Gooday - imrc

bobsleigh

Active user
Mar 7, 2014
90
13
Not ts
So went to the scrappy today to get a leccy window relay. My old one was shot. After sorting that out I went onto the bigger issue.

My IRMC wasnt working. I took it appart and sprayed contact cleaner all over it. After it dried, I tested it and it worked. So to address the heat problem I unbolted the unit and found a fella who put his next to his airbox. Now I have only cable tied it atm but when I getva bit more time ill try tidying it up a little more but after half hour of driving its still working fine. Im thinking of trying to mount it under the airbox if there is enough space. This area seems well away from heat
 
Good fix!

Mine is dangling under the battery tray so it gets plenty of air, the loom just reaches.....I really shoould extend it especially as I have the cable ready to go on!
 
Yep, good fix - and probably what should've been done with them in the first place. I can't imagine what they were thinking putting them in a place that gets so heavily heat-soaked.

Really must get around to moving mine, (even though it's a repaired one with the uprated transistor) but my loom is very brittle so will need to do some work there at the same time.
 
Seems very common problem but what a difderence it makes. Extending the loom is a good idea but im not confident enough to take that on. Also the exhaust sounds way better now. Just fuel is burning fast now as I cant keep my foot off the loud pedal :)
 
I appear to have lost my kick at 4k. It was fine when I put it of the road a couple of months ago.
So my question is what fails in the IMRC and is there a how to?
 
I appear to have lost my kick at 4k. It was fine when I put it of the road a couple of months ago.
So my question is what fails in the IMRC and is there a how to?

Have you lost it totally, or just when the car is hot? If you've lost it totally I would check the connections and get a code reader on the car. Worst case, replace the unit totally. I have a couple spares if you're in need.

If it's after the car is hot, it's a transistor on the PCB inside the IMRC housing that's gone. Over time, the encapsulation material breaks down due to the heat, and the transistor stops switching when it gets hot.

There's a couple of ways of fixing this;

1) Replace the transistor (requires soldering obviously).
2) Relocate the IMRC to behind the battery tray.
3) Both of the above.

Note that a "failed" transistor will still work as long as it doesn't get hot, so you could do 2) above and it will carry on working pretty much indefinitely, though that's not ideal.
 
I will relocate it in the morning but it does appear to have gone totally.(n) What part is the transistor?
 
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Cheers guys :beer:

The strange thing is the car has loads of power right through. Just not that boost at 4k.
 
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has your fuel consumption drastically changed on short runs the kick comes from the secondaries opening and the car running on 6 cylinders rather than 3, sounds like yours is stuck open which would mean that travelling at low speed you will be burning more fuel than you need to so fuel economy should drop
 
has your fuel consumption drastically changed on short runs the kick comes from the secondaries opening and the car running on 6 cylinders rather than 3, sounds like yours is stuck open which would mean that travelling at low speed you will be burning more fuel than you need to so fuel economy should drop
This is what I was thinking. I'll need to keep an eye on the fuel then.