Mechanics

MODELS HELP US PLEASE

1990 GMC Other

Electrical problem
1990 Other GMC Models V8 Four Wheel Drive Automatic

My 1990 suburban is not starting, it is not the battery, connections, axillary wire from the altinator or the starter. It starts occasionally with no problems but most of the time it will not start. It has power through the whole system, could it be the ignition? If you have any other advice that would be great.
Avatar
Guylesure123
June 30, 2008.




If the engine's condition is in tip top shape-do below to determine if its fuel or spark problem that's if its cranking over and refuses to start

Get a carb cleaner and spray into the carb or the throttle body on an EFI. Did it start and die? If not disconnect a sparkplug wire or 2 and ground it to the engine -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel problem, check the fuel pressure to rule out the 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, distributor pick-up coil, ignition control module, cam and crank sensors-

If both fuel and spark is present-check the valve and ignition timing, this will lead you to problems with compression and valves opening and closing at the wrong time

Tiny
Rasmataz
Jun 30, 2008.


AD