IMRC Delete HELP PLEASE!!!
- Thread starter snake96
- Start date
Search. It's been posted about a dozen times on this forum.
Read this page carefully: http://www.classictiger.com/mustang/IAT-IMRC/IAT-IMRC.htm
It will explain the idea behind IMRCs and how to do a delete. It assumes you have a KB blower, but it will help some for NA people, too.
Here is the link to the specific documentation of how I did my metal plates using the TIG welding technique: http://www.classictiger.com/mustang/IAT-IMRC/IMRCDelete/default.htm
It will explain the idea behind IMRCs and how to do a delete. It assumes you have a KB blower, but it will help some for NA people, too.
Here is the link to the specific documentation of how I did my metal plates using the TIG welding technique: http://www.classictiger.com/mustang/IAT-IMRC/IMRCDelete/default.htm
Some people leave the motor in and hook a spring up to the ends of the cables to simulate the IMRCs so the PCM doesn't throw a code.
Some people build a little electrical circuit that plugs into the IMRC controller motor that simulates having the motor there so the PCM doesn't throw a code.
Some people claim that if you just leave the connectors unplugged it won't throw a code. I have not verified that.
Some people have their tuner turn it off in their tunes.
With my car, I turned off the IMRC code in the PCM using my SCT Pro-racer package. This also turns off the spark adder tables in the tune, so you have to add spark back in. Some people just add the IMRC spark tables back in to the base tables, but others, such as me, use the tables out of 03/04 Cobras as a new starting point.
Question 1) What sort of behavior will you see from the car without the spark added back in once the IMRC's have been turned off in the tune?
Question 2) What sort of behavior will you see from the car without the IMRC's deleted at all in the tune?
I have a specific reason for asking, but I'll wait for the response to explain.
Thanks
Question 2) What sort of behavior will you see from the car without the IMRC's deleted at all in the tune?
I have a specific reason for asking, but I'll wait for the response to explain.
Thanks
You will lose up to 8 degrees of spark advance above 3250RPM. Giving up spark advance gives up horsepower and torque above 3250RPM.
Assuming you do something to prevent throwing a code (such as the circuit described here: http://home.hawaii.rr.com/hfpc/imrc/), then the PCM will automatically add the spark back in when it thinks the IMRCs are open.
Okay. So here's what's up and hopefully someone can help at least point me in the right direction.
I installed MAC LT's, offroad H-pipe (which deletes the rear o2 sensors), and IMRC deletes, and smog pump delete. Car wouldn't idle afterward, but ran out on the road okay. I took it to have it tuned, which I expected would help with the idle, as well as give me a significant performance boost.
I got the expected performance boost (hit 301/296), but idle was still VERY rough, if it would idle at all. The tuner made some adjustments in the tune and the idle got a little bit better. However, just a few minutes after leaving the shop, the throttle started "sticking." That may not be the right description, but the engine wants to sit and run just above 3000 RPMs.
My tuner created about a dozen different tunes and I datalogged a bunch of stuff and we traded back and forth over email forever, but still nothing fixed the problem.
We've done a few things like... The EGR was still installed, but turned off in the tune. The EGR solinoid is normally open, which would open the EGR all the time if the PCM isn't telling it not to. So, I blocked off the EGR. The throttle return spring had come off, so we replaced it. I've datalogged the IAC and it seems to react as it should. My tuner seems to think the problem is my C&L MAF or BBK throttle body. I'm going to swap the stock MAF back in, just to test the theory, but I just don't think that's it (especially since it doesn't have this problem on the stock tune).
It never did this before the LT's or IMRC deletes, so it must be one of the two mods, or something I didn't get back together right, or something else gone wrong that's just a strange coincidence. Oh, it doesn't make any sense that it's a vacuum leak etc, because eventually it'll come down and idle around 800-1000 RPMs. I'd think a vacuum leak would be constant. It may "stick" at 3000+ for as long as 60 seconds, but usually after 15-30 seconds it just drops down and idles. After about 30 seconds of idle, it dies.
Oh, I don't have the problem in the stock tune UNLESS I RUN THE A/C. As soon as I shut the A/C off, it drops from 3000 to idle. I know when the pressure increases in the A/C the IAC is supposed to idle the car up to compensate for the load from the compressor, but I think it's more like something 1200-1500 RPMs. This makes me think the IAC could be bad, tuner says it's not the IAC.
I just need something to happen before this thing runs me out of money. Anyone have ideas?
I installed MAC LT's, offroad H-pipe (which deletes the rear o2 sensors), and IMRC deletes, and smog pump delete. Car wouldn't idle afterward, but ran out on the road okay. I took it to have it tuned, which I expected would help with the idle, as well as give me a significant performance boost.
I got the expected performance boost (hit 301/296), but idle was still VERY rough, if it would idle at all. The tuner made some adjustments in the tune and the idle got a little bit better. However, just a few minutes after leaving the shop, the throttle started "sticking." That may not be the right description, but the engine wants to sit and run just above 3000 RPMs.
My tuner created about a dozen different tunes and I datalogged a bunch of stuff and we traded back and forth over email forever, but still nothing fixed the problem.
We've done a few things like... The EGR was still installed, but turned off in the tune. The EGR solinoid is normally open, which would open the EGR all the time if the PCM isn't telling it not to. So, I blocked off the EGR. The throttle return spring had come off, so we replaced it. I've datalogged the IAC and it seems to react as it should. My tuner seems to think the problem is my C&L MAF or BBK throttle body. I'm going to swap the stock MAF back in, just to test the theory, but I just don't think that's it (especially since it doesn't have this problem on the stock tune).
It never did this before the LT's or IMRC deletes, so it must be one of the two mods, or something I didn't get back together right, or something else gone wrong that's just a strange coincidence. Oh, it doesn't make any sense that it's a vacuum leak etc, because eventually it'll come down and idle around 800-1000 RPMs. I'd think a vacuum leak would be constant. It may "stick" at 3000+ for as long as 60 seconds, but usually after 15-30 seconds it just drops down and idles. After about 30 seconds of idle, it dies.
Oh, I don't have the problem in the stock tune UNLESS I RUN THE A/C. As soon as I shut the A/C off, it drops from 3000 to idle. I know when the pressure increases in the A/C the IAC is supposed to idle the car up to compensate for the load from the compressor, but I think it's more like something 1200-1500 RPMs. This makes me think the IAC could be bad, tuner says it's not the IAC.
I just need something to happen before this thing runs me out of money. Anyone have ideas?
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Its not the meter or the tb. I used to run that same combo but switched to an accufab tb. my idle is fine with the c&l meter. Not to be a jerk but you did re-hook the vacuum lines and pcv lines? Cause that will give an irratic idle. What type of CAI do you have?
-Mark
-Mark
Right now I'm running the stock inlet tube and the K&N filter that came from C&L. I'm 95% sure I got everything that needed to be hooked up, hooked back up. I deleted the smog pump so much of that came off.
It's not your MAF if the motor runs okay with the stock tune.
Give me a call after 7pm and I'll try to work you thru some troubleshooting.
Okay, first I want to thank you for all the time you spent with me on the phone. I blocked off the the IAC and run the stock tune and multiple other tunes with no 3000+ idle problems. Removed the block, and it all came right back on any of the custom tunes.
So, I bought a new Motorcraft IAC today for $75 and installed it. Same problem. So now I'm right back to being clueless. Does this mean the tune has got the IAC fooked up?
So, I bought a new Motorcraft IAC today for $75 and installed it. Same problem. So now I'm right back to being clueless. Does this mean the tune has got the IAC fooked up?
Did you do the "carb cleaner"?
I used to have the same issue. I think my tb was sticking.
To fix my irratic idle:
I started the car and let it get up to temp.
Then i unplugged my IAC and the Car shut down.
I turned the tb adj screw less than a 1/4 turn and tried again. It BARELY idled. I'm talking 330450 RPMs.
So i gave the screw another very small turn and everything is perfect now.
I have 1 specific question. When the idle is at 3000 RPMs, is it during normal city driving, or is it when you get off a highway and come up to a traffic light?
Mine would only happen after having the throttle steadily at 65mph + for more than 5 minutes at a time.
To fix my irratic idle:
I started the car and let it get up to temp.
Then i unplugged my IAC and the Car shut down.
I turned the tb adj screw less than a 1/4 turn and tried again. It BARELY idled. I'm talking 330450 RPMs.
So i gave the screw another very small turn and everything is perfect now.
I have 1 specific question. When the idle is at 3000 RPMs, is it during normal city driving, or is it when you get off a highway and come up to a traffic light?
Mine would only happen after having the throttle steadily at 65mph + for more than 5 minutes at a time.
I did, and I got nothing. However, I did go down to see Mike at Mod Depot this morning. He didn't even try to tune it. He said it was acting just like a vaccum leak at the IMRC plates. So, I'm tearing it all back down tonight. He said I could bring him the plates and gaskets tomorrow and he'd check them out. I'll let you know what we find.
It would do it at the stoplight, stopsign, cruising down the highway, just about all the time.
Woohoo!!! Well, NA_SVT told me a story on the phone the other night about how he'd had someone build the motor for his old 96, and they'd forgotten the two intake bolts on the inside of the plennum. Well, I pulled the hat off my intake and whamo, the two bolts inside are missing. I specifically remember putting those bolts in, but they weren't there. I got to looking around, and they were laying down inside the intake. After applying lock-tite and torquing them back down, I decided to back all the other bolts out and do the same. There wasn't one bolt that I didn't take out with my fingers. Ugh... I feel like an asshole. Anyway, backed them all out, applied lock-tite to them all, torqued them back down.
Started it up, and it purs like a kitten. I'm sooooo psyched!
Started it up, and it purs like a kitten. I'm sooooo psyched!
Glad to hear you got it all figured out.
I have deleted the imrc's on my 98 cobra and it was telling me they were stuck closed before i did the delete. but my car seems to have a very ruff idel and some times it ldles at like 3000 rmp. I have done every thing posible to figure out my problem but am comming up short do you have any more ideas. there is someone that goes by hardcore, and he mentioned to bolts on the inside of the intake but his car is a 96 and mine is a 98 and it has no bolts inside of it and never did they never existed. if you have any ideas for me I would love to hear them, you can also reach me at [email protected]. i am realy at a loss.
what years had aluminum IMRC's and plastic IMRC's?
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