Idle irregular when in gear and not moving.
04-07-2019, 08:42 AM
#1
Junior Member
Thread Starter
Join Date: Apr 2007
Location: Staten Island, NY
Posts: 35
Received 0 Likes
on
0 Posts
1996 E320
Idle irregular when in gear and not moving.
96 E320 . W210
recently replaced the throttle body after having a recurring problem with engine tripping ASR warning and sending tranny into "Limp mode".
TB replacement resolved ASR/Limp mode issue (suspected bad wiring loom with biodegradable wiring insulation)
but now I have an issue with the idle being irregular.
Idle is fine when in park, idles around 650 rpm, steady.
the problem I am encountering is when car is at a stand-still and in drive. the idle fluctuates in a broad range (1,000-500 just before stall) but then it fluctuates into a
smaller and smaller range, until it settles down to a normal idle speed somewhere between what looks like 600-700 rpm.
I'm sorry I don't have any sophisticated diagnostic equipment to give a more detailed description.
Is there an easy procedure to reset the on board computer, "relearn" the new idle (throttle position) ?
I played with the adjustment screw on the throttle cable tensioner a little, should I leave a bit of slack or make it tighter? or am I on the wrong trail?
I was told that the TB install would be like a "plug and play" type situation, not requiring a computer to reset codes or programming... was I misinformed?
Hoping one of the resident "big Brains" can help me resolve this issue with a fix!!!
My sincere thanks, as always, to the great advice and insightful explanation s this forum has given me over the years.
Wayne
recently replaced the throttle body after having a recurring problem with engine tripping ASR warning and sending tranny into "Limp mode".
TB replacement resolved ASR/Limp mode issue (suspected bad wiring loom with biodegradable wiring insulation)
but now I have an issue with the idle being irregular.
Idle is fine when in park, idles around 650 rpm, steady.
the problem I am encountering is when car is at a stand-still and in drive. the idle fluctuates in a broad range (1,000-500 just before stall) but then it fluctuates into a
smaller and smaller range, until it settles down to a normal idle speed somewhere between what looks like 600-700 rpm.
I'm sorry I don't have any sophisticated diagnostic equipment to give a more detailed description.
Is there an easy procedure to reset the on board computer, "relearn" the new idle (throttle position) ?
I played with the adjustment screw on the throttle cable tensioner a little, should I leave a bit of slack or make it tighter? or am I on the wrong trail?
I was told that the TB install would be like a "plug and play" type situation, not requiring a computer to reset codes or programming... was I misinformed?
Hoping one of the resident "big Brains" can help me resolve this issue with a fix!!!
My sincere thanks, as always, to the great advice and insightful explanation s this forum has given me over the years.
Wayne
04-08-2019, 04:39 PM
#2
MBWorld Fanatic!
Frankly - when you are coming to a braked stop (or parked with transmission in neutral) and your E-Class drops below normal idle - almost feels like it's going to stall - catches itself and jumps back up - then srops again - normally that is a sign of a failing MAF.
For your car there are two different MAF's - one with "round connector" and one with "oval connector" - you need to look to see which you have.
Recommend replacement with Genuine Bosch Only and ONLY from a reputable on-line source (oft mentioned autohausaz.com) since the MAF is one of the most counterfeited MB parts in the world - and the only thing worse than a failing MAF is a cheap-sh*t China knockoff.
For your car there are two different MAF's - one with "round connector" and one with "oval connector" - you need to look to see which you have.
Recommend replacement with Genuine Bosch Only and ONLY from a reputable on-line source (oft mentioned autohausaz.com) since the MAF is one of the most counterfeited MB parts in the world - and the only thing worse than a failing MAF is a cheap-sh*t China knockoff.
