1989 S15 Jimmy
4WD
Manual transmission
2.8L
170,000 miles

I've been having starting issues in cold weather for a long time. Ran fine once it was warmed up. This year things took a turn when it started stalling. At first it was like it wasn't getting gas, or stopped getting gas. Then it would kick in. Found a vacuum leak and it seemed better for a few days. Then it just stopped while I was driving. Not putt-putt or studder, just quit. Got a MAP error but it checked out okay. Thought it was a clogged vacuum port on the throttle body so, ended up rerouting a vacuum line and it ran great. Really great. Until last Friday when it quit again. I'm at a loss so any help would be appreciated.

Parts thrown at it so far:
Plugs and wires
Idle air control
Coolant sensor
O2 sensor
MAP sensor and connector
Vacuum lines

Also, it's getting gas but now refuses to start at all.

 

Mine is doing the same thing.,
Plugs cap rotor , new distributor, map sensor, coil , new fuel pump, just loose power every now and then, rest of the time it runs good. , just going to keep on working on it and maybe some time it'll fix it, soon going to be a new truck, just keep replacing parts. Nobody has a definite answer to this.

 

I finally tracked it down to the ICM. Replaced it and it's been running great so far.

 

Thank you so much. I feel like I'm chasing ghost in this truck. Some good orderly direction is much needed here ✌️