02 Pioneer Edition Rough Idle

Kell · Aug 30, 2024

I have owned my Sport Trac for about five years. Just turned 100k then and now has 119k. I have fought a rough idle the whole time. I have tried everything. I have even switched parts from a donor vehicle without success. Seems to run pretty good although it is starting to be sluggish from a stop. I have new intake gaskets, valve cover gaskets, plugs, wires, injectors o2 sensors, cannot think what else right now but without success. Could the ECM cause this issue or maybe something internal? I get a Rich bank one and two along with cylinder five misfires. I used to have a small evap leak code but guess I have fixed during all the things I have done. Would anyone have any information that could lead me to the issue? I took the right o2 sensor off and put a gauge on it to check for clogged cat but doesn't seem to be the issue. Unless there is something I have overlooked.
Any help would be appreciated.

Todd Z · Aug 30, 2024

Fuel filter?
Air filter?
Dirty MAF?
Bad IAC motor?
When you did the intake did you do the injector seals ??
Ignition coil?

Check the PCV elbow UNDER the throttle body pass side, it cracks on the bottom and you can see it unless you take it off.

SwampTrac · Aug 30, 2024

I had this issue too. My problem was a dirty throttle body. If you havent already, clean the MAF sensor and throttle body. You can find both cleaners cheap at walmart. When you clean the throttle body, take it off the truck and clean the BACK. Thats the filthy part. Noticeable difference guaranteed!

Kell · Aug 30, 2024

Fuel filter? new

Air filter? new

Dirty MAF? cleaned, no change. Changed out to another one from a donor vehicle (cleaned it too)

Bad IAC motor? Cleaned and tried another from donor vehicle. It does open and close.

When you did the intake did you do the injector seals ?? did when I changed injectors. I actually took a garden hose and started the engine an ran wide open water possibly find a vac leak. No change in engine idle.

Ignition coil? Changed from donor vehicle... guess there could be two bad? Always have Cylinder 5 misfires. Many

Check the PCV elbow UNDER the throttle body pass side, it cracks on the bottom and you can see it unless you take it off. it was good but I did put a new one on it too.
I have a X tool scanner and it shows injectors operating fine. I need to get information on the short and long term fuel trims... don't know if my reading are low or high or ok.
Seem nothing changed the rough idle. Could there be an issue in the ECM to cause it?

I do appreciate your response! Anything else you can think of?

Kell · Aug 30, 2024

SwampTrac said:
I had this issue too. My problem was a dirty throttle body. If you havent already, clean the MAF sensor and throttle body. You can find both cleaners cheap at walmart. When you clean the throttle body, take it off the truck and clean the BACK. Thats the filthy part. Noticeable difference guaranteed!

I will look into that. Thanks !

Todd Z · Sep 3, 2024

OHM, the fuel injector, wires ?? within 20K mile. Check plug to see if its cracked.

Kell · Sep 11, 2024

After watching some YouTube video's I have found a noise coming out of where the air box is. Looks like they are saying it is the IAC. I have cleaned and tested... and also put another one on from a donor vehicle and it still is making the noise. When I unplug it, it does drop the idle and runs rough-er than normal but wonder if I may have an issue with the PCM? I have also found I still have the rough idle even when I remove the hose to the purge valve and plug up with finger on the intake side. The purge valve does not open like I saw on youtube after the engine gets to operating temperature but I can activate it with my scan tool and it does open. Anyone have any other ideas? I have used carb cleaner and also water from a hose thinking I would find a vacuum leak without success. I am at wits end!

Pat in RI · Sep 12, 2024

Hi Kell. If the evap purge valve and the canister are original to the Trac, I had to change both of mine to clear a code. The truck definitely idles and runs better. Here is a picture of the new canister purge valve in the completed set up before I put the system back into the rear of the truck.

ArtCall · Sep 13, 2024

Thanks for posting that, great info to know as I'm about to spend the winter refurbishing my 01 and I'm hoping to get all obscure items like that replaced.

Kell · Sep 14, 2024

Thanks... will check it out!!

Kell · Sep 19, 2024

I have been watching a lot of YouTube video's and actually it's all is swimming in my head to the point I don't know which end is up! Wouldn't mind taking somewhere to fix but think it would take many hours and you know hourly charges... but truthfully, I would like to find it myself - or with help online. Would give great satisfaction!! Think in the end it will be something easy and silly. I even saw a video on timing issues, valve adjustments but found they are not adjustable. I just don't want to keep feeding part to it and not the remedy. I do recall when I put new valve covers on it and remembered bank one head did look cleaner and newer than bank 2. Could there be a timing issue? Should I take off both again and check timing marks to make sure they are aligned as they should be? The previous owner passed away and gave to his daughter and she traded because with it being yellow, she didn't like everyone seeing where she was (that is the story I was told) so I don't think this was an issue just to get rid of it. Thanks for all your help!