I have a 1991 Camaro V6 3.1 MFI. It will cut out when ideling if ran long enough or if you rev it, it will cut out. I have replace the spark plugs and wires, cap and rotor. also fuel filter and the fuel pump. and nothing seems to be helping. I am starting to lean towards a sensor now. But I am not sure which, or if there is anything else it could be. Does anyone have any ideas?

 

Is it throwing any codes at all?
Any recent work done to it, aside from that maintenance stuff?

 

No work done lately and sometimes it throws a code right before it cuts out but when I go to check it, it dosent pull any codes except 12 which mean that mean the computer is working

 

It should store codes for a while. I think until you disco the battery for a while, or a specific amount of restarts. You waited until it flashed 12 twice then it just went back to twelve again?

I'm drawing a blank here, that's kind of a weird problem. Can you reproduce the problem at will or is it intermittent?
If you can reproduce it, you can try pulling a plug wire and watching it arc, then rev it by hand and if it cuts out, see if it's still sparking when it does. ie. narrow down if it's losing fuel or spark to make it cut out.
Losing spark should be a nice crisp shut off, but losing fuel it should sputter and die. So if it cuts out "cleanly" i'd say it's spark. I agree it's probably computer related, and that's about the point where i'd be bowing out of this thread...

 

yeah I know the codes should be in there but it keeps flashing 12. and the problem always happens I cant drive it right now because it wont stay on. The arch it fine and it sound like it is not getting gas but the gas it fine, like I said new fuel filter and pump and it has around 40 PSI for the fuel pressure. and everything seams to be fine on the electrical side and on the gas side. thats why I think it is a senor. one that would tell it how much gas. which pretty much every sensors does.

 

Have you checked your coil?

Is it a remote coil or a cap in coil?

Twice I've had a problem with HEI cap in coil style systems cutting out intermittently with no codes, sputters, farts, wont idle and just dies. The coil was "rolling" around in the mount and not making contact all the time.

Bad sensor wont cause the car to not run, a bad sensor will make it run like crap, but it will run. Should at least idle even with no TPS input.

 

I am not sure if I was clear but it runs for a minute and then chokes and cuts out because the way you are saying it makes it sound like it wont start. What did you do to solve your problem? the way your describing it sounds like it was the rotor that was rolling under the cap. Am I correct? or are you talking about the coil pack?

What do you mean by remote coil also what do you mean by cap in coil, I never heard these tearm used

for me the power goes from the ignition coil to the cap in rotor and distributes it to the spark plugs, I hope that helps.

 

So you have a wire running from your cap to your coil? That is remote coil.

Cap in coil=your ignition coil is part of your dist cap

 

yeah I have a remote coil then

 

Ok well if the car is suddenly dying it is either losing ignition or losing fuel.

When it dies just suddenly shut off or does it bog down, loose power and slowly die?

If it suddenly shuts off, you have an ignition problem. If it slowly dies you have a fuel delivery problem.

 

it bogs down but not a a constant rpms slowing down then cuts out it chokes like almost as you where gasping for air.

Edit: lopes is the word I was looking for

 

Update: I tested the TPS and everything seemed fine except something weird that happens with the ohms, at full throttle it jumps to lower number when it should get higher. But I don't think that is it because it happens at high throttles but I have the problem when it idols

 

does anybody have any ideas

 

did you test tps voltage or ohms?

ok so the car dies when loaded up (revved), or slowly dies at idle? Is that correct?

You have a fuel/air delivery problem. Like I said earlier I can't think of a single sensor that would cause the car not to run, since the car will run without any sensor or computer input at all (it runs like crap but will run). Have you checked all the vacuum lines? You said you had 40psi fuel pressure, where did you get that reading? IIRC the best place to take a fuel pressure reading is at the fuel rail.

Check your IAC valve. Check vac lines. Check for manifold/intake leaks.

 

I tested both

yes you are correct

I took the intake off to make sure that was the problem and it still did the same. and I took it of the nipple made for the pressure test straight from the fuel rail.

I will check the IAC in the morning

 

The IAC was fine any other ideas

 

uhm high-explosives and an insurance claim form? j/k

OK so we've checked fuel pressure, IAC, TPS ok...

You said you removed the intake manifold? ok maybe i misunderstood but how did that tell you if it was leaking? best thing is to spray a little carb cleaner or starting fluid around the base of the manifold while its running, if all of the sudden it surges you have a leak. I know I already asked but did you check all vacuum lines?

this is a 91? I cant remember if 91 models have a MAF or SD setup. Which is yours?

 

I ment I tool off the pipe to the air filter so it was getting air and the filter wasent cloged or blocked in any way. I will try the starter fluid at the base of the manifold and yes I checked vacum lines

It does not have a MAF those where on 89 and older cars

 

SD then; could be a bad MAP or Barometric sensor but you should get a code...

 

It not the ECM I replaced it and it still doers the same thing, ther was water in the tank but I got that out and it runs a little better and longer now but still cuts out and I get the 33 and 35 code one is for the IAC valve and the other is for the map sensor.

I tested the map sensor and that is good

How do you test the IAC valve

 

did you change the fuel filter after you cleaned the tank out? might be a good idea.

There is a tech article on testing and adjusting the IAC.

I would suggest also to disconnect ECM lead or battery to clear codes and then try again. See if you are getting same codes.

 

alright will do

 

I did change the fuel filter

The only article on a IAC is on adjusting it not testing it

 

there is a way to test IAC by resetting it...i forget exactly how, but a search should yeild results

did you check for vacuum leaks at the manifold?

 

Could be the Ignition module under the distributor cap.

read this
https://www.thirdgen.org/forums/tech...-firebird.html

-Kevin

 

If I am understanding you correctly, you say it runs fine when cold, but poorly when hot. Also, no check engine light. My best wild *** guess without seeing or hearing would be an ignition module.

 

well there is codes I pulled from the history but it is not a constant light:

33 (MAP sensor: Leaking or restricted vacuum hoses; poor electrical connection, open or short in the circuit; defective MAF sensor;defective ECM)

35 (Idle Speed control: TPS sticking or misadjusted; poor electrical connection, open or short in the circuit; defective IAC valve; defective ECM)

I tested the MAP sensor but turned out alright the wiring is good for the MAP too, don't have a MAF sensor, replaced the ECM and did the same, replace the TPS

thats why it leaves me with me try the IAC valve

but if it was the ignition module would it make a different spark?

 

nope I took it to autozone and got it tested and it was alright

 

I said the same thing above. See the problem with testing it at autozone is the module isnt at 200 degrees as it is under the hood. A lot happens with heat.