[tickerpat]

Hey I have a 2004 XE 4X4 Crew and it dies when driving down the road or at idle, some times it will re start right away, some times I gotta sit for a while.

It has a brand new not re furbished, IPDM and ECU and all new relays and fuses.

other parts replaced are new spark plugs new fuel pump, and new crank sensor.

it has JBA long tube headers and Cajun B pipes, uprev tune and a no name intake.

it is going back in in Monday and gonna have compression and leak down tests done.

there is no check engine light and the only saved code is a multiple mis fires.

The mechanic and I are both completely stumped and have no clue where to go from here.



idle is set at about 600 is that too low? Could it be a bad coil pack?
or tuned too rich at low throttle position and at idle?

 

[LaxDfns15]

Is it P0300 for the code? Possible causes of that code are:

* Improper spark plug
* Insufficient compression
* Incorrect fuel pressure
* The injector circuit is open or shorted
* Fuel injectors may be faulty
* Intake air leak
* The ignition signal circuit is open or shorted
* Lack of fuel
* Drive plate or flywheel
* Front heated oxygen sensor may be faulty

I'd work on fixing that code before throwing more money at different issues.

 

[tickerpat]

it was throwing the P0507 code on the ECU, on the new it isnt saving any codes from the last time it was scanned. thanks for the input though LAX

 

[Walrus]

Compression and leak down have no bearing here.
Is the tail pipe rotted off? Because that will do it.
No codes is usually fuel not being delivered. Does it happen when low on fuel?

 

[tickerpat]

Exhaust is only about 2 years old,and in great shape

oddly enough it seems to be at its worst on the top end of the gas tank

 

[Grafton]

Could it be ... tuned too rich at low throttle position and at idle?

I had the same code P0300, rough idle, running really rough on the highway, exceptionally poor gas mileage. It turned out to be running too rich. Mine was the O2 sensors had fouled. The ecu was dumping so much fuel I was getting the intermittent misfire. Replaced them and got re-tuned. Now it's running very good, and mpg is back to 14 city.

Mine idles at 600 too.