1998 gmc 4.3 .Good spark , 61 lbs. fuel pressure , good compression. It only runs as long as you spray it or pour gas in intake. It acts as if the injectors aren't getting a signal. Any ideas. Thanks

check power at injectors, you should have batt. voltage on one wire. if ok check the other wire from pcm to injectors. let me know what you find. mws919

I have what they call the spider type injection system. I have power to 4 or more wires( I can't remember) in plug at the intake.I think they were orange. Could this be the crank shaft sensor?

install a fuel pressure gauge, run engin for a min. then shut it off and watch fuel pressure if it drops to 0 right away, it might be a broken line from fuel dist. to injector nozzel. very common. have you noticed any fuel smell in oil, also another ind. of bad cpi injector. let me know. mws919

The engine will not start. It has 61 lbs. while the engine cranks and hold it until gauge is released. Thanks Donnie...

post an email ad.. i'm going to put some diagrams togather for you.

dlt630@aol.com

sorry it took so long, was sick. check email and let me know. mws919

I bought an Actron OBD II Scanner today. The only thing it shows is a problem with the throttle position sensor. I didn't know a tps would keep it from starting. Thanks for all your help...

is the tps reading at closed throttle around 1/2 volt and incress smoothly up to about 4.5 volt at wide open throttle. it should be a steady voltage incress with out any glitches? or what is the code?

I'll check that voltage tomorrow. I'll keep you posted. The code is PO122. A Circuit Low Input

good deal, let me know

I took some time and rechecked a few things. Still has 61 lbs. fuel pressure,good spark, timing is good, throttle sensor reads correct voltage, and the injectors are getting a good signal at the negative wire(with the positive hot when the key is on) when the motor cranks. I'm stumped on this one. Fuel regulator maybe? It runs on starting fluid. Thanks....

pos. clogged nozzles?

A gallon of gas and a match might solve my problem.

changed my tps and still nothing. the only thing that happened was no more codes.i checked every sensor from top to bottom and they are all ok. 61 lbs. of fuel and good spark.. Started to roll up my power window and half way up it stoped. now when you push the window button the four ways flash. other than the not running part it's a nice van. by the way, it is for sale. cheap. real cheap.

pull the injector out leaving it connected and put each nozzle in a bottle , then crank it over, if nothing comes out and you are sure on your tests, replace the injector.

pull the injector out leaving it connected and put each nozzle in a bottle , then crank it over, if nothing comes out and you are sure on your tests, replace the injector.
the window is another story we'll read later, get it running frist.