1995 GMC Jimmy

'95 Jimmy.4.3vortec CMFI Fuel Injection unit.

It will not start when cranking[intermittent], it has fuel pressure[60 lbs.] At injector, has spark, will start only when spraying Carb Cleaner into throttle plate, and then vehicle runs on its own. Ignition module and crank sensor have both been replaced

My theory is the Fuel isnt being delivered to cylinders in crank mode but will in run mode.
January 6, 2007.

Sorry for the late reply.

Usually with koeo, the fuel pressure is 60--66 psi. After it is running, it will run with less pressure. That spider fuel system is noted for problems. There have been some service bulletins about the fuel poppet valves sticking. Usually on first start-up of the day, the rest of the day, it may run fine. The cleaning procedure I've seen is a shop procedure.

Also, during cranking, your systems are getting battery voltage. Engine running, the systems get alternator voltage, there can be several volt difference.

Mar 15, 2015.