*Warning* on cleaning the IMRCs

[shelbygt]

So, I ended up cleaning my 98's IMRCs in the hopes to fix my car's sputtering issues which turned out to be defective new Ford plug wires. After spraying the plates down with carburetor cleaner, the carbon buildup seeped into the bores around the shafts and caused the plates to no longer move freely. I ended up removing the plates and shafts to clean out the carbon gum and carefully reassembled them. They moved freely and were now spotless. After reassembling the intake, I now have an idle issue 98 Cobra idle when moving - YouTube

So I went through replacing and testing everything associated with the idle (IAC, MAF, TPS, EGR, etc.) and ended up taking it back in to the shop to run tests that I couldn't. He called me in and did the smoke test (which I also did with a cigar and a hose) in front of me that revealed a massive leak that had smoke pouring out of the front part of the IMRC where the shaft meets the outer part of the plate. I guess either the carb cleaner damaged the seal or the carbon was making a seal in the bore and I cleaned it off, but anyway, it caused the leak.

I hadn't planned to delete them because of the 50/50 opinions as to whether it is beneficial to a N/A motor to do so, but I have no choice now but to delete them.
The mechanic (a former 97 Cobra owner who also deleted his) is going to do it and said he can reprogram the computer to turn off the IMRCs for 100 bucks.

 

[NVRL8TE]

$100 bucks is a good deal.

Do it.

Thanks for the warning. Owe ya one...

 

[shelbygt]

$100 bucks is a good deal.

The 100 bucks was only to reprogram the computer. But it shouldn't too bad, as the owner of the shop who is doing the work is a friend of my father in law. :rolling:
Otherwise, I would just take the car home and do it myself.

 

[NVRL8TE]

Okay I get it.

Still couldn't hurt your wallet too much.

 

[98$vt]

The 100 bucks was only to reprogram the computer. But it shouldn't too bad, as the owner of the shop who is doing the work is a friend of my father in law. :rolling:
Otherwise, I would just take the car home and do it myself.

What is he re-programming your computer to do exactly?

If you had the intake off to clean them.. Why didnt you take the IMRCs off an clean them by hand?

 

[shelbygt]

What is he re-programming your computer to do exactly?


If you had the intake off to clean them.. Why didnt you take the IMRCs off an clean them by hand?

He said the 100 is for the custom tune or flash programming that will be loaded onto the PCM.
I did have the IMRCs completely apart and cleaned them by hand.

 

[98$vt]

He said the 100 is for the custom tune or flash programming that will be loaded onto the PCM.
I did have the IMRCs completely apart and cleaned them by hand.

Oh gotcha
Well I don't have IMRCs and the controller is gone and all disconnected, I am also un-tuned and have no handheld.. Could be dumb luck but my car runs great and has no check engine light from it

 

[shelbygt]

Oh gotcha
Well I don't have IMRCs and the controller is gone and all disconnected, I am also un-tuned and have no handheld.. Could be dumb luck but my car runs great and has no check engine light from it

Really? Everything I have read said that if the PCM does not get a signal that the IMRCs are opening and closing it will throw a CEL, unless you get a tune, put in a homemade relay to fool the PCM, or rig up the spring with the control box still hooked up to make the PCM think that the IMRCs are still there and working correctly.
Also if I understand correctly, the addition air flow from the deletes will need to be tuned into the PCM for optimal performance.

What gears are you running and are you happy with the deletes?

 

[98$vt]

Really? Everything I have read said that if the PCM does not get a signal that the IMRCs are opening and closing it will throw a CEL, unless you get a tune, put in a homemade relay to fool the PCM, or rig up the spring with the control box still hooked up to make the PCM think that the IMRCs are still there and working correctly.
Also if I understand correctly, the addition air flow from the deletes will need to be tuned into the PCM for optimal performance.

What gears are you running and are you happy with the deletes?

Like I said could just be my dumb luck haha
I'm running 4.10s and I would never look back to the IMRC.
My car doesn't drive out of the ordinary an doesn't bogg or anything, power band is strong all the way thru

 

[shelbygt]

Like I said could just be my dumb luck haha
I'm running 4.10s and I would never look back to the IMRC.
My car doesn't drive out of the ordinary an doesn't bogg or anything, power band is strong all the way thru

Good to hear, I have 4.30s and just didn't want to lose the "take off, pinned in the seat" feel. :rockon:
Do you know if the IMRC controller is still plugged in under the intake?

 

[Noreast]

You take the whole thing out. I'm running MMR IMRC deletes with stock 327s and I didn't notice any loss at all just more pull up top if anything.

 

[Chris.94GT]

Why not just replace the bearings? Bearings are usually pretty cheap.

 

[shelbygt]

Why not just replace the bearings? Bearings are usually pretty cheap.

That was an option, problem is where to get them to be an exact fit. Plus if the actual plastic of the plate is worn around the bearing, it will still leak with a new bearing.

 

[98$vt]

Good to hear, I have 4.30s and just didn't want to lose the "take off, pinned in the seat" feel. :rockon:
Do you know if the IMRC controller is still plugged in under the intake?

No it's all gone

 

[shelbygt]

*Update*

So after ordering new gaskets and planning to have the IMRCs converted to deletes, I got the call today that the car was ready to be picked up. It turns out that there are 2 small rubber o-rings on each end of the shaft and mine were brittle and cracked causing the leak and idle problem.
The shop replaced the o-rings and the car runs and idles perfectly now.

Just a heads up to be aware of these o-rings when cleaning the IMRCs.

 

[SVT CAMR]

great info. nice follow uo too.