2005 Ford Explorer XLS 4.0 V6 issues

[James H White]

Rough idling, bad fuel mileage

 

[swshawaii]

Check engine light or stored trouble codes? Most larger auto parts stores will check for free. Call around.

If any, WRITE the p0 NUMBERS down and post them here.

OBD-II Diagnostic Trouble Codes (DTCs)

 

[Mike65]

Welcome James.

 

[James H White]

Welcome James.

Thanks Mike

 

[BrooklynBay]

Welcome to this forum! Did you clean the mass air flow sensor?

 

[James H White]

Yes, no difference

 

[MotoDan]

Check your fuel pressure. There's a Schrader valve at the end of the fuel rail where you can attach a gauge. Believe it should be approx 43 psi. If it's much higher than you probably have a shot fuel pressure regulator. Engine will run rich (rough idle, etc) and poor MPG. Easy check, cheap fix. Good luck!

 

[Merlin Tibbitts]

I had the same issue years ago on my 02 xls, no engine light the scanner readings were normal?!? I replaced my plugs and wires considering that they had over 50,000mi on them. Then I noticed that the rough idle issue seemed to happen on cold starts, she acted as if she wanted to stall out at times. MAF sensor seemed fine and considering that I change my air filter on every oil change(5,000mi) it had better been clean. At the time I had never flushed out my coolant and considering the miles the vehicle had and the role the engine coolant temp sensor plays I went ahead and replaced that as well. Although all of the above needed to be done and did improve the engine performance she still had the same rough idle issue?!? My next step was fuel pressure but before I went to test it I had to consider that the fuel filter had never been replaced on the vehicle. So I replaced the fuel filter and the other was seriously plugged up, thankfully the pressure checked out after the filter replacement...

The damn thing still had the dreaded rough idle?!?

The next thing and only other thing I had left was the IAC valve, I replaced it OEM of course and behold!!!

No more rough idle.

 

[swshawaii]

^ No external IAC used on 2004 Explorers and later with electronic throttle control. (Throttle-by-wire)

where is the Idle Air Control Valve on 2004 explorer
IAC location help!

 

[James H White]

Thanks Merle, I have been researching the IAC for my year Explorer, was told there is no IAC valve, that it was built in to the throttle body, which I already removed and cleaned, I went to Advance Auto, tech put code reader on pcm, said vehicle had gas vacuum leak, changed pcv valve, checked all hoses, I’ll try to smoke the system see if idle changes. By the way, this website is great, awesome support!

 

[James H White]

Thanks MotoDan, that will be my next check, really appreciate the support

 

[James H White]

Thanks Swshawaii, did get the code at Advance Auto, forget to write it down, but the tech said it was a general non specific code, and that I had a gas vacuum leak. I’m checking all the hoses, valves that might be the culprit.

 

[Merlin Tibbitts]

Thanks Merle, I have been researching the IAC for my year Explorer, was told there is no IAC valve, that it was built in to the throttle body, which I already removed and cleaned, I went to Advance Auto, tech put code reader on pcm, said vehicle had gas vacuum leak, changed pcv valve, checked all hoses, I’ll try to smoke the system see if idle changes. By the way, this website is great, awesome support!

Right on James, I do know that on my 02 4.0 the IAC is mounted to the throttle body. Based on my Explorer 2002- 2006 service manual I had assumed they all had the same setup.

Good luck.

Merlin

 

[Merlin Tibbitts]

^ No external IAC used on 2004 Explorers and later with electronic throttle control. (Throttle-by-wire)

where is the Idle Air Control Valve on 2004 explorer
IAC location help!

On mine it is mounted to the top of the throttle body.

 

[James H White]

Thanks for help, have a great holiday, stay healthy