rough idle/ surging

[Robbie Oh]

Was looking for some advice. Im trying to fix my 01 sport trac 4x4 for as cheap as possible. My engine has been having a rough idle/ surging issue for a while now and its time to finally remedy this issue. It is most noticable in drive while stopped at red lights and stop signs but also occurs while engine is in neutral or park. Ive been researching this issue online for about a week and hoping to get further direction on the issue. I currently do not have a check engine light on and the truck has about 163,000 miles other than this issue it is driving and operating fine. From what i have read the possible outcome is either a bad egr valve/ sensor, pvc elbow vaccuum hose, O2 sensor, intake gaskets, fuel filter, fuel injector, or even debris/ carbon in the throttle body. Can anyone help steer me in which direction to pursue first to fix the problem as least time consuming and as cheap as posssible. Im currently in the military so my time is limited to work on my truck. Any information would be greatly appreciated.



Thank you in advance,

Robbie.

 

[H D]

In about half an hour you can clean the throttle body, IAC motor and MAF sensor. There's projects in the projects section for these to the left. Even if these are not the ultimate source of your problem, it's good maintenance and will certainly help.



Also check your PCV elbow. Another common issue but will take a few more minutes than those above.



That's where I'd start.

 

[Robbie Oh]

I have already checked that elbow today and cleaned the throttle body about a week ago when installing a throttle body spacer but ill definetly try cleaning the iac and maf. Thanks Hugh.

 

[swshawaii]

Ditto on the IAC valve. An absolute priority if it's never been serviced @ 163K.

In addition to the MAF, check the air filter, PCV valve, and all vacuum hoses. GL

 

[Robbie Oh]

i checked the air filter las oil change about 3 weeks ago and thats still clean. and used a can of throttle body fluid around all the vaccuum hoses and did not hear any revs from the engine when i did that. so ill check the iac and maf first oppurtunity i get. Thanks swshawaii.

 

[swshawaii]

Did you forget spark plugs? Factory replacement interval is 100K, you're 63K over.

Use Motorcraft SP500 or Autolite 103 Series (Gap .054) Also check your plug wires.

 

[Robbie Oh]

yea plugs and wires were done last year.

 

[EddieS'04]

Throw the TB spacer in the trash. They only realy work on some carburated motors. The shouldnt sell them at all for port injection motors.

You may have a vacuum leak from the spacer.

In any case the spacer has increased nonthing, believe me many have tried it.