires going to it.

 

Ok I cleaned the IAC and thats not it. I also unplugged it to make sure. I still have a giant vacuum leak near the throttle body.. Very loud. Doesnt seem to be coming from the tb gaskets or any vacuum lines. But the vacuum sound is definitely coming from near the TB. Im very confused.. Injectors seem a little loose but are spraying fuel upon throttle, and the vacuum leak doesnt seem to stop when I wiggle them... Where else should I check for vacuum leaks?


Which sensor with 3 cables? Its not the small blue connector in front of the IAC right? Its the bigger green connector close to the firewall?

 

Just to back up the earlier suggestion...look for a bad IAC...all the symptoms you described are the same that I had with my 87 TPI. I tried cleaning first and it did not help. I bought one new and it cured my symptoms....Something else to consider would be a cold start injector.

 

I think it might just be the IAC. I just double checked the vacuum diagrams and cant find any leaks. Im gonna go buy a new one. Also how do you plug the connector in correctly? I lost the orientation of it and didnt realize it fits in any way. I see the ABCD on the connector, and a 3 in the middle on the IAC. Im assuming with the 3 faced upright, A starts at the top left, the B top right, C bottom left, D bottom right?

 

I'm not 100% on that one....if the clip that lines the plug up is broken then feel around the top lip of the plug for remnants of the "clip" and you should be able to match that up with the iac

 

Well.. Ready for a laugh? Turns out I was plugging in the connector the wrong way.. After I took out the IAC to clean it, I just plugged the connector back in, assuming it only fits one way. It probably does only fit one way when both pieces are brand new, but mine are not, so it fits any way. Anyway, I just lined up the clip on the IAC to the larger clip on the connector, and now it works. For future reference, I believe the 3 on the inside of the IAC is upside down, then the A of the connector is in the top left corner, and so on..

So it probably was stuck, then never was unstuck because the connector was plugged in wrong. I never put it in diagnostic mode to pop the spring out, I just sprayed it with carb cleaner.

Edit: Never mind all that, Im having even worse problems now.. Sounds like a smaller vacuum leak.. Still having a lil trouble starting but not as much. Idle is way too low, like 500rpm.. It stalled out on me on a uturn. Car feels limp.. Maybe knock sensor being unplugged finally kicked in.. Im sure i need to adjust minimum air and everything to do with idling. I'll do it in the morning

 

Ok I replaced the IAC and still no better. The vacuum leak is definitely coming from where the IAC is. When I spray carb cleaner in the TB where it connects, it bogs the engine more than when I spray carb cleaner down the TB..

Also in diagnostic mode the IAC keeps clicking and trying to move, even after 30 seconds. I waited about 5 minutes and it never stopped.

Oh yeah engine doesnt run limp anymore when i did get it started with the new iac valve, but still has one hell of a time actually starting. I cranked it so much it didnt wanna crank anymore, at one point.

Remember this is all with a brand new IAC.. Is it possible my IAC connector is messing everything up? It does look kinda beat up

 

Well there is a vacuum leak at the IAC because that is how it functions, as a controled vacuum leak. The cranking forever problem leads me to the coolant temp sensor again...

You say that once it is running it runs fine no bogging down or strange driveability issues, it's just a bear to get started. The CTS controls the cold start fuel, if the TPS is bad it can think it is in flood mode and kill the injectors, though that is unlikely.

 

Yeah I just replaced the TPS thinking it was that.. The old one was definitely sticky and it runs better now, but didnt fix the problem. At first it started, although it was rough at first, didnt wanna move past 500rpm like it bogged down because of lack of air, but after about a second of bogging, it would start. Also, the behavior didnt change upon giving it gas... It still bogged for the same amount of time. Then it would raise to a 1000rpm idle and slowly (over 5 seconds) creep down to 500 rpm. I stopped the engine, then started it, and it repeated this behavior several times.

The 5 second idle rpm drop as soon as it starts is very weird because that never used to happen. Usually it maintains a steady idle. it used to start idling at 1500rpm cold, then dip quickly to 1250rpm after a few minutes of warming up, then eventually 1000rpm.

So I decided its ok for a test run.. Went around for about 10 minutes, then parked it back in the driveway.. Tried to start it back up and it cranks forever. This leads me to think some intermittent vacuum leak.. Im thinking that IAC connector, its getting more and more messed up since Ive been taking it in and out so much.

CTS was replaced within the past month.

 

Pull the tbi unit off & check the base gasket.

 

What is the condition of your fuel pressure regulator?

 

Will check Chiltons on how to check FPR.. Quick update though, I unplugged the vacuum hose that connects to the EGR valve, and the car started, although going through a similar rough phase.. I connected it back while it was running, since the vacuum leak was making the engine shake a little. And now it starts every time on the first try, although still with the same roughness. I dont apply any gas, and applying gas doesnt make a difference still

The EGR valve is only about 3 months old, but it was installed by a friend who I later found out doesnt know what the hell he's doing.. He screwed up all sorts of minor things that werent so minor, like not properly grounding an amp, not burping air out of cooling system, telling me its ok to just use a bigger fuse if it keeps blowing, etc etc

Car does seem to start up very rich, so maybe there is something with the FPR. And Ive been getting code 54 since I got the car. Also with a 1/4 or less of gas, it will stall out and die if I make a uturn, without fail. And starts right back up.

Also unplugged IAT and CTS (seperately of course) and neither of them are causing the problem.

 

Well it could be a bad egr solenoid, the egr should never at any time have vacuum at idle, put a vacuum gauge on it.

 

Well actually now it keeps giving me code 54 when it cranks and doesnt start. Flashes light right away when trying to start. Very odd.. Relay is still good, I tested it by swapping it. They both click too.

 

Starts every time when the vacuum cable to the EGR valve or to the intake from the EGR solenoid.. Basically anything in that line.. It starts rough tho..

I checked every single vacuum line and theyre all good.

Also when I do get it started, there is a huge leak from the IAC valve area (from the inside of the TB of course). Sounds like a loud vacuum. I know you guys said theres supposed to be a leak, but it bogs the car more when I spray carb cleaner there than when I spray carb cleaner right down the TB. Sometimes I can get it to go away when I put the air cleaner on, but sometimes its still there. It definitely wasnt happening before when the car started fine. also when I start the car it smells very rich.

Does this plus the code 54 indicate bad fuel injectors maybe? I sprayed carb cleaner on top of them and there was no bogging though. It doesnt seem like the fuel pump is out yet, especially since it will run forever when I do get it started.

The IAC valve connector is pretty ****ed up now. Theres some plastic stuck in the IAC valve actually.. But the metal is still good.. It still tries to push the needle/pintel in the IAC valve in diagnostic mode. In fact it never stops clicking, it keeps trying to push it out and never stops

 

Well Im completely confused.. I got it to start every time and also eliminated that loud vacuum noise/leak by just messing with all the vacuum lines again.. Mostly just plugging and unplugging them.. I drove it for 30 min hoping maybe the ECM is getting used to the IAC or something. It ran like a dream, better than ever, especially with the new TPS... Came back home, and now it cranks but wont start. Vacuum lines all look good still.. Im lost..

Oh yeah it wasnt running all that rich when I was driving it. I popped the hood before I turned it off. Didnt smell very rich at all. There was no vacuum leaks, or if there was, nothing audible. Now I try to start it, and after just 5 cranks, it smells super rich, inside the car especially, but under the hood and outside too. I tried with gas and without, since earlier it seemed to start better without hitting the gas, and nothing worked

 

first off spraying carb cleaner into the leak or TB will bog down the engine if you already have a vacuum leak because the engine is trying to compensate for the extra air coming in from the leak. fix the leak that will help. second unplug your batt or you ECM for about an HR to reset the comp and go from there

 

Yeah I know it will bog it down, I was just using it to test where the leak was coming from. I fixed the leak though, just by messing with all the vacuum hoses. The large sucking sound coming from the IAC is gone.

The way it keeps being an intermittant problem, the way it works in the driveway, then wont start when I come back, and the rich smell leads me to believe its a sensor problem.

I already unplugged my battery for a good half hour twice. I wasted a lot of gas thinking the problem was fixed and driving so the computer could relearn the car.

 

what about a leaking or stuck injector that would cause a lot if your problems

 

Yeah I think thats it.. After some online research, I decided to try to start it by flooring the gas pedal. It was sluggish at first, but then it started. The huge vacuum sound was there (i believe its the IAC overcompensating for the richness). I turned the car off and started it up again. Had to give it a little gas and it was rough at first, but when it was started it was back to normal. No large vacuum sucking sound from the IAC area, and the idle dropped back to a normal level. Now it starts right up every time.

I guess Im shopping for injectors today. Any suggestions? Ill probably just get stock AC Delco. Should I get the Z28 injectors for more psi? Im stock now but plan to put in a full exhaust. Still havent decided whether to swap the engine or keep the 305 and rebuild it when it goes. But either way, even if I keep the 305, I will always try to make performance upgrades.

 

Also what is this grey elbow and the hoses attached to it? This is on the passenger side..

There seems to be a slight vacuum leak at the elbow.

 

Kinda hard to see..but looks like a vacuum tree of some sort...I'm sure you knew that already...hopefully new injectors will fix the problem...funny thing about computer controlled cars, it always seems that one problem resembles the next. If I'm not mistaken I believe the knock sensor is there to make small timing adjustments. With the car stalling while making a u-turn at a quarter tank could be from the "sock" not being on the fuel pump...I have run into that with my old 84 Z28. Also it would not hurt to check the fuel pressure. AutoZone and other parts stores usually allow you to use rental tools to check it out. Just because the pump is pumping doesn't mean its enough. Before replacing costly injectors it may be worth while to check this. Also a $8.00 can of sea foam can help a lot. You pull the vacuum off of the brake booster while the car is running and allow it to slowly suck it up. You have to do this at normal operating temp. Then shut it off for five mites and start it back up and allow it to idle...hopefully you will find your ghost haha...

 

I used some Seafoam you add through the gas tank around September (4000 miles ago) around the time of my last tune up.. Maybe time for some more? Maybe buy the spray this time and do it like you said through the vacuum hoses so its more direct?

Yeah its some kind of vacuum tree but I have no idea what it goes to because its not anywhere in the vacuum diagram. I have checked every vacuum hose in the diagram like 3 times now, I feel like I know it like the back of my hand.

Heres another picture.

 

Hope everyone's ready for a good laugh.. Dont know why, havent checked oil in a while.. Of course it was way low.. Added 2 quarts and its still not at Full on the dipstick. It starts way better now, on the first try every time, but it cranks for a good 5 seconds. Also starts to idle at 1000rpm then slowly dips to 500rpm, over like 3 seconds. it idles rough too. Going to try to reset IAC and unplug battery

 

It the vacuum tree that you are talking about is closest to the air cleaner with one small hose to the top and two big hoses out of the side, then that is what controls your heater. Wow that is crazy with the oil situation...I know some 90's model 4cyl Pontiacs came with a kill switch that shut your car down if the oil was too low...but haven't heard of that in the camaros. If it was ran that low on oil for a little while it might be a good idea to pick up a quart of Lucas oil treatment and put in there. I use a quart with every oil change just because lol my 87' 305TPI carries 45 psi when cold and 35 when hot.this is oil pressure...and it has 154,000 miles on it...also the sea foam through the brake booster hose does an upper cylinder lube and clean. Just got done doing mine. It's something I started doing about every 3 months or so. If you decide to do this with the sea foam, don't freak out when your car starts to smoke smoke real bad...it will stop. That just means its doing its job and cleaning all the carbon and sludge build up on the intake. And if you suspect a sticky injector my opinion would be Lucas injector cleaner in the gas tank

 

I circled the vacuum tree I was talking about. It's the next thing away from the air cleaner after the heater vacuum setup that you were describing.

Also what does it connect to? That thing under the circle that's above the passenger side exhaust manifold and kinda over the valve cover too.

I will get the oil, fuel injector treatments, and the Seafoam

 

Well I unplugged the MAP sensor and it started up a little faster, instead of cranking for 5 seconds it cranked only for 1 second. Starts every time but runs super super rich all I smell is gas. Real strong too. Inside the car, outside, all inside my garage that happened to be open (car is outside).

I tried to clean the MAP sensor with electrical contact cleaner. Plugged it back in and it starts every time, although sluggish, but starts after only 1 second of cranking. Im hoping its just a bad MAP sensor. Ill get one soon and update

 

Yes good thinking on the map sensor. That would definitely describe some of those symptoms also. And it would make your service engine soon light come on intermittently. Think you may be on the right track....and the vacuum hose looks like it goes to the emissions. You should be able to follow those hoses to the smog pump and to the exhaust manifolds.

 

Well I'm at a complete loss... So I got a new MAP sensor and there wasn't much of a change from after cleaning my old one.. I'm gonna keep it anyway, even though it's a Master Pro part, but I figure why not have something new..

I also plugged my knock sensor back in, and I also plugged my fan switch back in. Knock sensor plugged back in is good. It accelerates through the RPMs much slower, but I can feel it pull the whole time now. Before it would pull hard until about 3k RPM and then just have almost no pull from 3-5k. However, now the fan is always turned on!! I finally got the fan to work again when turning on the A/C, but now after plugging my fan switch back in, it's always on!!

That damn vacuum sucking sound from the IAC valve keeps coming back intermittantly. And the car is still running rich.

So I'm at a complete loss and I'm kind of fed up with these weird computer problems. My battery ground seems OK, but I don't know where exactly to check the ECM ground. But anyway, I'm gonna buy a ALDL to USB cable, get some software, and get to the bottom of this. Because I don't even think a shop would figure this one out, and I've pretty much completely lost faith in all mechanics over the years.

 

Just curious, did these problems start around the time your friend installed the amps and radio ? I have seen some strange things due to improperly installed electronics. I would check to see if he may have run the power wire for the radio to the wrong place. Also for your amps are they run straight to the battery or to a wire that comes off of the battery ? Did he use an aftermarket wiring kit that plugs into the factory wiring harness for the radio ? Also does your fan stay on without the ac being on ? Because your fan is supposed to come on with the ac switched to on. If you have only one fan then it should come on at a steady low speed and when your car gets up to temp. It should engage the high speed. If your car has two fans then only one will come on with the ac turned on and when your car gets to temp. Then both will come on...and I agree about mechanics, there are so many that are not very good or just don't really know what's going on that it makes it hard to trust anyone to work on your car. I do all of my own work and have for years. I hope these suggestions are helping....

 

Some of the problems started when he installed my stereo (deck, 6x9s, 360w amp, 2 10s), like fuses blowing out. The previous owner said he never had a problem with it.

And yes he did install the power wire for the amp directly to the positive terminal of the battery. With a 200A fuse. The first fuse he had installed blew and made the power cable disconnect from the battery (wasnt as secure before tho). I just saw that the amp is recommended to use a 50a fuse, and it doesnt have an internal one. Im surprised it hasnt blown yet with such a high fuse.

There was already a wiring harness for an old deck a previous owner had installed. The old deck was working fine, I just upgraded it to a newer one, the power difference is minimal. The power cables they ran to the back were bad, so we replaced them. I dont think I replaced the ground wire though, and I do have a ground hum immediately when I turn on the deck.

Yeah I know the fan is supposed to come on with AC, but it wasnt running at all for a while. I finally got it to run with the AC on recently, so I plugged the fan switch back in (I had unplugged it a while ago and never replaced it). And now the fan comes on as soon as the car is on. Probably a bad fan switch and or connector. I have the parts. I have a 92 305 tbi, I only have one radiator cooling fan. They had a lot of variation in the cooling fans over the years. I got one from a 91 with the same engine, and the shrouding and the way the fan attached to it was just slightly different than mine.

That cranking problem is back too.. Turning the key to ON but not Start, and back off a few times helps it though. So that leads me to believe it could be something electronic with the fuel pump. The relay is 3 months old, and I swapped it with my other 3 month old fan relay, and the relays are not the problem.

No lights in the car are dimming, nor the headlights, or any other indication of electronic problems though, only the blowing fuses and random intermittant sensor problems. So I dont think its an alternator. The battery is only 6 months old, putting out 12.4V.

 

One other clue is that my idle will wobble around 500rpm after being warmed up. There is very little movement, but it goes slighty up and slightly down fairly fast. Engine has always been shaking at idle, it hasnt gotten any worse since the rpms started jiggling like that. Every once in a while, if I give it gas, let off, and then give it gas again, it will be sluggish to accelerate the second time. Does this indicate a bad fuel pressure regulator? Im still not sure how to check that, I was thinking of getting a fuel pressure tester today.

If I clear the engine by flooring the gas while cranking, then it'll start up on the next try every single time. And then after that, all I have to do is give it a little gas to start it every single time. Im thinking leaky injectors, because I was hitting the top of the injectors on accident with the air cleaner assembly. Plus that would explain why it just needs to sit for a while before the problem comes back, and why it smells extremely strong like fuel / gas in the engine bay more than anywhere else, and also why the IAC tries to suck in a lot of air when it starts up.

 

What have you done so far with the fuel pressure regulator?

 

Nothing.. Im not sure how to check it? Would the fuel pressure drop when turned off instead of maintaining it? I didnt get the pressure tester, and Im not sure exactly where you would hook it up? I see the fuel lines by the alternator, and read thats around where you should hook it up, but I dont quite understand where exactly you hook it up?

I took off topmost plate of the throttle body off, the part that holds the injectors and regulator in place.. I was flooded with fuel.. So Im thinking my fuel injectors are leaking.. I got everything dissassembled but I cant seem to take out the injectors. After the top plate is off, they should just turn with your hands right? Probably because theyre flooded they are stuck in there, they budged a tiny bit but wont come out.

 

Well my dumbass just tried to start it with the fuel injectors disconnected and top plate off.. It started up but fuel just started gushing out of that space in between the injectors, and kept coming out after I turned it off, took forever to stop. Now theres fuel all over the engine... Great.. I dont even wanna clean it cuz I dont wanna leave a soaked shop rag in my basement...

When i say the top cover / plate I mean this piece they pry off with a screwdriver. http://www.witchhunter.com/tbiremoval1.php Mine didnt need to be pried tho since it had been taken off before, I just had to unscrew it and take it off.

 

There's supposed to be fuel in there.

 

Damn.. Well something is causing the system to flood, because I can start it every time if I crank it with the pedal all the way down, and then start it, it starts right away.

I think Im just gonna take it to a shop, Im worried about the fuel on the engine bay too

 

sometimes it's better to save a grand and find a reliable/honest shop rather than royally screwing up your engine... and not knowing how to put it back together...

 

Ive paid a grand for a shop and they still werent a good shop.. Its hard to find a good mechanic. But I think I might have found one, and they work mostly with classics.

I hydrolocked the engine when all that fuel spilled out, it doesnt even crank. Im not sure what Im gonna do yet. Hopefully he can get it to run again. If not Ill probably just put it into storage until I have a garage. It would probably make more sense to sell it, and then buy one in better condition when I have a garage, but wheres the fun in that? Then again the body has surface rust, so I dont know if it would even be worth it. Ive had so many offers to buy the car as is, I might as well sell it and buy someone elses hard work

 

Pull the plugs & disable the ignition. Crank it or let it air dry. Do an oil change & add a couple oil drops to each cylinder.

 

sounds like you're conflicted kid...

personally i'd never have bought a TBI setup or anything that needs rust/body work but it's all a matter of how much time/money you want to put into the car. Now is the time that you either make the choice to do something about it (if you have the know-how, or the money), let it sit and waste away even more, or sell it to get some money back and save up for something better. IMHO I'd sell it... lol

 

I am conflicted haha. Thing is I got money.. I could just sell this one and buy a new one right now.. The problem is not having garage space to keep it in. Ive had enough of Worrying about the paint being exposed to the moisture, worrying about people vandalizing it, and worrying about car thieves. I probably will just sell it, and if I play my cards right and things go as planned, Ill still have plenty of money to buy another one in a half year or so when I have a nice garage thats real flat so I dont have to worry about scraping.

Yeah I messed up getting the tbi. This was my first sports car, the first car I really cared for and did a lot of work on. When I got it, I was thinking, yeah the tbi will be nice to be somewhat reliable and gas saving.. Plus I didnt have so much money back then. Life can sure change fast...and of course after about 6 months of reading ths site and working on it, I wanted a bigger engine haha

 

I bought my 87 IROC for 4,000 but should have paid only 3,000 (I've had the trans rebuilt and it's needed engine work; at least $5,000 into the car right now)... keep that in mind when you go looking. You can find one in great shape for $3,000-$4,000 but no matter what these cars always will need frequent maintenance/repairs, especially if you beat up on em'. Mine is in great shape though, no rust, no body work needed... etc... look at the pics