20 Most Recent 1988 Chevrolet C3500 Questions & Answers

Check the wire that provides 12V to the coil, it should be switched by the ignition. It sounds like the switch is defective or the wire is connected to unswitched 12V

The idle is computer controlled and not adjustable. You may have a intake manifold vacuum leak that is the cause of the high idle.

How do you know it's actually started for gas? Are you sure it's actually starved for gas, and not just a bad o2 sensor? Are you having issues with it running properly?When is it running lean? WOT, idle, always? It's possible you have bad diaphrams and your secondaries aren't opening up, but hard to say without an actual description of the problem.

try this web sight.....good luck

http://www.manualsonline.com/?src=12022010

CALL THE CHEVY DEALER THEY WILL LOOK IT UP AND TELL YOU SAK FOR PARTS DEP MABEY GIVE SOME MORE TIPS

There is usually one located at the back of the motor just behind the intake manifold.

Do a major tune up,with air filter and fuel filter,cap and rotor ,and spark plugs,and maybe a pcv valve.This is most likely the problem,if not,then the distributor,or slack in the timing chain ,or ,a valve adjustment would be the cause,if this was helpful,please rate,thank you.

Your belt routing should be on a diagram on either the fan shroud, or the core support. However, this routing depends on whether or not your truck is equipped with a/c. Either way a belt routing diagram should not be difficult to locate.

if you have no fuel entering your injectors I would start by checking your filters then your fuel pump. Or a leak.

Usally the pump, which is in the fuel tank. Check the fuse and relay.

Have you tried to reset the computer,by disconnecting the negative cable on the battery?How about the speedo,is it reading correct?Is the truck burning rich?Disconnect the battery cable for about 25 seconds to rest the computer.Also have the fuel pump check to find out the fuel pressure.One more thing.Pull the egr valve,and look at it to see if it is closing off.It normally is closed with no vacuum.If it is stuck,it will cause the symptoms you are describing.I hope this was helpful,if so,please let us know,thank,you.

If the engine is fuel injected, the fuel filter will be on the drivers side frame back just before the fuel tank. Check the frame area under the cab and front part of the bed.

if the truck has a locking converter goin bad it will surge at steady speeds such as 55 mph the converter will lock and unlock causing you to feel an surging

code 12 is no tachometer or reference signal to computer.means a bad ignition module.replace it.also test coil make sure its not open or bad.

got a clutch pedal in there? If auto, it could be a 700r4 or some variation of that. You can likely get exact info from a dealer if you give them the vin #.