Does the gmc 1988 s15 have a crank case sensor

SOURCE: 1997 GMC Jimmy Crank Angle Sensor

it's at the front of the engine and below the and left of the front of the crank shaft.
dis-connect negative attery cable
dis-connect the electical connector to the sensor
un-bolt it and pull it out
reversr for installation

SOURCE: CRANKS BUT DOES NOT START

I had this problem with my 97 Jimmy. It is your ignition switch. The switch that touches the tumbler gets wore down. You'll have to tear the steering column apart to get to it and you will need a really small torx driver (not sure what size). Good Luck.

Dennis Mulford

• 1055 Answers
• Posted on Feb 01, 2009

SOURCE: 1997 GMC CRANKS NO START

check the ecm fuse and power wire from starter

SOURCE: gmc safari van cranks over, but will not fire up

I had the same problem with my 2000 GMC Safari two years ago....drove me CRAZY!

Sometimes it would start right up...other times it just would crank and not start.

It turned out to be a cracked coil....I found it by using a spray bottle with water in it, and "misting" the engine, at night....with the engine running. (On a night when it DID start!)

It took a while, but finally the hairline crack let in some water and the electrical short showed by a spark coming out of the coil.

I replaced the coil with a new one, and it has never "not started" since.

Evidently the coil cover gets brittle and develops small, hairline cracks due to heat from the engine.

Oh...by the way....I tested the coil it showed that it was fine!....but it took the "misting" at night...in the dark...to find the spark "leaking" out.

SOURCE: spinning will not crank

It's fairly common for the pickups in distributors to go bad.