96 Sonoma stalling Electrical Please help!

I have a 1996 GMC Sonoma 5 spd manual 2.2 liter 4 cyclinder two wheel drive. Last summer (2003) when I bought it, it ran fine, but when the cold weather came in October It started stalling and not starting sometimes. I drove it all last winter I just was stranded for a while and it would restart anywhere from 5 minutes to 1 hour, but everytime it would start. When spring came it ran perfect again, without doing anything to it. So here we are again, it is getting cold out again and it started doing this again. What happens is when I go to start the vehicle if the shift light does not blink the fuel pump is not running and it will not start, I have to turn the key back and forth until the shift light blinks again and the fuel pump then will be running and the car will start. This also happens sometimes when I am driving down the road it will just stall and I will have to wait, the check engine light and shift light blink on and off and I will stall out. It sounds like something is shorting out, but then it will go away and start back up anywhere from 5 minutes to an hour. I have put a new iginition switch in it and it still did not fix this. Once it starts doing this it seems to happen more frequently, once a week, twice a week, up to twice a day and I am just left stranded on the side of the road. Please help.

I also took the truck to a GMC dealship and they hooked it up to there computer and it showed no codes at all!

How many miles on your Sonoma?? If you have over 50,000 miles on it I would start with replacing the fuel filter. What I would also do is carry a spark plug tester and when you have this problem and it leaves you stranded and plug your tester in and see if you have spark, it might be difficult if you are by yourself.

I have a 96 2.2 and have never had this problem.

I have 86,000 miles on it and I just changed the fuel filter a couple of weeks ago and it still does this.

I have a 93 sonoma, and had a similar problem, but it was not seasonal. It came on quick, and sometimes would restart but most times not for a very long time. I changed the fuel filter, no help; changed the fuel relay, no help; changed the fuel pump; no help. Also the check engine light never came on. Ended up bringing it in, and it was the Ignition Control Module, $250 dollars of labor later it was fixed. I would suggest trying to change it yourself, alot cheaper

Check the connection at ignition switch under dash, seen it twice. May be loose

bprib, I could have written that post myself. I too have a 96 2.2 and it has done exactly what yours is doing. Unfortunately I have never found out what was wrong with mine because the problem was so intermittant. Mine also seemed to be weather related because it only did it in the winter months, nothing in the summer. I've spent the last year trying various forums and ideas to find out what the problem was and have found a couple or things that seem to come up over and over, most commonly I have found the the problem seems to lie in the ignition switch system. Now my truck hasn't stalled out in 10 months and the last thing I did to it was to wiggle around with the ignition switch wiring and connectors under the steering column. According to the last post a loose connection could be the problem, and that may have solved mine because like i said, I haven't had any stalling for the last 10 months. Last year around this time I could count on the truck stalling at least 2-3 times a week. I would try the ignition switch thing and see what happens. I you do find the solution please post it so I can check mine!

With the ignition switch on you should have power on the pink wire in the ignition harness(probably easier to check for 12v at gages, eng-1, or ecm 1 fuse, but I'm not sure where those fuses would be on the small trucks). My guess is that if those fuses don't have 12v when it stalls or doesn't want to start and the ignition switch wiring harness looks in good shape it would be a problem with the electrical part of the switch. You won't get a code for this, as far as the PCM is concerned the ignition switch is still off as the PCM gets voltage from the pink wire in the ignition harness, it does get constant power from another source to retain memory, but without 12v on the pink wire it won't fire the plugs, start the fuel pump, or fire injectors