delay before the RPM's drop

[JesterMX6]

figured i'd come in here because the e36 crowd is going around in circles.

is this something noticable on the e34's too?
http://forums.bimmerforums.com/forum/showthread.php?t=1215816

basically, you get up to speed in gear, press the clutch in, rpm's hang for a second or two, not like....because of the dual mass flywheel, but the computer actually holds the rpm's for a second, then they start to drop.

is this something found on the manual e34 as well? or just the e36. (speaking to the m50 guys here obviously)

personally, it feels like a computer controlled issue. wondering if maybe millerperformance has any input on this? somethign that can be controlled via the WAR chip maybe?

[Binjammin]

Sounds like a vacuum leak actually. When you close the throttle, you should have only a very small amount of air coming in through the IAC. The ecu sees that the throttle is closed so it puts it to idle. When you've got a vacuum leak coming in, it's unmetered air, so the ecu says "Idle" but the engine's still pulling extra air in. Eventually the IAC can compensate for it and it idles around normal.

I'd be looking for cracks in my intake boot past the MAF, or broken vacuum lines under the intake.

[JesterMX6]

not vaccuum leak. that was the first hting i checked on mine. and every e36 5spd owner who has chimed in on the thread has confirmed this.

its not an idle issue.

okay so u put ur car in 1st and take off.

go to 3400 rpms and shift
engine sits at 3400 rpms for about 1 second or so, then starts to drop
but by then i've already gone into 2nd and its now forced the rpms to be down at 2k or w/e for the next gear.

[Binjammin]

Well, it's a classic symptom of a vacuum leak, honestly I'd triple check that. Other than that maybe a hanging IAC? Check your throttle body to see if it's gunked up and binding?

The throttle cable plastic nuts can break and do funny things, how's that looking?

E36s didn't have EML did they?

[acet]

figured i'd come in here because the e36 crowd is going around in circles.

is this something noticable on the e34's too?
http://forums.bimmerforums.com/forum/showthread.php?t=1215816

basically, you get up to speed in gear, press the clutch in, rpm's hang for a second or two, not like....because of the dual mass flywheel, but the computer actually holds the rpm's for a second, then they start to drop.

is this something found on the manual e34 as well? or just the e36. (speaking to the m50 guys here obviously)

personally, it feels like a computer controlled issue. wondering if maybe millerperformance has any input on this? somethign that can be controlled via the WAR chip maybe?

My E34 540i does that!! But mine actually jumps up about 50-100 rpms before dropping. I have a dinan chip that is soon to be in the trash unless someone wants it for cheap.

[belizeanbullet]

Yea my 525i m50 does that. i actually posted numerous threads asking for help but no dice.

[JesterMX6]

i'm honestly wondering if it is a computer feature to help old people drive the car

[screwbiedoo15]

i'm honestly wondering if it is a computer feature to help old people drive the car

I highly doubt it. I used to have an e36 325i and the RPM's dropped smoothly once I pushed in the clutch.