How do I increase idle rpm's?

[Autotechnica]

Here's the deal, my M3 clutch kit sometimes stalls my car when I drive it hard (clutch heats up) and the idle becomes very unstable. I've tried adjusting the idle by turning the screw on my throttle body. However, the idle will increase for about a minute, then all of a sudden it will drop back to normal idle RPM. Is the idle computer controlled and self-adjusting? I can't seem to raise it. Another method I was thinking of was finally getting around to installing my BMP adjustable fuel pressure regulator. I was thinking of increasing the fuel mixture a bit to bump the idle. Any ideas?

Thanks,

Bry

[dutchbmw]

The screw on the throttle body is for adjusting the CO %. You need to re-adjust that screw for the recommend exhaust fumes percentage. The idle cannot adjust because this is computer controlled, just what you said. I think the only possibility you have is to upgrade your cars DME software which costs a lot of dollars.

I have a (Dutch) technical book where all parts are explained from the Motronic computer who's fitted in all e36 BMWs. At this moment I've loaned it to a friend of my so I could tell you in detail about it.

As far as I know there's no way to increase the idle rpm. Good luck!

Pieter

[Kevin325i]

Yeah, it's just a simple screw on the butterfly lever that moves it one a little bit to raise the idle. Have the car running, and slowly adjust till you get to a desired rpm.

Here's a picture of what you're looking for.

Kevin

[Kevin325i]

a little closer...

[Autotechnica]

That's the screw/nut I played with. The idle went up, then it automatically came back down reguardless of what position the screw was in. As Dutch mentioned the idle is computer controlled and automatic. I'm all out of ideas.

Bry

[Kevin325i]

Interesting, WTF is that stupid screw for then? Oh well

Kevin

[Autotechnica]

As far as I knew it was for adjusting idle RPM's. However, Dutch says it's for adjusting CO %'s.

Bry

[thekid]

hehe... heres an idea. Because the gas pedal goes all the way to the floor... just push your floor mat forward a little bit so it puts the smallest amount of pressure on the gas pedal!!! for me... it happens to me all the time cuz short of tape or velcro theres no way to secure my matts.... so everyonce in i while I'll put the clutch in and the rpms will take off.... it's fun... but I checked just for you, and you can get it on there lightly enough for it to work. I know I know... but it may be your only option.

[Autotechnica]

Originally posted by thekid@Jun 20 2004, 11:34 PM
hehe... heres an idea. Because the gas pedal goes all the way to the floor... just push your floor mat forward a little bit so it puts the smallest amount of pressure on the gas pedal!!! for me... it happens to me all the time cuz short of tape or velcro theres no way to secure my matts.... so everyonce in i while I'll put the clutch in and the rpms will take off.... it's fun... but I checked just for you, and you can get it on there lightly enough for it to work. I know I know... but it may be your only option.

ghettoness..

I think I'd rather live with my problem.

[thekid]

yeah.... so would i...but then again... my cd changer is duct taped in place in my trunk until the mount gets here....

[Speedy-325is]

Idle problem...
Think it's a vacum leak??

The thread is on pg. 12.(sorry, i dont know how to link threads)
this one might help you.

i know the idle is comp. controlled but the cable that goes to the throttle body can get a bit to much slack in it. this slack CAN be adjusted manually.

let me know if u have questions.
Mark

[Autotechnica]

Originally posted by Speedy-325is@Jun 21 2004, 01:41 AM
Idle problem...
Think it's a vacum leak??

The thread is on pg. 12.(sorry, i dont know how to link threads)
this one might help you.

i know the idle is comp. controlled but the cable that goes to the throttle body can get a bit to much slack in it. this slack CAN be adjusted manually.

let me know if u have questions.
Mark

Rough idle isn't the problem. I have a bored out throttle body and that already made my idle slightly more unstable. However, I'm only experiencing this problem because of the lighter M3 flywheel. I've read about this and it seems to be normal whenever the clutch reaches a certain temp. When the clutch is hot (on the track for example), the car's idle would drop below the normal RPM, if I tried to rev it up to stop the car from stalling the idle would just dip then the car would stall. It can't be a vaccum leak. I inspect all my hoses weekly very carefuelly. I even put a protective SS braiding on the outside.

On the cable there is a black threaded knob, I've tried turning this and it doesn't seem to do anything. Is there something else I should be looking for? I've got an M42.

thanks,

Bry

[bitcore]

You could find a piece where the pedal in the cab's steel rod rests against another piece in the cab and put some tape around the rod so that it dosn't let the pedal come ALL THE WAY back, similar to the floormat method but you can't mess it up by moving your feet on the floormat

Otherwise, only other method I see is to adjust the DME computer, which is going to cost you.

[greennvmachine]

if he had a vaccum leak his idle speed would skyrocket

[Autotechnica]

I'm not going to do these mickey mouse jobs and make my pedal slightly depressed all the time. Is it just me or does anyone else see anything wrong with doing things like that? If I let off the throttle and want engine braking, the car will still be acclerating when I don't want it to be. It won't slow down as fast without braking.

It doesn't bother me that much that the car stalls after driving it hard. I can live with it, but if there was an easy fix such as adjusting a nut or screw, then why not? Anyways, for the time being it's bareable.

Anyone else have suggestions I would appreciate it. I have a Dinan chip, but I doubt that changes idle speed properties in any way.

Thanks,

Bry