IMRC - intermittent?

[michael.lavander]

I should have asked the seller why the IMRC cover was off when I bought my car (plus a dozen other questions...C.org member). Anyway, I finally took my C-SVT up to triple digits - on a privately owned road, of course; mods...

In fifth, it took forever to hit 100mph; in fourth, it got to 110mph...I expected 125.

The IMRC is not pulling the secondaries open. I feel nothing around 3250 rpm, but maybe something at around 4k. I revved the engine in the driveway and the cable was pulling. The intake sound got deep a couple of times, but not everytime. The cable was pulling each time I got to higher rpm.

What are the common problems? Cable binding? My 1995 Escort GT pulls harder than this car over 4k rpm!!

[gorman]

I should have asked the seller why the IMRC cover was off when I bought my car (plus a dozen other questions...C.org member). Anyway, I finally took my C-SVT up to triple digits - on a privately owned road, of course; mods...

In fifth, it took forever to hit 100mph; in fourth, it got to 110mph...I expected 125.

The IMRC is not pulling the secondaries open. I feel nothing around 3250 rpm, but maybe something at around 4k. I revved the engine in the driveway and the cable was pulling. The intake sound got deep a couple of times, but not everytime. The cable was pulling each time I got to higher rpm.

What are the common problems? Cable binding? My 1995 Escort GT pulls harder than this car over 4k rpm!!

Hi Michael, the cover may have been taken off because the heat from exhaust and engine was affecting the imrc. You could try relocating it. ( search..it's been covered) The imrc operates at about 4k when you accelerate with part throttle and about 3400 when WOT. If you can't really feel any kick...you may need to clean your intake manifolds (search..been covered too). If you're still not happy after that lot...maybe upgrading intake and exhaust parts may get you closer to what you expect from your car. 110 to 120mph is about right for 4th gear with stock wheels and transmission...G.

[Tex]

It shouldn't take long to hit 100. If your IMRC was not working, you would know it because the car would basically have NO acceleration above 4000. Try opening the IMRC case, pulling out the circuit board and motor, and spray the motor out with CRC Electrical Cleaner, then let it dry and put it back together. If that doesn't work, it's time for a new IMRC. Pick up one at the local junkyard for $10-20, or from a CEG'r for $40-50 shipped. Before you do that, check the silver rod right under the LIM, near the throttlebody to make sure that the front bank of the secondaries didn't come undone.

[TRicker]

check the linkage for the IMRC. if the bracket connecting the two sets of butterflies isnt connected, that cable can pull on nothing all day long

[gooserex]

I had similar behavior and it turned out the grommet that attached the IMRC relay arm to the front secondaries (radiator side) was broken off, so when the IMRC would actuate it was only on half the cyl and gave a less then satisfactory burble, the interesting thing to note is that there was no cell code either.

good luck...

[DonKingKong]

I had similar behavior and it turned out the grommet that attached the IMRC relay arm to the front secondaries (radiator side) was broken off, so when the IMRC would actuate it was only on half the cyl and gave a less then satisfactory burble, the interesting thing to note is that there was no cell code either.

good luck...

That's exactly what happened to me. The engine had no low end power at all, but would pull normally above 3800rpm. I found that the butterfly valves for the front three cylinders were wide open the whole time.

[allstyle12]

Intermittent IMRC behavior points to a transistor on its way out.

A worn transistor operates normally at colder temperatures but can overheat and cause your secondaries not to open. After the car is nice and hot, open the hood and rev it up to see if the cable moves. If it doesn’t, that is your problem.

[CSVT#49]

Intermittent IMRC behavior points to a transistor on its way out.

Well I wouldn't say that is the case all of the time, because it sure wasn't in my case.

Early 98 Contours and a few mid 98 Contours have been known to have the same wiring harness failures as the recall for the pre98 Contiques (99M03 I believe?) In anycase for me I had the insulation breaking off of the wires going to my IMRC box. This causes some of the wires to short together intermittently, which causes my IMRC box to open/close at random. This was all burried under looming and was not visible until I took it off.

It wouldn't hurt to check your wiring going to the IRMC box as well for cracked/exposed wires.

[steelblueSE]

Intermittent IMRC behavior points to a transistor on its way out.

A worn transistor operates normally at colder temperatures but can overheat and cause your secondaries not to open. After the car is nice and hot, open the hood and rev it up to see if the cable moves. If it doesn’t, that is your problem.

Word. My IMRC used to work once or twice before the car warmed up then nothing. Didnt work at all over 80*. My solution was buying a brand new box after a failed transistor repair. I got it from Steve at Tousley Ford for 140 shipped to my door in 2 days. Haven't had a problem with it since. If you search, I did a nice write up on how to replace it.