• Welcome to the Contour Enthusiasts Group, the best resource for the Ford Contour and Mercury Mystique.

    You can register to join the community.

Before you replace your IMRC or the IMRC transistor

X

xtascox

Hard-core CEG'er
Joined
Sep 13, 2007
Messages
1,132
Location
Philadelphia, PA
Since I bought my 98 Mystique over a year ago the IMRC would stop working after opening the secondaries 2 or 3 times. I never really looked into it until recently and now the IMRC has not stopped working since! It cost me $0 and only about 15 minutes, so before you go and replace the main transistor or even the whole box try this first. It's basically just cleaning.

Items needed:
Rubbing alcohol
Lint free cloth
Rag
Phillips and flat head screwdriver

1. Disconnect negative terminal on battery.

2. Remove the plastic cover on the front of the engine that covers the water pump belt and the IMRC housing and LEAVE IT OFF. If you take it off right after running your car, you will see why. It traps a ton of heat underneath and since I work with computers everyday, I know that heat and electronics do not mix.

3. Take out the 4 screws holding the metal plate on the front of the IMRC box.

4. Remove the metal plate. It may have a "glue" seal on it so just carefully use a flat head screw driver to pry it off. If your engine was running not long before you did this, you will really feel much heat builds up in the box.

5. Now check the back of the plate for excess glue that has run towards the middle and was not part of the seal. Clean it off, using a little rubbing alcohol and a rag, and make sure to get any excess off. Mine had a huge glob running from the outer edge to the middle of the plate. Probably caused some problems.

6. Take a lint free rag and some rubbing alcohol and gently clean any dirt off the back of the circuit board inside the housing. There was some brown residue(probably from the excess glue) across a few solders on mine, probably another problem. Make sure only to use a little bit of alcohol when cleaning it.

7. After making sure everything is dry, reattach the plate and return all 4 screws to their original holes.

8. Take it for a test drive and see if it fixed your problem!
 
ok I've definately had them not opening up before, it's wierd, the engin will rev just fine and go all the way out to redline but just feel like it has no power, usually when I just keep redlining it and shifting hard it will start to work again within a few pulls.
 
Loss of power over 3400 RPMS. When your car hits 3400 RPMS at Wide open throttle the secondaries open allowing much more air into the engine. My symptoms were that after running my car over 3400 rpms a few times, the secondaries would stop opening and I could definitely feel the loss of power. Listen to the engine too. It changes pitch when the secondaries open. If they aren't opening, it will be the same flat sound through the whole rpm range. If I shut the car off and started it back up, the problem would go away until the secondaries opened again.
Now if your secondaries aren't opening at all, even after just starting the car and driving it, you probably either have a broken cable leading to the intake manifold runner, or your IMRC is dead. Theres a fix for the second, search the forum for that. If its a broken cable, the whole IMRC needs to be replaced.
 
xtascox said:
. If its a broken cable, the whole IMRC needs to be replaced.
Click to expand...


You can replace the cable if you want to. My father and I did it with a piece of brake cable from a bike shop. And i even made it a little longer so the curves in it were not as sharp.
 
Also, there might be an excessive amount of carbon build up on the secondary butterflies. This could cause some sticking or not allowing the secondaries to fully close. I had so much crap in mine that I think it caused a premature failure of the IMRC. So I cleaned the manifolds off the car (how-to in the FAQ) and replaced the transistor at the same time. 5k miles later, no problems whatsoever (with respect to the secondaries anyway).
 
I think you got lucky on just a cleaning fixing an IMRC. Heat build up under the cover of an aged IMRC can cause it to malfunction. Did you remove the beauty cover and leave it off when you did this cleaning?
 
Yea, cover is off and staying off. After feeling the blast of heat when I took the plate off the IMRC, I knew that cover wasn't helping. And like I said, I haven't had the IMRC shut off since the clean a few days ago.
 
I I were to have to do it, I would already know how.


I would PROBABLY search it out on here to make sure that I have all my p's and q's in order.


I might start in the DURATEC forums, since I'd own a DURATEC.. then, since its involving HOW TO MAINTAIN(replace) a part, I'd probably go to DURATEC MAINTENANCE.. then, since I don't know where to look from there, I'd read the thread that says "read me first" and it might tell me that there are some how-tos located in there.


so.. to reiterate..


Go to Duratec Maintenance, and read the "read first" thread... find the How-to for IMRC replacement
 
Unless you want to get creative and design some sort of vent on the cover. I've seen it done before. Even then I'm not sure how effective that would be.
 
people on here also relocate the IMRC. like on the side of the battery box. the only thing limiting you when moving it is the length of the wire harness. the IMRC cable, like a bicycle brake line is longer.
 
Did anyone (beside the How-to poster) tried to replace the transistor in the IMRC box? I just goit a bunch of TIP121 and I tried to remove the board from the box yesterday, but for some reason, the black connector that plugs into the car harness is glued to the box... how PRACTICAL, thanks Ford!

It looks like some sort of hot glue... anyone have an idea how to melt/remove/get rid of that glue, so I can pull that board ou of that and see if that transisitor is the second venue of the Christ? I want my secondaries back!! :blackeye:
 
I scraped away at the glue on mine until it was almost completely cleared off, then it slides right out. I never tried to heat it up and risk damaging the connector, so I don't have any input there.
 
MrFord said:
Did anyone (beside the How-to poster) tried to replace the transistor in the IMRC box? I just goit a bunch of TIP121 and I tried to remove the board from the box yesterday, but for some reason, the black connector that plugs into the car harness is glued to the box... how PRACTICAL, thanks Ford!

It looks like some sort of hot glue... anyone have an idea how to melt/remove/get rid of that glue, so I can pull that board ou of that and see if that transisitor is the second venue of the Christ? I want my secondaries back!! :blackeye:
Click to expand...


That glue is a sealant to keep out weather.
 
CSVT1214 said:
I scraped away at the glue on mine until it was almost completely cleared off, then it slides right out. I never tried to heat it up and risk damaging the connector, so I don't have any input there.
Click to expand...

Thanks ! I'm gonna try that, I wasn't sure if the glue covered the whole connector surroundings or just the top.

Next step is to get that MAF to work!
 
You must log in or register to reply here.
Back
Top