1990 chevy PU 5.7 k 2500 Runs then quits

Hello. Mom was driving her truck and it just quit running/stalled out as she was driving it. We towed it home and the next day it started and ran fine, but the check engine light was on and didn’t go off. She was driving it for a couple of days and it did it again. We originaly thought it was water in the cap because it was a rainy day when this happened the first time. Now, we have checked and it’s getting fuel and spark. When it’s cold it starts and when it warms up it dies. My oldest brother said this happened to him on his vehicle and he replaced the MOD sensor and this fixed his problem. We tried this and now it won’t start at all. We took in the VIN to make sure we were getting the right sensor. There are no adjustments on the MOD sensor. We checked/replaced the cap, wires, coil, MOD sensor and now the computer and it still won’t start. The brother that is working on it didn’t get to a place to check codes it might be throwing before he changed the computer.

Anyone out there have an issue like this. We are stumped.



Just another note on this. We also replaced the fuel pump fuse/relay.

FIgured it out. It was a bad Engine Coolant Temp sensor.

I must ask, what is a MOD sensor? You might as well not even pay attention to the codes associated with 1990 check engine lights, they will probably lead you the wrong way,(glad you got it going).

I was wondering the same thing as I read the post. Maybe MAP sensor? That will cause the engine to stall on a GM.

My bad. Brain fart, I meant MAP sensor. I work with so many acronyms that somtimes my brain jumbles them up.