Engine problems, rough idle,and stalling...

[jmw1856]

Having a couple issues and looking for a little help. My wife drives a 2003 Explorer with the 4.0 v6. Well recently it started idling really rough and stalling after a few minutes of idling. Its even really tough to get started. And when you hit the accelerator the engine bogs down and looses power like its being starved of fuel. I changed all spark plugs and ignition coil pack and it didn't fix the problem. I hooked the OBD meter up to it and it now pulls codes P2195, P2197. I have cleaned the mass airflow sensor and checked for a vacuum leak. No leak and the MAF cleaning didn't help either. Only thing I didn't do is replace the O2 sensors. I know my way around an engine decent enough to fix most things but by no means am I a mechanic and diagnosing problems aren't my strong suit, I hate it. Can anyone help me out a little tell me what the problem may be or something else to check? Someone to point me,in the right direction? I just hate dumping money into things that aren't fixing,the problem.

 

[Mustang Guy]

You'll need to start eliminating the easy and obvious possibilities such as vacuum leaks. I would check the PCV valve and hose for a vacuum leak. It's a little bit of a bear to get to but could likely be the culprit. It's on the drivers side rear up close against the firewall. I'd replace both the hose and PCV valve since they are 13 years old.
Have you removed and cleaned the IAC valve? If not I'd do that next.
The throttle position sensor could also cause these symptoms.
Just keep looking and thinking, you'll find it.

 

[jmw1856]

I'll take a look at the PCV valve. I did the cheap way and sprayed carb cleaner over the,vacuum lines,and listened for the idle to improve. But I may not have got the PCV valve and hose good. But I haven't tried,cleaning the IAC valve or checked the throttle positioning sensor. I will try that next. Figured I would cross all the cheaper things off the list first. Any specific way to clean the IAC valve?

 

[Mustang Guy]

I'll take a look at the PCV valve. I did the cheap way and sprayed carb cleaner over the,vacuum lines,and listened for the idle to improve. But I may not have got the PCV valve and hose good. But I haven't tried,cleaning the IAC valve or checked the throttle positioning sensor. I will try that next. Figured I would cross all the cheaper things off the list first. Any specific way to clean the IAC valve?

Carb cleaner really isn't very good at finding small vacuum leaks. I've found that visually inspecting hoses and fittings is a more accurate method.
For the IAC valve, disconnect the battery, take the engine cover off, unplug it and remove the two bolts. I use throttle body cleaner or MAF cleaner. You want to remove the carbon build up to allow the valve to move freely. Be careful to not damage the reuseable o-ring gasket.
If you end up replacing things like TPS, IAC, O2 Sensors and such stick with Motorcraft parts because the fit and work properly. I've found Amazon sells Motorcraft parts less the the junk Chinese knockoffs that Autozone or Advance Auto sells.

 

[jmw1856]

I will check it out tonight and see if either one will fix the issues. I really appreciate all the help!

 

[Stock94]

One more thing to check that I did not see mentioned: cleaning the throttle body. I did this once my 2003 4.6 v8 started stalling at stop signs and turns, and it seemed to do the trick.

 

[cancrusher187]

Carb cleaner really isn't very good at finding small vacuum leaks. I've found that visually inspecting hoses and fittings is a more accurate method.
For the IAC valve, disconnect the battery, take the engine cover off, unplug it and remove the two bolts. I use throttle body cleaner or MAF cleaner. You want to remove the carbon build up to allow the valve to move freely. Be careful to not damage the reuseable o-ring gasket.
If you end up replacing things like TPS, IAC, O2 Sensors and such stick with Motorcraft parts because the fit and work properly. I've found Amazon sells Motorcraft parts less the the junk Chinese knockoffs that Autozone or Advance Auto sells.

"For the IAC valve, disconnect the battery, take the engine cover off, unplug it and remove the two bolts. I use throttle body cleaner or MAF cleaner."

Brake cleaner. No diff other than the price. Been doing it like that for years.

 

[cancrusher187]

If I had to bet money on a guess? Lower intake gasket.