Engine running issues

Grommit327 · May 8, 2010

Checked both the IAC and EFI relay and both checked out. Haven't had a chance to check the TPS yet

The truck will start run to 1500rpms and die with no throttle input. Last night I was able to feather the throttle and keep it running for about 30 more seconds. It seems like it revs up when I let off the throttle while I am feathering it?

The fuel pressure thing has me wondering...I don't have a fuel pressure guage but could get a hold of one. I guess I need to read up on how to jump the relay

skinny_pedal · May 8, 2010

This might help

Notes

1. Remove circuit opening relay.

2. Inspect relay continuity.

o Using an ohmmeter, check that there is continuity between terminals ST and E1.
o If there is no continuity, replace the relay.
o Check that there is continuity between terminals +B and FC.
o If there is no continuity, replace the relay.
o Check that there is no continuity between terminals +B and FP.
o If there is continuity, replace the relay.

3. Inspect relay operation.

o Apply battery positive voltage across terminals ST and E1.
o Using an ohmmeter, check that there is continuity between terminals +B and FP.
o If there is no continuity, replace the relay.

Rix · May 8, 2010

Yeah, THAT sounds like a fuel problem.
Put a jumper wire (paper clip will work) between fp and +b terminals in the diag box.

Grommit327 · May 10, 2010

Alright after a Mothers day off of working on this I got back to it tonight. Tested the circuit opening relay and it tested out fine. Went to jumper the fuel pump and the diagnostic box doesn't have a connector for FP where it should be. Just a blank space :eeek:

I think the next step is to get a fuel pressure gauge on it and see what happens before/while it dies. I can hear the fuel pump run for about a second after it dies.

Thanks guys for the help so far

Rix · May 11, 2010

Check and make sure the ground bundle bolt on the intake is tight.
driver's side, right above the spark plug wire.

Grommit327 · May 11, 2010

Rix said:
Check and make sure the ground bundle bolt on the intake is tight.
driver's side, right above the spark plug wire.

Yep checked that one. Is there any other way to jumper the fuel pump besides the diagnostic box?

Rix · May 11, 2010

Not easily.
I have a scan tool that will do it at work.... but not at home.

FastEddy · May 11, 2010

test all your coil packs, and try hunting a vac leak with some carb clean

dumpsterdriver · May 19, 2010

i've had a similar problem. the culprit was the fuel pump itself. it sounded like it was working fine but would not maintain enough pressure. the symptoms sound exactly the same. definately try the fuel pressure gauuge next.

Grommit327 · May 24, 2010

dumpsterdriver said:
i've had a similar problem. the culprit was the fuel pump itself. it sounded like it was working fine but would not maintain enough pressure. the symptoms sound exactly the same. definately try the fuel pressure gauuge next.

I ordered a new fuel pump a few days before you posted this and just got it installed today...turned out to be the problem