OK youse guys HELP my 300 has been shuttin off with the key altho not very good takes a long time and really shakes. but this am i changed the oil and filters,oil & air now it wont shut off with the key but shuts off quick with the shutoff. also have all the gages and lights working but the tach. eny ideas? have a nice day and many thanks for all the help youve given me. i couldnt have it going without you guys Bobco se.ks.

somewhere. I would start looking under the hood in the vicinity of the firewall in front of the drivers side.
Jim
'85 300D
'95 E320
'97 CRV

My car had the same problem and I replaced the vacuum diaphragm that controls the injection pump. It is a little tricky to "hook" the new one on to the slide, so you want to pull on it a little to be sure it is engaged. This is a pretty common problem, and to check to be sure it is bad, take the vacuum line off the end of the injection pump and check for oil that has migrated past the diaphragm. I think the part was about 50 or so.

__________________
When I close my eyes, and inhale, I can smell No. 2.

Engatwork and Dieseldan thanks guys for the info this thing is bout to drive me out of my tree. i cant find a vac leak and theres only a little oil on the vac line that controls the pump. if im looking at the right thing. its white and has several lines to it. im wondering about a vac. gage i put one in the line from pump to brake booster where there two or thee line in front of master cyl. it shows 21 in vac and dont leak off. help bobco se ks

I had the same problem on my 76 300D. Turns out a vacuum line had come loose off my a/c temp control( in console). They must share a line or something.

Thanks steve o19 if my c.d. roms ever get here ill try that. im leary of doing eny thing else ive got the vac lin off the switch and cant get it back on. need to pull the dash cluster. Bob se.ks.

When my car would not shut off I replaced the control on injection pump. My suggestions would be the same as Dieseldan. To get at the ignition switch to reattach vacuum line, I pulled my off looking for oil, I removed the lower knee panel. My car would not shut off and oil leaked on carpet. Found out oil was coming from fuel injection pump being sucked thru shut off diaphram thru ignition switch and finally settling in brake vacuum booster. Ended up changing booster and diaphram.

Hey this is just an idea mind you. Do you have central locking? Try locking the doors and then turning the key off. (these systems DO share vacuum with the shutoff on my 300TD-T ) and I had a pair of bad controls in the doors!

Greetings Bobco,

First off, let's go down to our local parts store and buy a mighty vac tester. They run around $21.00 and will be quite helpful on many projects and repairs on a vacuum intensive car such as these. After this minor purchase, hook it up to the shut-off valve on the rear of your injection pump. With the engine running pull a vacuum on your mighty vac and the engine should shut down. If it does, watch the gauge and see if the vacuum slowly rises back up. If so it's your injection pump shut down vacuum valve that's gone bad. Almost all valves that go bad end up feeding your ignition switch with oil that can be seen or wiped with a rag and generally oil spotted where it comes out of the bottom vacuum breather hole under the ignition switch. If you don't find oil on your ignition shut off switch, chances are it's not the shut-off valve but perhaps the key diaphragm instead. Try the first test on the shut-off valve, let us know the results and we'll go from there. If you remove the kick panel and see oil on the bottom side of the key switch, it's the shut-off valve for sure.

Charles