I just performed a valve adjustment on my '85 300 TD and somehow may have damaged a vac line, as the ignition won't turn off the engine. I had this issue awhile back and believe I plugged a line someplace and got it to work, but now I'm lost :\.

Hoping that someone can provide some insight as to best steps to troubleshoot the issue and determine where the prob lies. BTW- I can pull vac on one of the lines and it shuts off, so I believe the cut-off switch is working OK.

Thanks in advance for the help. This is a daily driver and it's embarrassing to have to pop the hood to shut 'er off. I appreciate the knowledge on this board!

Welcome aboard.

Best thing to do is get under the hood and start tracing out the vacuum lines. Start at the shut off valve located at the back of the injection pump. It should go into the firewall. Then you should see a brown line (IIRC) coming off of the main line going to the firewall to the ign switch.

Is this an 85 or 95 car? I'm not sure there was such a thing as a TD in 95.

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Jim

Nor any '95 MB Diesel passenger car that needs valve adjustments.

Assuming you simply knocked loose a line, look for brown lines from the brake booster vacuum supply line check valve to the firewall, then another brown line with red stripe from the firewall to the shutoff actuator behind the IP. That's all there is to the system under the hood.

Sixto
87 300D

Turn the black "Stop" screw on top of fuel filter to the right all the way to cut off fuel flow That is the emergency shutoff on these cars.

Don't drop that bolt ever. I dropped it, and the plastic stop part broke on me. So now its hard to turn. And its leaking fuel. But i hope that is irrelevant. Surely the plastic knob didn't hold fuel. Or the 3 ft fall to the concrete damaged it . Or i didn't screw the bolt tight enough when i changed the filter. Or maybe i left a washer out. Guess i better look at it. Point is that thing is over 100.00 just for that stupid bolt and shutoff valve. Crazy. That's what i hate about the 606 engine. EXPENSIVE parts all over the darn place.

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What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

I can't type...

appreciate the responses!

OK, from inspection, it appears that all lines are all connected (to something) under the hood. The rigid vac lines are very brittle. During my valve adjustment, I had inadvertently cracked one that comes off the check valve in the main vac line. I believe I fixed it ok by inserting a piece of hollow tubing. That check valve does not appear to be anything that would be easy to replace as it looks like it's crimped into the main line- no clamps.

It does appear that many lines travel through the firewall. Is their anything in the passenger compartment that I should have a look at? I seem to remember reading once that a bad door actuator could cause a lot of probs.

I remember back in the carburated days when you could spray WD-40 or carb cleaner on a vac connection and listen for the engine to race to find the culprit. No such luck in diesel world.

Do you have a Mityvac?

The engine shutoff system consists of source vacuum, a selection valve at the key switch and the vacuum actuator that does the job of pressing the STOP lever. A simple test is to apply vacuum directly to the actuator to see if the engine stops. If it does, go to the other end. Apply vacuum to the brown line at the brake booster vacuum supply line check valve and see if that stops the engine, Be careful handling the check valve. The nipples will be as brittle as the vacuum lines in the engine bay. AFAIK you have to buy an entire brake booster line; they don't sell just the check valve.

My 617 days are long ago. I don't remember if the STOP lever moves with the vacuum actuator as it does in the 603. If it does, no need to have the engine running. Just observe the STOP lever moving to confirm what you expect.

Whatever you spray in the vacuum system in these cars ends up in the engine crankcase. I wouldn't want WD-40 in there and certainly not carb cleaner!

Sixto
87 300D

I don't think the 617 stop lever moves like the one on the 603.

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Sixto- I do have a Mightyvac and will test as you suggested. Gracious thanks for your help!

So there are three lines going into the shut off valve. The "top" hose and brown line going to ign switch are intact, but there is a short 90-degree hose coming out of the side of the valve that is not connected to anything. I do not see a vacant hose anywhere that this should connect to. A bit perplexing to say the least. Anyone know where or what color line that bottom line should connect to? Thank you.

Start a new thread with the proper year in the subject line so more people familiar with the 617 system chime in.

Sixto
87 300D