High Idle OVP fuse - PeachParts Mercedes-Benz Forum

ragtopper · #1 01-18-2010, 01:50 PM

Still chasing high idle....
Just removed OVP fuse and idle dropped significantly. Re-insert fuse and idle surges again. Fuse appears okay. What next? Bad OVP?

Ragtopper
1982 380SL

alabbasi · #2 01-18-2010, 01:58 PM

Odd, the exact opposite thing should be happening.

ragtopper · #3 01-18-2010, 02:11 PM

Have cleaned ICV 3x. Voltage at ICV pin connectors reads .97 (low).
Have not checked Idle Control unit yet. Obvious next step?

Ragtopper
1982 380SL

ragtopper · #4 01-18-2010, 06:29 PM

Turns out its gotta be Control Unit, cuz I think I fixed it.

I decided to pull the unit. Since I had nothing to lose, I went the route of resoldering all of the leads (as recommended in many posts). When I reattached unit, idle immediately dropped to around 600. As I did the bendy/twisty, it would attempt to surge, so I re-soldered again. Lo & behold, it has stayed at 600 rpms at idle. Still has a very slight miss (but I think this is due to last mechanic trying to adjust the idle). Fingers are crossed that this indeed may be a permanent fix.

It should be noted that I am nothing more than a tinkerer - and probably had no business attempting this procedure. But hey, sometimes we get lucky.

Thanks to the many posts and valuable insight on this subject. Will keep all posted as to the longevity of this "fix".

Now, if I could only find that idle adjustment screw....

Ragtopper
1982 380SL

ragtopper · #5 03-01-2010, 05:19 PM

Well, after a couple months, somewhat of a high idle is back.....Around 1200-1500 rpms - but running bad/rough. Strong exhaust smell. Back to checking vacuum lines, etc.
Pulled pins again on Idle Control Valve and showing NO voltage - so I suspect Idle Control Module again.

This is getting old......

Ragtopper
1982 380SL

neds380sl · #6 03-01-2010, 09:42 PM

Rag- I got tired of messing with mine and bought a rebuilt unit, along with a new valve. Pricey, but works fine. It was way too frustrating messing with that thing. Ned

mike007 · #7 11-02-2010, 06:37 AM

I recently had a hi idle issue but after using carb cleaner on my IDV and resolder a couple of cold spots on my ICU it dropped approx 525rpm and holding. Now my issue is low idle any suggetions? Also I noticed my trunk will not open after the car has been off for at least several hours. I have to turn on the car to open the trunk. So whould that have any affect with my idle low issue? losing vacuum psi???? Also does any know where i can get a diagram of the vacuum system????

Thanks Mike

abiby · #8 11-02-2010, 06:49 PM

Quote:

Originally Posted by mike007

I recently had a hi idle issue but after using carb cleaner on my IDV and resolder a couple of cold spots on my ICU it dropped approx 525rpm and holding. Now my issue is low idle any suggetions? Also I noticed my trunk will not open after the car has been off for at least several hours. I have to turn on the car to open the trunk. So whould that have any affect with my idle low issue? losing vacuum psi???? Also does any know where i can get a diagram of the vacuum system????

Thanks Mike

I doubt that's a large enough leak to be causing your problems though my car takes several days to leak down.

You should find the appropriate vacuum diagram in this post:

http://www.benzworld.org/forums/r-c107-sl-slc-class/1453268-107-vacuum-diagrams.html#post4361171

If not, go through the rest of the thread.

Good luck!