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Discussion Starter #1
Is there any point to keeping the IMRCs in a Mark VIII if you are running a 3400 stall? It just seems with the cleaning they require, and that they really aren't doing anything with that high of a stall, you'd be better off just deleting them.
 

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Discussion Starter #3
Everyone I know that has a Mark or a 96-98 Cobra has to clean their IMRCs every 6 months or so, or else they'll have a funky idle. I've heard cars without EGR don't have that problem though.
 

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The Parts Guy
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Cool, I shouldn't have that problem since I'm not running an EGR on my DOHC (and the engine is brand new, so they should be clean right now). How do they clean them, anyway?

-Rod
 

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Discussion Starter #7
That's what I would imagine. Don't really know, I've never had a Mark VIII before, this is a first for me, but I have a couple friends who always complain about theirs. One said it is the exhaust from the EGR that makes them nasty.
 

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The Parts Guy
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SloMo228 said:
At what RPM do the IMRC's open?
Right around 3000 rpm.

-Rod
 

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Here's my take on the ole "cleaning of the IMRC's" issue:

Keep your foot in it! From what I've researched what happens is that the oil from the PCV system and the "goo" from the EGR system just puddles and gums up on the IMRC's if you have a driving style that normally keeps them closed. I.e. a lot of people driving Mark's and Continentals with the DOHC (as much as I hate to say it... grandma/pa's).

If your driving style "uses" them a lot, then it is probably ok. My 97 threw a "stuck IMRC" code a while back and I was able to clear it by running a can of SeaFoam through it. The problem is that you can't open the IMRC's while in park (at least on my 97, they don't open no matter what rpm you're at if you're in park)

And to the original question: IMRC's wired with high stall... I would say yes. Your higher stall converter is really only "used" at the initial "flash" from a dead stop. Once you're on the road, it really doesn't matter that much (or at least I don't think so).

So unless you want to get rid of your low end torque while just "tooling around the area", I would recommend making them functional.

Just my .02. :thumbsup:
 

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I just got done pulling my intake and figured I would clean my IMRCs since I have heard so much about them getting gummed up. Well when I got my intake pulled my IMRCs were not gummed up as people would claim. They had very little deposits on them and that's with 3 years of driving.

As for keeping the IMRCs with a 3400 stall, yes keep them. Just because you have a 3400 stall doesn't mean that that car isn't going to move until you reach that rpm. The car will drive almost normal with the exception of it being a little sluggish like you are starting out in 2nd gear. If you remove the IMRCs that sluggishness will only get worse since you will no longer have any torque to get the car moving and thus will have to give it an extra amount of throttle.

I have a 3600 stall with mine and during normal driving the IMRCs keep it driveable in traffic.

They are factory set to open at 3000 +/- 100 rpm.
 

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I could be wrong, but it sounds like a little bit of a catch 22...without the IMRC's, your input torque will be lower, and it won't stall the converter as much anyway. Regardless, driving around town at partial throttle will not cause your 3,400 stall converter to flash to 3,400. Remember, stall is a function of input torque, so at part throttle when your input torque is low, so is your stall. The IMRC's should make it much more drivable around town. But hey, that's just my opinion, I could be wrong...(Dennis Miller)

Mike
 

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Discussion Starter #15
guitar maestro: Now, the highway part makes sense.......I hadn't thought of that.

Lonnie: I know how the converter works, but this wasn't a daily driver, so I wasn't really thinking of that, but I guess it wouldn't hurt anything to keep them.
 

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Here's a good question for you guys then....when I'm moving at 80+ in 4th, my car is sitting right around 3,000 RPM's....are the IMRC's open at that point, or aer they closed?
 

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That is what I have wondered for a LONG time. Is the "trigger" strictly rpm, or is it throttle position, engine load, transmission gear, etc... :2huh:

I know for a fact that my Gen II will not open the IMRC's while in park or neutral, not moving and the rpms over 3K. (I was trying to put some SeaFoam through it and I wanted the IMRC's to be open while I poured it in).

Lonnie can probably answer this question. :thumbsup:
 

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Well, another thing to remember is the first gen's are vacuum actuated, but I think there is also a vacuum pump or something that can open them as well. To many things to remember that are different between the 93-96's and the 97/98's.....I dunno how some of you guys keep it straight.
 

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The Gen I's are held closed with vacuum, but open when vacuum is removed (they have built in "leaf springs" that open them when vacuum is removed from the small IMRC actuators). The EEC removes power from the vacuum solenoid, which lets the vacuum bleed off and no longer hold them closed. Then the spring opens them.

The Gen II's are the exact opposite (and don't use vacuum at all). Their "Normal" state (i.e. when there is no signal to the controller) is closed. They are held closed with a coil spring located at the end of each IMRC manifold. When the EEC signals the controller to open them, a motor mechanism pulls on a pair of cables and opens the throttle blades. When you're below 3K, they just snap shut.

Quite the difference between Gen I and Gen II IMRC's. :beek:
 

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On the Marks, you have to also be at WOT before they will open not just at the 3000 rpm. One of the problems with the swap in a 94/95 Tbird using it's EEC since it doesn't have the drivers is they have to use a activation switch. The 96/97 do but most people don't want to mess with the wiring to make them work since the driver applies power at that that point and if you are using the Gen 1 setup then you have to build your own circuit to make it work, take power away to open. So most just go with the rpm activation switch so the IMRCs will open at the 3000 rpm point even if they are not at WOT.

I know this is going to really confuse some people now too.
 
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