'88 107...high idle in neutral/way rough in gear

[Rickysa]

I know high-idle has been covered extinsively, but....

I've done a search but couldn't find an answer...the idle control valve is good, idle control switch is good back to the CIS-E.

The only resourse I have is alldatadiy...trying to find troubleshoot info is way frustrating...the only thing mentioned is lamda which requires a special tool?

Any help very much appreciated

Rick

PS. Title should read '86...sorry for the confusion

[rocky raccoon]

Rick:
Laboriously chasing down vacuum leaks fixed all of the idle and running issues on my 88 560SL. Where is your "economy" gauge at idle? If it is not pegged to the left you have a large vacuum leak. A smaller leak may not show so dramatically.
Look closely at the vacuum fitting that comes out of the intake manifold at the rear (firewall side) of the engine on the passenger side. That fitting has a soft rubber attachment to the hard vacuum line. It is vulnerable to heat and oil and deteriorates before any other.
Let the forum know what you find. It can be helpful to others. Happy Hunting.

[Rickysa]

Thanks so much for the reply (and I apologize for not posting here first..new to this forum)

I was hoping/dreading it would be vacuum related, while although tedious, usually a simple fix....having just done so on the climate control on a 126.

It will be a good exercise to go over them all, as I'm sure several are brittle from just a cursory examination. Fortunately, I do have a good vacuum diagram!....and it's nice to know another '88 560 owner is here for help

Rick

[Arthur Dalton]

ABS lamp ON ????????

[Rickysa]

Originally Posted by Arthur Dalton

ABS lamp ON ????????

Yessir....as is the SRS...can I kill more than one bird with one fix?????

[560SLroadster]

I had the same problem, fast idle and ABS light on. Problem fixed when corroded
contacts on idle valve cleaned and ABS fuse changed.

[Rickysa]

Originally Posted by 560SLroadster

I had the same problem, fast idle and ABS light on. Problem fixed when corroded
contacts on idle valve cleaned and ABS fuse changed.

Thanks for the help!

The idle valve checked out ok per the ohm test (plus cleaning and a shot of Corrosion X), and the ABS fuse looks good, but I"ll but a meter on it to double check. I did check the Economy indicator, and it wasn't nearly pegged, so I guess a vacuum issue as well.

Again, thanks for your help....no local dealer (not that I would use one ) or indie either...so my resources are the limited service info and you good folks.

Rick

[Arthur Dalton]

While it is running, tap on the OVP w/screwdriver handle..look for changes..
If yes, pull OVP and clean the pins/sockets and retry...if still yes, replace the OVP.

[Rickysa]

Originally Posted by Arthur Dalton

While it is running, tap on the OVP w/screwdriver handle..look for changes..
If yes, pull OVP and clean the pins/sockets and retry...if still yes, replace the OVP.

Arthur, no changes...idle at 1500 (sometimes 1100), ABS still lit....10A fuse on OPV not blown.

Other ideas? (and thanks!)

Rick

[Arthur Dalton]

I you find no vac leaks, my thoughts are still OVP b/c of ABS coupled w/high idle...

[Rickysa]

Originally Posted by Arthur Dalton

I you find no vac leaks, my thoughts are still OVP b/c of ABS coupled w/high idle...

No vac leaks that I could find, so I'm replacing the OVP...I'll let you know how it goes...thanks!