[Glen]

I read this article to today about cleaning the secondary ports below the manifold. And then in another thread some put a link to this article Replacing IMRC Actuator & Cleaning Secondary Intake Ports And Valves

This might do some good and I would consider doing it, but that is one heck of a lot of work for potentially no gain.

As some of you know I have had some power issues with my 98 Cobra. Plus it runs rough at idle and the idle is all over the board. I was going to put on new plug wires, replace the Air Intake Sensor, and Throttle Position Sensor this weekend. Then I was going to check the A/F ratio and see if there is anything else.

But this is mod that does not cost anything, only time....

What do you guys think? Has anyone done this?

[TobyBall]

I have noticed a rougher idle when the IMRC is bypassed and the longer runners are open full time. With your idle all over the board, that sounds like a different issue.

Would suggest trying the simplest and least expensive items first, but best is to get it to a trustworthy, competent technician familiar with that particular model of car... good luck finding one. I can recommend one up in Fontana who seems worthwhile, or contacts in your area for members of the local cobra club who may know someone, just PM me.

[97svt]

I have been looking into the IMRC delete. Lots of differing ideas on whether it is worth the work. But, I have a 97 Cobra that had the rough idle and wandering idle, I took off the IAC valve, cleaned it up, reinstalled it and now my idle is smooth, power seems more linear, used to get what felt like peaks and surges during hard acceleration.

[kulak]

My Cobra is the same way, rough idle, and noticeable power lunges during hard acceleration. The motor has less then 10K on it and it was doing this before and after the motor change. I am curious how or what you used to clean your IAC valve.

[97svt]

I was having the idle problem about five months ago, I did a search on one of the mustang sites (sorry can't remember which one) and someone there had a similar problem with neat pictures and everything. They recommended carburetor cleaner, but I used some electrical contact cleaner made by CRC called "Lectra Clean". I sprayed it full and shook it around, did that five or six times, took a cotton swab and cleaned as much junk out as I could, then sprayed a couple of shots of CRC "2-26" (an electrical lubricant). Made sure the part that is supposed to move, did, and the idle has been great since.