Please welcome the newest member of the faulty imrc club...

[Pyro81]

We just got some new neighbors, so i had to move my car as it was parked in their driveway. As i was moving it the Spend Money Light came on. So i grabbed the ole code reader and went to town. I got the code P1518 - IMRC malfunction (stuck open). Yippy skippy...
So i popped the hood to take a look and the imrc seemed closed to me. Turned the car on and walked out look again. Sure enough, it was open. So i went back and turned the car back off then back on again and hurried out to watch the imrc. It appears that a few seconds after the car starts it opens. So it's not a stuck cable. Somewhere it's getting the signal to open up. I think i might check the tps sensor later on. But i'm open to suggestions. I hope this doesn't mean that i have to replace the imrc...

EDIT: Okay, just had a thought. I doubt it's the tps sensor cause if it was reading wrong wouldn't it be telling the computer to dump more fuel in to compensate for the extra air? And iirc the rpms were reading normal at idle on the tack.

[B3NN3TT]

I hate those dumb things.

One of those "better ideas" from Ford...

Your cable might be fraying inside and hanging. I think the IMRC jerks the secondaries open at startup as kind of a test, to make sure they are working properly.

[Pyro81]

If the cable was frayed wouldn't it be stuck open regardless whether the engine is on or off? Cause it closes back up after i shut the engine back off. It's kinda acting like there is a short or wire grounding out somewhere.

[hotbug1776]

do you have a manual that give testing procedure (ohms reading or voltage readings) with a multimeter? Is this IMRC like my Idle air control valve? if it is, can you disconnect it and get a reading from the harness to determine if the computer is sending proper voltage/ resistance to the IMRC? sorry for all the ???, but you know I drive a GM product, so I hope these questions help you to brainstorm some idea's for a solution.

on a side note...got the new motor in, wanna go for a ride? :evil:

[Sled]

That is the EXACT issue I had. Mine would pop open just after starting and stay there. Remember reading all those posts of people who want to permanently pin their secondaries open cuz they thing it would give them more power? Well, now that yours will stay open go ahead and take a trip around town. None of them wanted to believe me that it makes the car suck donkey...well, anyway, just get a new IMRC; mine cost me $118.00 a few years back but I swear I saw them cheaper. Just buy and replace- sorry, no ghetto mod for this one. You should be able to fish it through without removing your UIM- just pay attention to how your cable is run right now and then feed the new one the same way. Might take 30 minutes or so. Have fun.

[hotbug1776]

WTF, IMRC?, UIM? IDK (LOL ROFL) TTYL BRB



sorry, just had to do it. what IS a IMRC and a UIM, Ford is so complicated, I just have an IAT, IAC, O2, and MAP. so sorry for the ignorance.

[B3NN3TT]

UIM = Upper Intake Manifold, or plenum. As opposed to LIM, or Lower Intake Manifold. The LIM is a separate piece that bridges the gap between the UIM and the heads.

IMRC = Intake Manifold Runner Control. A mechanical device that controls the number of runners that are open in the lower Intake Manifold at any given time (6 at low RPM's, 12 at high).

HTH!

[hotbug1776]

:biggrin: OK :tongue:

so in a nutshell, the IMRC, kinda controls how many valves are getting air? at idle the car is basically a SOHC 12 valve motor, but at throttle, the motor is a DOHC 24 valve motor (sound about right?). then why not leave the IMRC open all the time and have the ECM reprogrammed to adjust fuel regulation to the added air flow? (sorry about all the lame questions, but to an outsider this seems interesting). Ford, if this is how the setup works, was trying to make a kind of D.O.D. motor setup, like the new Hemi's. which could have been better controlled by Eliminaton of the IMRC and better control of the fuel delivery and ignition timing control. Why not let the motor run on 4 cylinders at Idle (just shut off two) and kick them on at 10-25% throttle. I'm rambling now, but I see no need for all this "extravagant" extra that car makers feel the need to burden us consumers with. All that the extra confort got me was a new motor when it failed (it's a good thing sometimes as well ;) )

[Pyro81]

There are procedures to test ohms and whatnot on my ford cd. I'll do that when i get time. But i probably will just end up replacing it.
Andy, if you leave them open the car will run like [censored]. I think it will still run like [censored] even if you compensated by adding more fuel. Iirc when they are closed it results in better bottom end power.

so in a nutshell, the IMRC, kinda controls how many valves are getting air? at idle the car is basically a SOHC 12 valve motor, but at throttle, the motor is a DOHC 24 valve motor (sound about right?)
That is correct. From 0-3500 rpms the imrc stays shut only allowing one of the two intake valves per cylinder to draw air. And at 3500 rpms the imrc opens to allow the other intake valve to draw air. Both exhaust valves are used at all times. So actually (at an effort to confuse you) sub 3500 rpms only uses 16 valves, and 3500 rpms and up uses 24 valves.

Edit: Andy, how is the motor running? I really wish i could of made it out. But homework was a [censored] and took me several hours. Anyways, i got nothing planned this weekend, how about you?

[hotbug1776]

I could come out right now If you like. nothing really planned for today, jusy lazin around. need to get the motor to 300 miles for the breakin, I got about 30 of so miles to go.

[Tygerr]

that sucks mang... hopefully you can figure it out w/ your multimeter, i would absolutely hate spending money on repairs

the 2.3 motor came in the z24 in 97 correct? i believe that's right, i bet that's one quick sunfire, any track times?

[hotbug1776]

Originally posted by: Tygerr
that sucks mang... hopefully you can figure it out w/ your multimeter, i would absolutely hate spending money on repairs

the 2.3 motor came in the z24 in 97 correct? i believe that's right, i bet that's one quick sunfire, any track times?

close, but it came out in 89 for Olds as a "v-8" killer, in 91-93 it was the most powerful version of it's life, the W41 with 190whp equipped with stock intake and exhaust. the motor I got is a 93 HO (180 stock HP to the wheels) with modded cams, a sports intake, sports exhaust manifold (working on a header), and racing computer chip. with my CAI (a real CAI drawing air from under the car) and the listed mods, I'm at a little over 200whp. I need to get motor mounts, and suspension pieces to put more power to the ground, but, I'm on a tight budget right now (as we all are, huh?).

I'll get over to Brians house sometime this weekend and have him snap some shots of the new motor, after it's first oil change (going in it's memories scrapbook :crazy: ).

it's kinda scarry driving a Sunfire as fast as mine will now go, (no speed limiter, and an extra grand on the rev limiter) in the blink of an eye if I downshift into 3rd at 50mph, I'm doing almost 100mph, the old speed limiter was at 108, and the speedo only goes to 110mph. you can bet when Norwalk is open for buisness and the weather is nice, I'm going to make a few passes.

BTW Brian, may need you to work your magic on a piece of aluminum for me to mount some gauges in the Sunfire dash pod (HEHE)