96 Sonoma Stalling out

[York1]

Ok I have a 96 GMC Sonoma. 4.3 vortec, 130k miles.

For the last few months it has been stalling out at random times. It will happena couple times a day for 3 days straight then not stall for 2 weeks. When it dies it starts right back up 80% of the time. Some times it will run rough right before it stalls. Almost like the plugs had fouled out. It will also stall right after starting at times. A few times Ive had to let it sit for 3-5 minutes before it would start back.

Other than a clutch, water pump and brake booster I havent had any other major problems. In the last few months Ive replaced the following
plugs, wires, cap, rotor, O2 sensors, fuel pump relay, and Im probably forgetting a few other things too.
Ive checked the computer for codes and nothing comes up. The truck runs great aside from it stalling every now and then.

Ive talked to a few people and not gotten anywhere with this problem. I am hoping maybe one of y'all may have seen problems like this before. Any info would be appreciated.

[Philo]

This is exactly what happened to my '94 (S10) at 160k miles. It was the fuel pump. Sometimes it would run for days or weeks just fine, then give me problems for days. It would slow down and/or stall, then mostly start right up again. The problem with my pump was that the brushes wore away the segments in the pump until they were worn down to plastic (on one side). If the pump stopped with the brushes in just the right location there would be starting problems too. Changing the pump fixed it - no problems in a year.

[York1]

Ya thats what ive been leaning towards. Just didnt want to spend that kind of $$$ for a new fuel pump. I still cant believe its 240$

[York1]

Replaced the fuel pump this weekend and checked a few other things and it still stalls out. Seatbelt light and buzzer come on.
Im running out of ideas and money quick

[epiphaknee]

Your problem is interesting because you are not registering any error codes. I would agree that something fuel related might be causing this problem. In your maintenance items, you did not mention changing your fuel filter. I assume you did this when you changed out the fuel pump? Did you? On the Sonoma, these have to be changed about every 20k, or sooner, due to the "delicate" fuel pumps.

When you changed the fuel pump, you have to replace the strainer too. So, it's really the fuel pump, strainer and fuel filter.

The problem you describe sound like the EGR valve getting clogged but you would have had a code registered if that were the case. Like a 1406 code.

The other recurring problem with the Sonoma is the injectors clogging up. That could explain your symptoms too.

If you have not changed your fuel filter in a while I would certainly look there. They are cheap, compared to other repairs.

[York1]

It ended up being the ignition switch. Changed it out and havent had a problem.

[StinkyPew]

Originally Posted by York1

It ended up being the ignition switch. Changed it out and havent had a problem.

I had the same problem last week on my S15 Jimmy. I had previously changed the fuel pump and did the complete tune up you suggested. I ultimately discovered my problem by mistake. I was tinkering around under the hood with the engine running and simply touched the fuel system wire harness. The engine shut off just like it did on the road. After changing the harness it hasn't stalled yet. The stalling was a daily routine just how you described. Thought I would post incase somebody else is checking out this thread.

[gravyface]

Originally Posted by StinkyPew

I had the same problem last week on my S15 Jimmy. I had previously changed the fuel pump and did the complete tune up you suggested. I ultimately discovered my problem by mistake. I was tinkering around under the hood with the engine running and simply touched the fuel system wire harness. The engine shut off just like it did on the road. After changing the harness it hasn't stalled yet. The stalling was a daily routine just how you described. Thought I would post incase somebody else is checking out this thread.

Same symptoms with my 2.2 99 Sonoma. Well, I thought it was the TCC solenoids -- cost me 331 bucks for nothing. Its not the fuel filter either. Could it be the ignition switch or maybe the harness?

It starts right back up again, 90% of the time -- the other 10% usually takes a few minutes. Happens at low speeds/decceleration and stopping.

Ready to unload this lemon.