timespy

I have a 91 camaro rs convertible with 305 tbi motor in it. It is mildly modified with an underdrive pulley system, 3 1/2" exhaust, 225 fuel pump, new fuel sending unit, 55lb injectors, 3/4" aluminum manifold riser, double row timing set with a 3* advance, big *** open element air cleaner, and a few other small mods.

That should say enough about the motor to possibly help someone diagnose my problem..... The car wont stay running. Let me rephrase that..the car runs great..fast, hooks nice, and pulls high 13's in the 1/4 mile. The issue is that the car will start, run fine for 30 seconds or so, then shut down like you turned the key to off. Starts right back up every time, but will die off after 15 seconds or so. this can happen anywhere from 3-5 times before it will stay running for good. After a couple hours it will sometime just shut off again..always at the worst time of course ( making a turn in an intersection during rush hour).

I have replaced the ecu, thermostat, distributor, plugs, wires, coil, fuel pump relay..almost everything that would or could cause this problem. I am stumped on this one, I had it in a shop, and the guy couldnt find a single thing wrong with the car..no codes, no nothing. Said it was in perfect tune.
Obviously there is something going on here, and i really hope someone here may steer me in the right direction. I though perhaps there may be crap in the fuel tank getting sucked up and blocking the strainer, and falling back down when it shuts off, but that seems a bit off the mark i think because it doesnt happen at highway speeds very often. It also seems to happen as the weather gets colder, which leads me to think there must be an air temp sensor going haywire somewhere. Also thought about the o2 sensor, would a heated 2 wire sensor somehow stop this?

Please..any help or advice will be greatly appreciated. My wife is pushing me to get rid of the car for this sole reason, and i just cant bring myself to do it.

Shadow Z

iTrader: (2)

Did you check your turning signal fluid, and brake light oil?

Seriously though, this would stump me too. I'm thinking it's a fuel starvation problem, sounds like that kind of problem.

timespy

Yea, I checked all of those. I even thought the muffler bearings were bad, but i just had them replaced.

raptor80dad

I would check all grounds to make sure they are clean and tight.Get a schematic for your car to make sure you check them all.Just a thought.

closer

I had a neighbor having the same problem with his truck. I changed the coolant temp sensor that goes to the computer. And it fixed his truck. Do you have a check engine light on? His truck also ran pig rich....
Also when it dies... does it just slowly die? or just like you turned it off?

timespy

I have changed the tep sensor, and the ecu. Yes the car just shuts off as if you turned the key, no bogging down, just shuts off. No sputter, no nothing. Im gonna hook up a laptop to it, and see what if anything winaldl shows. Still hoping for some hel phere..Keep it coming.

Zwrench

Did the shop you took it to put a fuel pressure gauge on it?

I ask that because I had a fuel pressure regulator go out on me that caused the same symptoms you describe. I replaced it and haven't had a problem since.

Just something else to check! Good luck and let us know what you find.

chas0218

could it be a sign of the fuel pump/connections in the tank? I was thinking the sending unit might be going. You leaking any gas from the car? Maybe loosing prime in the fuel system? Just a guess so dont flame me too hard.

bluegrassz

iTrader: (3)

What about the oil pressure sending unit. Maybe letting the car prime, then not showing oil pressure correctly then turning the pump off.

camaronewbie

Also try an ignition module - it's in the distributor under the rotor.

srosscamaro@aol

i think its deffinitly a fuel problem sound like u have a clogged fuel line or bad fuel filter remove the filter and the line at the throttle body and blow it out with a compresser

Air_Adam

When they are starting to die, they act just as you described once everything warms up - untill it just dies completely.

Pocket

iTrader: (24)

Heatsoak isnt very nice to old dist modules. Luckily most part stores test them for free

Also test your coil once it gets hot. They act similar

Motopsyco

its a theory but happened to my 91 I used to have, turned out the started was bad, actually just a wierd kinda bad, it would somehow cut off the electricity and kill the engine, couldnt figure out what the problem was til the starter completely died a month later, changed it and the car didnt randomly die ever again. Probably nothing to do with it, but something to check out just in case, sometimes the stupidest things can leave you guessing at all kinds of stuff

--Stormr

sonjaab

Shuts off with no warning then restarts? Stock delco dist. set up?

X2 for the ignition module.............Cheap fix