I tried to look this up on here, maybe I missed something because I am sure I am not the only one with this silly issue. Here it is:

I come to a stop, I turn the key to the off position, the car stays on. At first it was slowly die out now it at a point where it's always staying on and sometimes if I hit the pedal and let it sink fast it will shut off... Other times I have to pop the hood and choke it out.

I figured this might be a vacuum issue, does anyone know where to look, or what part is failing?

Thanks!

P.S. Coincidentally I ran into a fellow on the other side of the diesel pump with a W123 300D who has the same issue; only he gave up on it and just pops the hood every time he shuts the car off.

Thanks for looking and happy Labor Day Weekend!!

__________________
'87 300TD Estate (Panzer Wagon, Sold)
'95 E320 Estate (Sabertooth, Sold)
'94 E500 (Stark 1, For Sale)
'04 VW GTI (Rhino, Sold)
'12 VW GTI Autobahn (Shadow)

On the main vacuum line to the brake vacuum booster, near the rubber grommet at the first firewall, there is a small vacuum line the attaches to the built-in fitting on the main line. This is where the shut-off system gets it's vacuum to power itself. I would check here to see if it is broken off, and/or getting proper vacuum. Be careful, this fitting is 21 years old and is likely to be brittle and break off easily. Ask me how I know.

Quote:

Originally Posted by David Wilson On the main vacuum line to the brake vacuum booster, near the rubber grommet at the first firewall, there is a small vacuum line the attaches to the built-in fitting on the main line. This is where the shut-off system gets it's vacuum to power itself. I would check here to see if it is broken off, and/or getting proper vacuum. Be careful, this fitting is 21 years old and is likely to be brittle and break off easily. Ask me how I know.

Thanks David! Lucky mine was replaced with a Y-at that fitting, and through other discussions on this forum that Y should not exist or rather it should not go anywhere else, so I plugged the one end.

So I did some testing on this and here is where I am at. The line coming from the vacuum pump to the brake booster (large vacuum line) shows about 25' when the car is on (with Mitty Vac inline). After I turn the car off it drops to about 20' and the needle shakes violently within a small range.

The car does not turn itself off anymore; I was able to hit the pedal to raise the RPM's and let it drop which would result in the engine shutting off sometimes but lately I have to pop the hood and press the STOP lever down every time (or let it run like that until I get back from the ATM or Quick Check.

Upon further investigation today, when turning the car in the off position the STOP lever goes almost all the way down; at that point the STOP lever only needs to be pressed very lightly maybe less than a half of an inch before the engine turns off.

1. How does this car stay on if the electric diesel pump(s) are off? (I am use to gasoline engines with their fuel pumps cutting off fuel)
2. Is it bad to let the car ‘run’ when it is in the off position while I go inside the post office or other quick stops?
3. Does this help anyone further see how I can fix this issue?
   

__________________
'87 300TD Estate (Panzer Wagon, Sold)
'95 E320 Estate (Sabertooth, Sold)
'94 E500 (Stark 1, For Sale)
'04 VW GTI (Rhino, Sold)
'12 VW GTI Autobahn (Shadow)

1) Your car didn't come from the factory with electric fuel pumps. If it has them, it's part of a WVO conversion or someone got creative.

2) It doesn't hurt the engine to run without electricity. I don't know about the alternator. You should be more concerned with the safety and legal aspects of that practice. Removing the key locks the steering wheel but not the shifter!

3) Time for plan B. Seems you're not the type who'd have a MityVac. We can work around that...

Try this - locate the 5 way fitting atop the engine vacuum pump at the front of the engine. It should be inboard of the big fuel filter. Replace one line, any line, with a hose that will reach the injection pump and remove the hose that attaches to the shut-off actuator above the stop lever. Start the engine. Connect the hose from the vacuum pump to the shut-off actuator. If the engine stops, your problem is between the fitting along the brake booser vacuum line and the key switch. If the engine doesn't stop or is slow to stop, your problem is the shut-off actuator.

Sixto
87 300D

Sixto,

I have to admit this is my first Diesel car so I am not great with the terminology of everything nor do I know everything about the mechanics however I think you specifically, or others have helped with with problems I have had in the past (and I thank you for that of course) however I do have a MittyVac (couldn't tell exactly if you knew that by your comment on 3). I used to MittyVac to find out my VCV was bad among other things.

That being said I am still going to perform your test later on today after a birthday party I have to attend. (Maybe this morning if I have time )

That 5 way-splitter has been replaced with a 2-way Y that removes the two lines that go off to the left (if your facing the car from the front) for emissions (performed this a while ago while testing for the transmission issue and left it that way). My ALDA is removed too however the car shut off properly after both of those modifications.

Thanks for your help!

Frank

__________________
'87 300TD Estate (Panzer Wagon, Sold)
'95 E320 Estate (Sabertooth, Sold)
'94 E500 (Stark 1, For Sale)
'04 VW GTI (Rhino, Sold)
'12 VW GTI Autobahn (Shadow)

Okay so I ran your test and put a line straight from the vacuum pump to the shut-off actuator and the STOP lever went down as far as it had before and the car did not shut off (very close but not enough to make the engine really even sound as if it was trying to shut off).

By what I am reading if I am reading correctly you say that it is my shut-off actuator that needs replacing is that right?

Thanks again!

Frank

EDIT: I don't know if this will bring up the right page but I went to *************** and found there are a few replacements

Link: which one is it? =)
- Mine looks like the last one on the list, or at least the top part does.

Rereading my post, it sounds condescending. You even metioned having a MityVac in your earlier post. My apologies for being a jerk.

Yes, it does sound like the actuator is worn. It should snap down with only 15" of vacuum. You should be able to suck on a hose with your mouth to kill the engine. I wouldn't try it because there could be engine oil leaking into the actuator!

The link didn't work for me but I believe you mean the page with two aluminum things and a brass thing below. You want the brass thing. I don't see the plastic alternative with the nipple on top that was available previously. I've had a couple of 603s apart and I've never seen those aluminum things.

Do a search for DaveM/gsxr's instructions on removing the ALDA without removing the intake manifold. It makes a much quicker job of replacing the actuator. If you're due for glow plugs and injectors clips, might as well pull the intake manifold.

Good luck!

Sixto
87 300D

Sixto,

Thank you for getting back to me and looking at the (broken) link. Don't worry about the condescending comment because I won't! I fully admit that I am padawan when it comes to Diesel's and I appreciate your apprenticeship! I just wanted to be sure you knew I did have one in case you could modify your testing however I am pretty sure we are in agreeance with what the problem is.

I just clicked on the brass fitting and noticed that they also offer a plastic Bosch replacement piece which is a little cheaper, I think that was the one you are talking about. Should I get the plastic one or the brass one?

Brian and Jeff helped me with my ALDA removal and I have read Brian's thread on ALDA removal many times and I had trouble removing mine! Everyone here has always been a great help and I much appreciate that.

I had a plastic actuator for a year or so before I sold my SDL. No problems with it.

Sixto
87 300D

Thanks for sharing your experience. I'll order it up on Monday.

Is it a straight forward install or are there a lot of steps involved?

sixto: I just wanted to thank you for your help and patience (if I spelled that right, I don't think your a doctor). I replaced the shut off valve and that did the trick! I also bought and replaced the brake booster line as the split off went to a Y and was a poor fitting, the new one fits the line snug.

Thanks!

Frank