1990 Other GMC Models help us please

1990 GMC
Avatar
GUYLESURE123
  • MEMBER
  • 1 POST
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.
Jun 30, 2008 at 11:01 PM
Advertisement
Avatar
RASMATAZ
  • CAR REPAIR CONTRIBUTOR
  • 75,992 POSTS
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
Jun 30, 2008 at 11:03 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.