I think I might have a problem with the IMRC. Sometimes my car feels WAY faster than others. I'll be driving around town and then I'll take off from a light and it feels so much faster. I notice the difference in the low end. Its almost like the plates are either sticking open at the low end or sticking half way open all the time. Then they close and act as they should for a little bit and its like I've got a supercharger or something. Dramatic difference. Could the dealer connect to the computer and see if there's a problem or are they going to say "drives fine" unless I bring in a dyno printout?

 

no!

 

Check and see if the cables are loose.

 

NO....


However, there is a test procedure for checking the unit out -- finding an intermittent would require someone that was motivated. A sticky plate and/or cable would not be that hard to find.

THERE IS NO OBD II code for it -- period!

There was some discussion some time back about building an IMRC actuation detector (a small micro-switch or hall-effect device with small magnet on the actuator arm) to trip a light inside the car when it goes off...

Didn't get built...

 

revining this one...

I am having intermittent IMRC issues.... somedays it works, other days, it doesnt seem to want to flip open...

There is a significant difference in the intake sound and speed with which the tachometer climbs to 7,000....
--> with IMRC functioning: at 3,800-4,100 there is an audible change in the intake track sound with accompanying acceleration increase in the tach... then at vtec, same again...
--> with IMRC not playing ball, the car seems to hit a wall prior to vtec engagement, and even with VTEC engagement, the car completely lacks its effortless redline character...

it is truly maddeding. I would almost prefer if it was actually broken and not working at all.

but this intermittent business is frustrating because I would be replacing a potentially non-faulty IMRC.

I have two hypothesis that I am hoping can be proven wrong or right:
1. My electrical system is not operating at full potential (weak alternator or battery). and the ECU recognizes this and is not allowing IMRC to open.... I noticed lately that my subwoofers when driven hard, are causing the dash lights to fade slightly when the bass hits

2. The 'main req'd' light is on.... this has been on for months with no issue with the IMRC. However, maybe the "situation" with the maintenance light has deteriorated and the ECU has decided to cut voltage to the IMRC.

Anyways, I will be pulling the 7.5 amp fuses in the passenger firewall and engine bay for 20min, and then restarting and checking if IMRC comes back to life....

I will update the group...

I am wondering if zip strapping the IMRC open permanently will feel better... I know it causes a loss of torque down low and that the IMRC opening creates a mild supercharger effect as air acclerates into the cylinders during wide open throttle runs up the rev range.... however, I suspect that with the testpipe/headers, that there is more power to be had a little earlier in the rev range... I think if the IMRC is kept open permanently, I will achieve more power a little sooner (like 3,300rpm) as opposed to 4,000

 

I think the main problem with the IMRC is that the teeth inside are made of plastic and they break over time and if your IMRC is having this problem sometimes the teeth will catch and other times they won't. The only real solution is to replace it.

 

Maintenance light is on a 7500mile timer. it blinks when u turn the car on then goes off normally. after 5000 it'll blink a few times after it should normally be off. then when u get to the end it stays ON.

u can reset this by putting key in the ignition, holding the 2 buttons to the right of the gauge bezel now while holding the buttons, turn the car to the ON II position. hold it for 10 or so seconds and should go away.

if I for some reason explained this wrong, the owners manual has it in it 63-65

yea probably just replace it man... which should work... and if not, then attending to the alternator would obv be you solution

 

Alternator wouldnt affect the IMRC.

rev the car in park to 4k and see if the IMRC flips. If not, replace.

 

ok i cant make it easier for you but anyway... i went trough this two weeks ago. Car felt sluggish like there was something wrong...

BAD IMRC
http://www.youtube.com/watch?v=T64kfrM74uo

after replacing it all the power is back so much fun to drive again
http://www.youtube.com/watch?v=cmvYTt9YLak

broken plastic teeth

 

BTW I'm on my second IMRC because I was experiencing the same thing your are now except after more time went by it stopped working completely.

 

I think I'll put off buying a new imrc and start buying the parts for the 3.7 intake mani ... Seems like a great mod... I really want to compare the sub 4,000rpm characteristics of each IM on torque...

Has anyone compared 3.7 IM with butterflies functioning versus left open? I wonder if the 3.7 IM with butterflies open feels torquier than 3.2 IM with working IMRC.... Below 4,000 rpm

 

you should connect the IMRC. You'll get more torque down low with the butterflies closed.

 

Bad IMRC. No way around it. Replace it. It's $90, & an easy DIY just do it.

 

IMRC ordered!

I think it is now stuck partially open... Dead zone between 4,000 to 5,000...