Mechanics

WONT START

1998 GMC Jimmy

Engine Mechanical problem
1998 GMC Jimmy 6 cyl Four Wheel Drive Automatic 118256 miles

I have a 1998 GMC Jimmy 4.3 L. I went out to start it today and nothing. It cranks, tries to start, smoke comes pouring out of the air breather. It has 54 psi gas pressure, Every wire on the distributor sparks as well as the coil pack. I can get it to sputter when I pump the gas pedal slowly. I ran fine yesterday. I was thnking maybe the timing chain slipped a few teeth? HELP
Avatar
Tomsherri93
March 27, 2009.



Test the fuel pump pressure again that 54psi is way too low from the specification of 60-66psi

Rasmataz
Mar 27, 2009.
When I first turn the key on it is 60 psi, after a few seconds it drops down to 54-55 psi. I cant get a running pressure since the truck wont run.

Tiny
Tomsherri93
Mar 27, 2009.
Do you have spark? If not do below

No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, distributor pick-up coil, ignition control module, cam and crank sensors- Note: If it doesn't apply disregard it

Rasmataz
Mar 27, 2009.
There is spark at every plug. How do I test the cam and crank sensors?

Tiny
Tomsherri93
Mar 27, 2009.
You're getting spark disregard the cam and crank sensor. Do below and tell me what happened

Get a starting fluid/ether/better off gas in a spray bottle 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 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, distributor pick-up coil, ignition control module, cam and crank sensors- Note: If it doesn't apply disregard it

Fuel and spark okay-check the valve and ignition timing

Rasmataz
Mar 27, 2009.
We have tried all that you listed already. The truck wont even start when we put gasoline in the carb. We cant check the timing because the vehicle wont start. We are getting spark at all 6 spark plugs. We are at a loss.

Tiny
Tomsherri93
Mar 27, 2009.
Put engine no.1 piston on its compression stroke/TDC -remove the distributor cap is the rotor pointing to no.1 tower of the cap? If not-you need to redo the valve timing.

Rasmataz
Mar 28, 2009.