New OVP Relay, shutdown questions - PeachParts Mercedes-Benz Forum

rsc52 · #1 03-27-2007, 09:06 PM

I have a 1985 300d and I just installed a "new" OVP Relay. This is the newer replacement unit. It does have (5) pins (plus the locator) instead of the (4) pins (plus the locator) that my original relay had...

It works! I now have a tach (which I've been trying to get working since I purchased the car almost two years ago!) and cruise control, which I had just given up on! The cruise is great by the way. The short drives I've made with it seem to maintain a rock solid speed.

The issue is that now when I shut the engine off it takes about 3-4 seconds to shut off. Before, it was almost instantaneous. Is it just coincidence or? It may also be the way it's supposed to be! As far as vacuum is concerned, the brakes work fine and of course the cruise works well. If I hold the brakes and shut the engine off, it takes an extra couple of seconds.

Is this normal? If not, what should I check?

Thanks in advance for your help!

d.delano · #2 03-28-2007, 02:29 AM

can I trouble you as to ask where that OVP is located? Thanks

Is the shutting off a gradual 'choking' or is it like you turn the key off and the car continues on a normal idle until it abruptly quits? If it's the choking then it's definitely vacuum related. If it quits abruptly then it still may be vacuum related, like a shutoff that sticks until it is overcome by vacuum which might take a few seconds. I had a vac leak inside the dash once, at a vac pod. Caused clunking when coming to a stop and gradual choking on shutoff. Make sure there are zero little vacuum leaks from cracked or disintegrating rubber connectors in the engine compartment first. Then check the vac shutoff on the back of the injection pump. You'll need a Mityvac tester for this. If the shutoff works on application of vacuum, it's not the problem.

rsc52 · #3 03-28-2007, 07:29 AM

Quote:

Originally Posted by d.delano

can I trouble you as to ask where that OVP is located? Thanks

Is the shutting off a gradual 'choking' or is it like you turn the key off and the car continues on a normal idle until it abruptly quits? If it's the choking then it's definitely vacuum related...

The OVP Relay is located to the right of the glovebox behind the dash. I remove the lower panel under the glovebox to access it.

It's choking down so I'm going to assume it's vacuum. It's strange that it started with the OVP? I suppose I could have nocked a hose loose under the dash.

I'll start checking things.

Thanks!