Mechanics

CRANKS BUT WILL NOT START

1998 GMC Jimmy

Electrical problem
1998 GMC Jimmy 6 cyl Four Wheel Drive Automatic 157000 miles

Engine cranks over good but will not start is not registering any default codes, If it does start will run for a few days then after sitting over night will not start again. Have replaced the cat converter as it was to small for the unit. Have tested the ECM and it is good. Thought about the coil pack and crank positioning sensor but do not want to throw parts at it, without registering a code where do I start
Avatar
Njmiller
July 15, 2010.




If it refuses to start don't wait for nothing- do below to find out if its fuel or spark problem that's causing it not to start-something has to give.

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine atleast 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, cap and rotor, distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it.

Tiny
Rasmataz
Jul 16, 2010.


AD