20 Most Recent 1988 GMC C1500 Questions & Answers

You did not say what the mileage is. Judging from the age, I would say it is pretty high. The issue most likely related to timing. The shaft that turns the distributors rotor cap has bushings on it and it also is driven by gears inside the engine. They wear out and the timing becomes off. Also you can get a lot of wear on the timing chain and gears at that age.

1988 GMC C1500 | Answered on Aug 03, 2017

Do a compression test. The pistons and rings may not seal enough anymore. Try push-starting it in 2nd gear. When you push it ,it will turn the engine faster and build up more compression, enabling combustion to take place. Aslso check if the fuel pressure regulator is not leaking through the vacuum hose, causing it to flood.

1988 GMC C1500 | Answered on Apr 30, 2017

Use a gage and check proper fuel pressure. With tbi fuel injection, the fuel pressure is 9--13 psi. I have seen fuel injector spray pattern that looked good to me, but, the fuel pressure was half of what it should have been. 5 psi may show a good spray pattern, but, it won't start and run a v8. In my opinion.
Any applicable trouble codes? Your obd1, you should be able to check some codes yourself, if there are any.

1988 GMC C1500 | Answered on Apr 21, 2017

If you have a coil pack on that .You have a crankshaft censer.Change the crank censer.

1988 GMC C1500 | Answered on May 05, 2016

Air, fuel, spark. Each will have to be tested. Sometimes when you think the battery is good, it's really not. It can have some juice in it but the CCA (cold cranking amps) is really what you need to have at near full capacity. Are the battery cables in good shape and not just at the connectors to the battery. They can corrode (especially the positive red cable) at both ends (at the starter (red) and at the ground (black).
Did you recently work on the truck and replace something? Retrace your steps if so.
Fuel filter not clogged (recently replaced) and fresh fuel in tank?
Pair filter in place and not clogged?

1988 GMC C1500 | Answered on Nov 24, 2014

that is obviously the correct way , you must have had the engine 180 degrees out when you started , did you not lock down the cams etc ?

1988 GMC C1500 | Answered on Jul 18, 2014

Check it in Park and Neutral position. Put a test light on small wire at the starter and see if it lights when the key is turned to start. If no light, the wire is burned. (fusible link) test further up the wire until it lights to verify

1988 GMC C1500 | Answered on Jan 01, 2014


1988 GMC C1500 | Answered on Nov 15, 2013

It sounds like a problem in the main harness.
The brake lights are on the same circuit as the turn signals and hazards, but the parking lights and backup lights are on different ones. So the only thing connecting all three is the ground circuit. The tail lights use a printed circuit board in the lamp assembly that could have problems, but not usually for both sides at the same time.
All you can do is use a test light or meter and trace the circuits from the light bulbs back to the firewall and see where the power is stopping.

1988 GMC C1500 | Answered on Jun 24, 2013

remove, clean up and resilicone it and install

1988 GMC C1500 | Answered on Jan 18, 2013

Check signal to right injector with a noid light. It is probably not getting a signal.

1988 GMC C1500 | Answered on Aug 08, 2012

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