Inside the IMRC Box!

[FastCougar]

Thanks to James (CustomCougars) for giving me his totaled Cougar's IMRC Box ... I always wondered how it worked.

This picture shows just why you don't want to hit someone that pulls out in front of you without warning ... besides a broken valve cover and god knows what else, this could happen. Not how the Actuator Motor is held in place by that orange rubber pad.
http://www.fastcougar.com/forums/attachments/IMRC_Box_Front_Cracked.jpg

The lid turned upside down after being removed shows the rubber pad that holds the solenoid in place. Other than this pad, the motor is free to move/come out of the box.
http://www.fastcougar.com/forums/attachments/IMRC_Box_Lid_Bottom.jpg

Here we see the gears from the actuator motor to the secondary throttle actuator linkage and the circuit board.
http://www.fastcougar.com/forums/attachments/IMRC_Box_01.jpg

With the circuit board lifted up, we can see how the throttle linkage works.
http://www.fastcougar.com/forums/attachments/IMRC_Box_Open_02.jpg

close-up of the circuit board ... pretty interesting stuff.
http://www.fastcougar.com/forums/attachments/IMRC_Box_Open_03.jpg

[CougarGT]

I almost took mine apart this week!
I was wondering the same thing
Thanks!
Good pics too

[Andy]

I know I'm going to sound like an idiot......BUT.......

What does a IMRC Box do?

[ZnCoug]

Andy - it opens/closes your secondaries.

[Draxas]

Hmm..I would assume that over time that solenoid could go bad, maybe that is why some of us 99's have the IMRC problem.

I recently met a Cougar owner in my town that also has a 99, his being an ATX. His IMRC works well for about the first 15-20 minutes of driving, but if he drives the car longer than that, his IMRC wont open anymore. He took his to our local Ford dealer when it was exhibiting the problem, and they told him it was the IMRC (DUHHHH!!!) and that they would replace the box for him. I took my car to the same dealer and reported the same problem (although I couldnt duplicate the problem at the time) and they wouldnt fix it for me. If he gets his replaced and it really does take care of his problem, then I will just buy a new IMRC from Gary Starr and install it myself.


Nikolas

[ChrisHightower]

I recently met a Cougar owner in my town that also has a 99, his being an ATX. His IMRC works well for about the first 15-20 minutes of driving, but if he drives the car longer than that, his IMRC wont open anymore...

Mine has the EXACT same problem. I really think something heats up and makes it not work anymore until it gets down past that temp again. I can even get it to stop working in the middle of a spirited WOT run. I can usually predict when it's going to stop working.

[Draxas]

Hmm....do you have that black cover taken off the top of yours yet? Mine happens ALOT during the Spring, Summer, or Fall...but rarely during the winter when it is so cold outside. I wonder if there is a way we can insulate it from the heat, without trapping heat in that box. I took the screws out of my box, but the cover looks like it was glued on...I guess they dont want us opening it or something....

Nikolas

[ChrisHightower]

No, my plastic cover is still on.

Maybe get the case JetHot coated :tongue:

I bet it's just a dodgy electrical component or solder joint. It does have some kind of glue that seals it. Just give it a good yank.

[Andy]

Thanks Zn:)

[Dopeshiet7]

I personally think the imrc is crap. Mine stopped working recently, so my secondaries stayed closed. I don't want to buy a new one. I just took my blow torch and made the gears hold the secondaries open. SOLUTION !!! Lost some torque but better than losing the whole upper power band. Because before the I opened them the car wouldn't accelerate past 5000 rpms.

[Draxas]

My solution to the problem (which really isnt a solution ;) ) will be to completely remove the butterfly valves when I get a larger MAF and the APEXi S-AFC...then I can tune the car to deal with not having the valves....... The AFC is key to tuning the car for larger TBs, MAFs, and elimination of the secondaries......



Nikolas

[OSUStallion]

What are the exact symptoms when your IMRC goes bad? Do you get a CEL?

[Draxas]

Personally i didnt get a CEL....and the guy near me doesnt get a CEL....i dont think that DopeShiet got a CEL as well..... my Ford dealership used this to their advantage so they could turn me down for service. "No CEL, No Service." straight from the lead managers mouth... needless to say, i was pissed..... :mad::mad::mad::mad::mad::mad::mad::mad::mad::mad: :mad::mad::mad::mad::mad::mad::mad:



Nikolas

[FastCougar]

The harness plug had 6 prongs sticking out that where hooked into the circuit board. This tells me that the ECU is probably monitoring the state of the unit, but it isn't a CEL causing problem. To test this, unplug the thing during the week and drive with it unpluged for a couple days ... driving in rushour below 5,000 RPMs isn't that bad anyway. NOTE: Don't do this unless you have a way to check the CEL and clear it (AutoTap, Alex Peper's ODB-II Scanner, etc.)

[FastCougar]

It would be too ironic if heat was causing the circuit board components to crap out ... guess why ... the maker of the circuit board is called "Sturdy Corporation" ... how funny is that!

[MaStaMooN]

If I knew where my Ford CD or Chilton guide was, I would look up in the OBDII codes for anything regarding the IMRC.. You should then see all of the circumstances that will trigger a CEL in regards to the IMRC.

I know I had a CEL and error code P1518 IMRC Stuck open.. So I know they will trigger a CEL. Im also pretty sure if you try and unplug it, you will throw a CEL also.

[ZERO]

alright so its a motor that opens the secondaries up? why can't we use for example the weapon R ECU to trick the comp into sending the signal to open the suckers up sooner? that would be pretty handy to get all your power as soon as you put the pedal down.... am i way off base or what?

[JScullin]

I think a few members have figured out how to either flip a switch or something that opens them when they want.

There's also another one on shutting down some fan that gives you an extra kick in the pants.

[ZERO]

wheres the how to for the secondaries switch thing and whats this about a fan?!

[RedThunder]

Intake Manifold Runner Control IMRC
I think i have same prob, i beleive it happens 90 percent of the time when its really warm, engines revs louder but no power is shown. I have noticed once i change my oil it doesnt happen really till about wheni have to change again. anyone have same prob?

[Dopeshiet7]

Not reving past 5000 rpms sucks on the freeway. But the real problem is power was lost after 3000 rpms that's horrible for driving on the streets. And it makes the car run rich. Because of the secondaries not opening i had a CEL for running rich in both banks and imrc stuck closed. :mad: But I didn't know this until I hooked up the OBD II scanner ( I always have a CEL from gutting the precats).

[PuckPuck]

As far as I know, there is no how to for making the IMRC open up at command. There is however a How To to hook up a little light inside the cabin of the car which will go on whenever the butterflies actually open. This switch will NOT go on if the IMRC is malfucntionning, which is a good way to find out if the IMRC is actually working (light not goign on when it should).

Also since I have this light in my car, I was able to do much investigation into when and why the IMRC will open. First off the IMRC is based on the throttle position AND the rpms. You need to be doing at least 3100 RPM (that's the rpm point) and have a TPS of xx volts which I have yet to determine the exact voltage.

Now If you ask me the only thing I would change in the ECU for the IMRC is the rpm opening point and put that lower to say about 2800 or 2900, that would help smooth out the little dip you get at that point on a dyno plot. I would not change the TPS voltage point however as that allows you to cruise around town or hit the gas and go.

The how to on the secondaires light can be found on MC-NECO.Com (http://www.mc-neco.com) Just go to the How To section and it should be posted there

[AirWolf]

Wouldn't opening up the secondaries earlier just move that dip in the dyno plot to the left? I'm not 100% positive, but I think that that dip is always going to be there as long as your secondaries are opening. If they were tied open, then the dip would disappear.

[MaStaMooN]

There has been dyno/track testing on opening points of the IMRC done on CEG. From what they have shown, opening the secondaries early is just not optimal.. Ford actually got this right in its research. Sure maybe bumping it down to 3000 rpm flat may help on a modified car, but from what those dyno numbers have shown, I wouldnt touch the opening point.. RPM wise anyway. Maybe make it more a TPS based change.. SO they would open without having to mash the pedal.. Better part throttle response when above 3000+ rpm?



Edit: I think the best thing to do is making sure they actually perform how Ford intended, not trying to change the way they are supposed to behave.

[FastCougar]

When I test drove the 2K2 Maxima (I know ... I'm hooked), the engine came on STRONG at 4K RPMs ... I mean STRONG! Turns out they have a dual intake setup similar to ours. They also have 1 litre more displacement and VCT, but I wonder how the VQ35 engine manages the secondaries? I posted about our similar setup sometime last night ... I will go view responses now and see what everyone has to say.

[badkitty01C2]

I posted a sh&%-load of info about IMRC's that I got from my Ford technical CD in a thread about OSUStallion's "very sick cougar" . There were 3-4 CELs listed. :)

Go here and scroll down. (http://WWW.fastcougar.com/forums/messageview.cfm?catid=10&threadid=27352)