20 Most Recent 1989 GMC S-15 Jimmy Questions & Answers

without looking at it i can only guess. Sounds like you need a new distributor cap and rotor arm. Hope this helps...

It looks to me you need a new or remanufactured cluster but ... find a wiring diagram for that cluster and with a test light checks the + wires(sometimes there is more than one +) and the ground on the wiring diagram. You will need to remove the cluster itself for the backprobe wire's test at the cluster terminals.

Without testing we'd only be guessing ! Do you want to replace a bunch of parts till the problem is fixed ? Hooking up a scanner an looking at engine management system sensor's (data ) inputs to the engine computer would be the first place to start. If you don't have the ability to do this , suggest you take it to a qualified repair shop . Or learn automotive Engine system diagnostic's . A lot of thing's could cause the problem your having . Do you know how to test automotive electrical an electronic system's ? Basic Ignition Description Operation and Testing any car Electric Testing Techniques You Need to Know ECM Inputs and Outputs Diagnosis

New parts can still be bad , check for cracks also check wires for white arc marks on each other or where they might contact a ground source .

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First check plug on actuator on front differential and be sure that plug is securely fastened to sensor and that plug has no rusted or corroded pins. Then test actuator and be sure it is operating properly. More than likely your four wheel drive actuator is malfunctioning.

Passenger side are even numbers.

They Screw Out Like a Bolt And In The Same Way

check ur crank positing sensor

These usually just screw out.Some will screw out and then have to be pulled slightly to release a lock tab if equipped.

I'm going to simply "spitball" an answer because i don't know WHY you think you need to change the oil pump. 1st, IF the oil pressure gauge isn't showing any pressure, or low pressure, AND there is no engine noises such as knocking or loud tapping, I would suspect a faulty oil pressure sending unit. IF there's a deep knocking sound then an oil pump isn't going to solve the problem. That is UNLESS it turns out to be what I ran across on a 1991 S10 4x4 with a 4.3. There was a "knocking" sound which I traced to the cover plate of the flywheel/flexplate. Turned out to have a cracked flexplate. Changed it and all was good. I have a 1985 GMC that showed low oil pressure, yet there was no noises coming from the engine to confirm low oil pressure. I changed the pressure sending unit and it fixed the problem of "low oil pressure". Now IF you're dead set on changing the oil pump, get ready because it isn't a 10 minute job. You'll more than likely have to at LEAST raise the engine somewhat as (I'm guessing it's 4x4) the oil pan has a deep sump area for the oil pick up. This is so the oil pan can be shallow in the front area to clear the front differential and cross frame area. Then you get to try to wiggle, twist, wiggle some more, the oil pan out from between the bottom of the engine/crankshaft, and the cross member of the frame AFTER removing all of the bolts that hold the oil pan in place. IF it were me, I'd be almost inclined to simply pull the engine, at least part way out of the truck, to gain better access to the pan. AND you wouldn't be fighting trying to keep the oil pan gasket in place while doing the wiggle/twist putting the pan back into place. Hope this helps.

the correct timing will be 12 degrees before TDC. It can be adjusted to 10 degrees but not over 12.

computer controls engine idle thru a idle air control valve, air control valve could be dirty or bad, recomend to clean valve and clean throttle body bore with cleaner and see if idle inproves

have you checked fuse at back of radio ?