Hey guys! I hope someone has an answer for me on my surging issue. I have a 03 GT, I bought this car with a cold air intake and aftermarket throttle body. The MAF is stock. I believe the throttle body to be a 70mm and the MAF to be 65mm. Would this cause my surging at idle issue? Also, the air filter is not guarded in any way and was told that could also be an issue. Please help me! Thanks

 

1. Make sure all connections are sealed up properly, and there are no cracks in any of the hoses. Typical cause besides crap gumming up with works is a bad hose for the IAC.
2. Autozone - CRC Throttlebody and intake cleaner, and a bag of rags. CRC MAF contact cleaner while you're at it.
3. Yank negative battery terminal. To reset learned idle. As an 03, pretty sure your's operates the same as the S197s.
4. Pull TB, clean til you get all the crap out of it. Butterfly valves themselves have a special coating, which just spraying with the CRC TB cleaner will do nothing to, but don't go hog-wild on the valves themselves with the rag. It's the surrounding build-up around the valves that's the issue normally.
5. Pull MAF, spray all the openings you see liberally from a few angles and sides but hold it just by the electrical connection end, and touch nothing else on it with anything but the MAF contact cleaner spray.
6. Re-connect battery, start car, let idle for a few minutes without A/C, then put it on max and idle for a few minutes with it on. Checking for anything you might have missed or not properly tightened/put back on.

You will also likely get better(or more specific answers to your new edge) here.

Are you saying it has no shield around the CAI filter? They do serve a 2 part purpose, shielding from heat, and air turbulence. If there's turbulence the MAF can't keep up correctly. So if you still have issues after doing the above you may wish to buy some crappy CAI off craigslist/ebay for your newedge and just use the shield for a similar dimensioned intake filter. Might be cheaper and nicer just to have one made if you have a decent machine shop around.

 

Thanks for the response Wayne. I did all of the above as far as even removing the throttle body and cleaning it. Do you think the difference in the throttle body and MAF sensor could be the issue? Also, the air filter has no cage. It is pretty much wide open. It was like that when I bought it. I see other CAIs that have a partial cage, mine doesnt have that at all. Whats your thoughts?

 

Doubtful, but not certain.
http://www.stangnet.com/mustang-foru...to-get.825528/

This I already gave what little thought(s) I'm capable of, I'd say when you can do it, get a cage to fit it, getting a new tune/CAI, or get a cage from a similar one, or have one fabricated.

 

My 03 Ranger with the 4.0 does the same thing. It usually only does it at idle and it goes away once its warmed up, but then sometimes when I push the clutch in to cruise, the RPMs take about 10 seconds to drop down to idle speed. The only code I'm throwing is O2, so I'm thinking it may just be a case of the computer telling the truck that something is wrong and it should run ****ty. Long story short, have you ran it through a scanner?