2001 GM 4.6L starts, runs for 2 seconds, and then cuts out....... Help

[bob5326]

Hi Folks,
I'm new here, so first I want to say thanks for having me. Here is my tale of woe.... A friend of mine gave me a 2001 grand Marques, that supposedly needed e fuel pump for a 94 F-150 (I hate trucks, but they are useful) I replaced the fuel pump and sending unit, and it wouldn't start. Got a snap-on brick to check the codes, but he had killed the battery, and replaced it with a new one, but the codes, if there were any were gone. I sprayed a little starting fluid in the air filter and it sounded like it wanted to start, but wouldn't. Replaced the crank sensor and the cam sensor, now it starts, runs like it should for 1 to 2 seconds and then quits. It starts right up, and then dies. If I feather the gas, it will stay running for maybe 10 seconds, but it pisses and farts and then dies. I got a pending code which sent me to the IAC, which I did a pin point test on, and because I don't know much about 10,000 ohm testing, I replaced the IAC also, which changed nothing. I have the Ford repair service Manuals on CDs, but need help.

[SVT98t]

Check your grounds. Sometimes that will cause that.
Also, check for vacuum leaks.
And when was the last time the fuel filter was replaced?

-ryan s.

[bob5326]

thanks for the tips, I'll check those things and get back to you.........

[bob5326]

I'm back, spent the day checking grounds and tracing vacuum lines and found no problems. Of course with the engine not running, checking vacuum lines and leaks is a real pain. The fuel filter looks like it hasn't been in for very long, so I took it out and poured fuel thru it, and it runs right thru. I think I'm in the deep end of the pool now........... any help?

[sly]

other than vacuum lines... check all the sensors as best as you can. Try just unplugging them to see if it changes anything. Try unplugging the MAF first. if it runs (even if the idle is bouncing around), then that's probably the issue.

[jaywish]

Is there a way you can verify fuel pressure after it starts? Do you have a gauge?

[bob5326]

other than vacuum lines... check all the sensors as best as you can. Try just unplugging them to see if it changes anything. Try unplugging the MAF first. if it runs (even if the idle is bouncing around), then that's probably the issue.

I do believe you have solved my problem, or at least gotten me closer to it. I've been cleaning sensor plugs and connections and nothing changed. I killed the battery and don't have a charger, so I couldn't cranked the engine any more still I got it charged. So this morning, I grabbed a neighbor on his way to work for a jump. With the MAF unplugged, it started and ran longer then is has since I've owned the car. It didn't run great, but it did run, so I'm pleased. My next move it to pull the MAF sensor and clean the whole Air Intake System and give that a shot when the battery gets charged.
Slymer, you put a smile on my face today, first smile concerning that car in 3 or 4 months. Im hoping a good cleaning will help it out, but it doesn't look dirty.

[bob5326]

Is there a way you can verify fuel pressure after it starts? Do you have a gauge?

I borrowed a fuel pressure gauge, and had 35 psi with the key on, not running. I killed the battery and needed to charge it, so I returned it but can borrow it again. Slymer pointed me to the MAF, and that seems to be a problem. I'm gonna try to clean it, and will let you folks know how that goes.