Truck: 93 351W 4x4 206000 miles. Always been extremly reliable till this problem.

Problem: When I turn the key on the fuel pump does not turn off after a second like it is supposed too.
Then when I crank it the truck runs like crap (not enough power to get up the hill out of the driveway), getting too much fuel. Fuel pressure is 40psi so Ok. Changed Fuel pressure Regulator anyway. Timing is right. 105-120 psi on all cylinders. All relays and fuses are good.

I can not check the codes. I put the jumper wire in and nothing, the Check engine light continues to burn. Any ideas on what to check now.

 

well, if the check engine light is on....get codes pulled. that will give you the best idea of what is happening. could be something simple like an o2 sensor or something more expensive like bad injectors.

 

If you cannot pull codes it sounds as if your computer may have went out.

 

If the fuel pump keeps runnining at startup KOEO then you have a leak somewhere in the fuel system. You already changed the regulator so that's not likely to be the problem. i'd bet on a leaky injector. Pull your plugs. One of them should be gas fouled. That will tell you which injector is bad.

 

If the fuel pump relay has been replaced with a known good one, you probably have a bad ECM. It's been my experience that when the fuel pump won't shut off, the MIL is on, you can't pull codes, and the relay and ignition switch are good, the ECM has failed.

FYI- GM ECM's have a similar effect when they fail; you can't pull any codes, and the fuel pump relay starts clattering like castanets. If that ever happens to you in a GM vehicle, it's a bad ECM.

 

Thanks guys, I will get another computer.

 

$45 for a junkyard computer and she is runnin like a champ.

 

Excellent! Thanks for the update.