Have to bump throttle to keep running. Won't run at any steady RPM.

[PlayingWithTBI]

Nope. Using the throttle it won't maintain a constant RPM. Not 1K, not 3K, not at any RPM. I have to constantly work the throttle to keep it running, or it dies.

Let's see if we can stabilize it 1st before fine tuning min idle and IAC. The min idle is set 2 ways -

1) With IAC totally closed and setting idle ~100 RPM below target idle.

2) Adjust the min idle screw while watching the scanner to get IAC steps down to ~10.

 

[Hoot Gibson]

Am I missing something? The engine will not run at a constant speed. I don't have any fuel pressure. I don't understand how adjusting the idle, or the IAC, would have anything to do with that.

 

[PlayingWithTBI]

Am I missing something? The engine will not run at a constant speed. I don't have any fuel pressure.

No, you're on the right path, I was just saying, after you get that fixed, then worry about the idle.

 

[Hoot Gibson]

No, you're on the right path, I was just saying, after you get that fixed, then worry about the idle.

Whew! I was starting to get confused again. A state I'm all too familiar with.

 

[PlayingWithTBI]

Whew! I was starting to get confused again. A state I'm all too familiar with.

That's cool, I'm gonna throw another curve ball at you. a possible issue, although rare, is the FPR (Fuel Pressure Regulator) spring could be broken and allowing too much fuel to return to the tank. You can take it apart to see or, you can pinch off the return line and see what your pressure gauge says then.

 

[Hoot Gibson]

I thought about that, then forgot to do it. I'll check that before I get into the wiring checks.

Thanks!

That's cool, I'm gonna throw another curve ball at you. a possible issue, although rare, is the FPR (Fuel Pressure Regulator) spring could be broken and allowing too much fuel to return to the tank. You can take it apart to see or, you can pinch off the return line and see what your pressure gauge says then.

I thought about that, then forgot to do it. I'll check that before I get into the wiring checks.

Thanks!

 

[Hoot Gibson]

I think I can get to the wiring harness on the rail at the pump. Would it be a bad idea to put 12 volts to the grey wire and ground to the ground wire to see if the pump works?

Thanks!

 

[PlayingWithTBI]

Would it be a bad idea to put 12 volts to the grey wire and ground to the ground wire to see if the pump works?

You can, there's another way to test your fuel pump, put 12V to pin G on the OBDI connector. YMMV

You must be registered for see images attach

 

[PlayingWithTBI]

My post didn't post. Evidently it's waiting for a moderator's approval

Edit: now I can see it, can anyone else?

 

[Hoot Gibson]

I see it! That looks like it's a lot easier than worming around the wheel.

Thanks a bunch, I'll do that next good weather day I get! If that doesn't work, then I'll go to the dark side.