1996 GMC Jimmy Won't start/When Raining

FRUSTRATED JIMMY

MEMBER
1996 GMC JIMMY
6 CYL
4WD
AUTOMATIC
196,000 MILES

Most of the time when it rains over night, the next morning it won't start. It turns over but won't catch. It only does it when it has rained during the night and the car is sitting over night. I have had it towed to a repair shop numerous times only to have it start for them. They have replaced the ignition module. I can hear the fuel pump running when I turn the key. The mechanic drilled a tiny hole in the carborator cover and told me to try squirting carb cleaner in it the next time it does it. I did but it didn't help at all, still won't even catch. Any ideas?

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

It turns over but won't catch. You need to confirm what's missing is it fuel or spark when it refuses to start

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine at least 3/16 away from ground -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, coil's resistances, distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it.