Mechanics

CHEVY 89 Z-71 SHAKEY STARTS..

1989 Chevrolet Truck

Engine Performance problem
1989 Chevy Truck V8 Four Wheel Drive Automatic 189k miles

Truck started shaking and cut off. Cranked and shook for another few seconds and cut off again. Turns over, but will not start. Diesels. But when it starts it runs like new.? Will continue to run with out any hesitation. The truck will even restart with in several (warmed up) min of running. But in the morning same old chug chug and die. It take atleast 10 min of cranking to get it to start. This is the first time in 20yrs it has done this. At 189k it has always starting with out any trouble at all.
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Marison rice
June 8, 2010.



If it is running rough, shaking, and dieseling, it could be a symptom of low fuel pressure. It does not take much for this vehicle, spec is 9-13 psi. One concern is how the maintenance has been. Has the fuel filter been serviced regularly, or has the original gone 189k miles. I would start by considering what has been done for maintenance, checking fuel pressue, and if below spec replacing pump and filter. One other consideration is tune up parts, specifically coil and coil wire. Low spark output on adequate fuel pressure can give you somewhat of the same symptoms.

Factoryjack
Jun 8, 2010.
Thank you so much for your answer.
I have check the fuel pressure and it is good. I changed the fuel filter and pump 10k miles ago. If and when the truck starts it runs like new. The injectors have never been replaced nor the fuel pressure regulator. Would you suggest starting there? The plus and wire have about 40k on them.

Marison

Tiny
Marison rice
Jun 9, 2010.
On a TBI system, injector and regulator problems are relatively rare, especially intermittent type problems. There is also a possibility of contaminants in the fuel, perhaps some water. What will happen is, as the vehicle sits, the water gathers and rests in the lowest part of the tank. In motion the water is mixed and the molecules are smaller, and passing them may be less noticeable. It may be advised to take a fuel sample in a clear container and let it sit to see if any moisture is present. Has this concern occurred over more than one tank of fuel?

Factoryjack
Jun 9, 2010.
Now that you mention it. No It could be bad gas.
I know that I am getting plenty of pressure. I will check that next. That could explain the fact when it is moving it runs great. This truck has not been used alot with in the few months. It does sit for week on end. I sure hope that it is the gas. That will be an easy fix.

Thanks

Tiny
Marison rice
Jun 10, 2010.
Let's hope.

Factoryjack
Jun 10, 2010.