Mechanics

CHEVY 3.1 STARTS, BUT DIES IMMEDIATELY.

1991 Chevrolet Lumina • 20,000 miles

I have a 1991 Lumina 3.1 V6. Car Will start while turning it over, but dies immediately. Every now and then you get lucky, and it will idle, but dies when you give it gas. Then once it ran great for 2-3 minutes, revved great, idled great, but that didnt last long.

I have replaced the following:
Fuel pump, filter, Crank Sensor, Bought a used computer at a local parts yard. I was told injectors were replaced approximately 2 years ago.

I know it is getting fuel to the rail, because when I took the lines off, fuel came out. I did notice the MAP Sensor vacuum line was broke. Shouldnt it still run better than it is now, even with that small leak?
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Braetz
December 15, 2011.



The MAP can cause many different problems. However, are you sure you are getting fuel pressure that is within the manufacturer's specs? Can you keep it running with starting fluid?

Fix the vacuum leak and clean out the idle air control valve and EGR valve and test the TPS sensor-also check the fuel pressure with a gauge if its within specs

Rasmataz
Dec 15, 2011.
That is a good recommendation. The manifold absolute pressure sensor can cause the engine to die out. What raz mentioned will cover all the bases.

Let us know what you find.

Thanks, I wont be able to get to it, til friday as I work tomorrow and I work 24 hour shifts. Thanks. Will let you know.

Tiny
Braetz
Dec 15, 2011.
Wow, 24 hr shifts. That would kill me. Let us know what you find.

So, I have fixed the vacuum leak on the MAP sensor, cleaned Idle Air Control Valve, Cleaned Throttle Positioning Sensor. The Car now runs seemingly fine when cold, but when it warms up, after running approximately 5-10 minutes, it shuts off. Then it starts and dies immediately. Will try to run while spraying starting fluid. I have read on other sites that this is often a bad fuel injector, causing the others to fail during "open loop". If this is the case, how do I test an injector? Or, do you think it may be something else? Thanks. I was to the point of taking it to the scrapyard, as I only paid 250.00 for the car. But if this might be the problem, its a fairly easy fix.

Tiny
Braetz
Dec 17, 2011.
When this happens, have you checked fuel pump pressure?

I have no fuel pressure gauge, but what I have done is pushed in on the pressure tester, on the fuel rail and fuel sprays out with what seems to be plenty enough pressure.

Tiny
Braetz
Dec 17, 2011.
Is there any play in the key?

I dont believe so, no more than normal. Afterall, it is a 20 year old car lol. But it isnt loose by no means.

Tiny
Braetz
Dec 17, 2011.
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