850 won't idle, quits and will run with gas pedal to the floor

[Dan Behr]

Hi all,

Here's the story:

1) Engine starts, runs for a short time, then quits.
2) After restarting, engine will not idle, but as the engine dies, if you mash the pedal to the floor, it will keep running. And, after you go to the floor, you can moderate it, so you can maintain about 3-4000 rpm.

3) If you let up on the pedal it'll quit.
4) Initial codes showed P1401 and P0115, fault in ECM, with a DTC of 1-1-2.
5) Replaced both computers. No improvement, BUT the error codes disappeared.
6) Tried another ignition module and coil. No results.
7) Fuel pressure and flow are just fine.

Any ideas?

Thanks....

 

[Guest]

Hi all,

Here's the story:

1) Engine starts, runs for a short time, then quits.
2) After restarting, engine will not idle, but as the engine dies, if you mash the pedal to the floor, it will keep running. And, after you go to the floor, you can moderate it, so you can maintain about 3-4000 rpm.

3) If you let up on the pedal it'll quit.
4) Initial codes showed P1401 and P0115, fault in ECM, with a DTC of 1-1-2.
5) Replaced both computers. No improvement, BUT the error codes disappeared.
6) Tried another ignition module and coil. No results.
7) Fuel pressure and flow are just fine.

Is it appearing to be running rich or lean, when it runs? Which engine too? Need to know if it uses MAP or AMM for load monitoring...

Tim..

 

[Dan Behr]

The engine is a non-turbo 5 cylinder (5254 I think) 20 valve.

Need to know if it uses MAP or AMM for load monitoring...

How can I determine this? Is there some kind of designation in or around the engine?

 

[Guest]

The engine is a non-turbo 5 cylinder (5254 I think) 20 valve.

How can I determine this? Is there some kind of designation in or around the engine?

No, its determined by the engine code. You have an AMM type system.

Also check that the main induction hose isnt split or the clamps are loose.

Tim..

 

[Dan Behr]

I did check the main induction hose and it did have a tear in it. For the time being, it's been duct taped, to seal the air leaks. However, the problem still persists. (You do mean the segmented 3-4" diameter air induction hose, like a vacuum cleaner hose, right?)

 

[Dan Behr]

I just talked to the mechanic regarding possible air leaks in the air induction hose and he said that he thought of that, so he disconnected the plug to the air mass meter. He said that in that case, the engine should have been able to continue idling, but it doesn't. What do you make of that?

 

[TOMSCORNER]

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