Got my new OVR today, new one has two fuse slots on top with 10 amp fuses, the one in my car has a single 15 amp. Any difference besides the obvious, pins look the same from what I remember, will look and check. But just wondering if there is a difference and will it work.

 

Only one way to find out

I know my 300TE has the two fuse and my 260E has the single fuse....They are of different sizes and have a different socket type.

 

yep, it works, same socket and after 20 mines of comparing schematics on them and that only 5 of the 9 pins have wires I plugged her in and it started. But It will still die after 3-5 seconds depending on the position its sitting. Think I just have a wiring connection issue somewhere. One of these days I'll get in there and check em out. Wished I had more tools with me here in Italy.

 

I double checked it for you, and it seems you have the correct one for the 1991 300CE...

What exactly is the problem you are experiencing? Obviously stalling, but under what conditions? Idle only? Cold? Warm? All the time? What other items have you replaced for this car so far?

 

Problems are-

Cold start, idle is an issue, once in awhile, morning mostly (cooler starts). It idles low, will start when pushing in clutch to slow/downshift. It used to have a hard time restarting after after shut downs more then around 2 hours, like something got heat soaked. But haven't had any problems with that lately.

It stalled after warmed up on the freeway once after warmed up, just cut off. Restart, dies after 3-5 seconds, just stops, after numerous tries of restarting, like it goes to timed cycle changeover (which shuts it down). I rattled the comp and OVR behind the battery, started up fine and drove home. Stop at a shop to ask a mech if they had any OVR's, while moving it to show him, it did the same thing, started and did after the same cycle. MOved the OVR around and it has ran fine since, till I changed it out today, moved it around a bit and all is good.

I've sprayed and soaked the throttle body and took the what I think is a pressure regulator, fuel cannister prior to injection pump off and blew it out. This I think cured the "heat soak" issue, or seemed to.

So, my problems are-

Cold idle issues

Inadvertant engine shut off (which I think is just a bad wire connection, broken wire somewhere)


I've played with LS motors, and the engine shutoff is like a VATS on the LS motors, starts for a few seconds and just stops. Prior owner (2 before me) had a pretty indepth alarm system installed, not used or hooked up, from what I can tell, but alot of stuff is still there. Might have to look at some of that crap too.

Not too concerned, as it seems reliable, but I got the wife and kid coming to visit and would rather have dependable transpo instead of dropping money for a rental.

 

I have heard of "bad" new OVP's...there was a post recently about a member (TinyPanzer over at mercedesshop.com) who kept experiencing stalling and idle issues and it ended up being the OVP even though he got a new one.

Any possibility of testing another one? Shutting off on the freeway just screams OVP. Of course though, check your negative battery cable as they can get brittle with time. Then check the voltage regulator on the alternator and see what condition the brushes are in.

I would also pull off the idle control valve and shoot some carb cleaner into it. It can get all bugged up and dirty inside and can cause rough idle. With the air assembly off, it's two bolts and its in your hand so it shouldn't take more than 2-3 mins.

 

took the idle control motor off this weekend and sprayed the crap out of the inside, seems to idle a lot better. Thanks for the advice. I think I could benefit from a cap and plug wire change to to help smooth it out. She's smooth but just not enough.

On the OVP, I really think its a wiring connection. Only time it does stall is when it falls out of its holder, which was broken when I bought it. Need to some double sided tape to stick it back up.