'82 240D will not stop running!

[LEHMAN88]

My '82 240D will not stop running when you turn the key off. I have looked and all the vacuum lines and they seem to be connected. This just happened one day out of the blue. I have to use the stop leaver to kill it. I'm guessing it’s a vacuum line some where but I don't know where to start. I purchased a MityVac hand pump today and need some direction on where to start. I don’t understand how the vacuum system works. I hope someone can give me step by step on what to do first, second, and so on so I can get this problem fixed. All the doors lock and unlock with the engine running. With engine off you can lock the doors once but they will not unlock until you restart the engine. This has been the case for years but it has never kept running when you turned the key off. It's driving me CRAZY!

[pawoSD]

The diaphragm in the shutoff valve on the Injection Pump could have failed too, or the ignition switch valve....

[tjohn]

Try this link for a vacuum diagram.

http://www.peterschmid.com/vacuum/1977_1985/616_617_91/616_617_91.jpg

[Stevo]

Pull the brown vacuum line off the shut down switch on the aft end if the injector pump. Test that switch by pulling a vacuum on it with the car running, if the car does not shut down, the switch is bad.

[LEHMAN88]

Originally Posted by Stevo

Pull the brown vacuum line off the shut down switch on the aft end if the injector pump. Test that switch by pulling a vacuum on it with the car running, if the car does not shut down, the switch is bad.

Stevo,

I pulled the brown vacuum line off and tested it. On the second pump pulling a vacuum the engine stopped! So where do I go next? Thank you for the detailed instructions this is just what I was looking for.

[toomany MBZ]

Had similar difficulties in my '82 300. (now my, someone else's, old 240 has this problem) Believe there is a vac leak somewhere. I disconnected the lines at the yellow check valve near firewall, engine shuts off, do not have "power" locks, a trade off I can live with.

[kerry]

Originally Posted by LEHMAN88

Stevo,

I pulled the brown vacuum line off and tested it. On the second pump pulling a vacuum the engine stopped! So where do I go next? Thank you for the detailed instructions this is just what I was looking for.

Disconnect the door lock system under the hood (yellow line) and plug the line. This will most likely solve your problem. You won't have vacuum door locks when you do this, but you can troubleshoot that system at your leisure. If disconnecting the locks does not make it shut down, the problem probably lies in the ignition switch.

[Stevo]

Originally Posted by kerry edwards

Disconnect the door lock system under the hood (yellow line) and plug the line. This will most likely solve your problem. You won't have vacuum door locks when you do this, but you can troubleshoot that system at your leisure. If disconnecting the locks does not make it shut down, the problem probably lies in the ignition switch.

His door locks work, so it might be the ignition switch or under the dash, in any case its time for detective work with the mity vac.

[LEHMAN88]

Thanks to everyone for your help! The engine now stop when you turn the key off! After unhooking the door lock system under the hood and pluging it with a golf tee, it fixed the problem and now it stops with the key!

I just learned even though the door locks worked, they can still be the problem with the engine not stopping. Now just got to fix the locking system!

Thanks again for all your help! This is an AWESOME forum!

Lehman

[kerry]

It sounded to me as if there could be a problem on the unlock side of the door system. Disconnecting and plugging the whole door system, quickly excludes a huge portion of the vacuum system that allows closer focus on the rest of the system.

[LEHMAN88]

Kerry,

Funny you say that, I checked both the lock and unlock side (yellow/Red Yellow/green) just in front of the drivers side seat to the left. When I pulled a vacuum to about 15 it held and the back doors locked. When I pulled a vacuum on the unlock side, the door slowly unlocked but never held a vacuum I must have pumped about 3 mins and still Zero. What does this tell you?

Thanks for the help,
Lehman

[kerry]

There's a leaking pod or a a leaking line somewhere in the unlock system. Did you try blocking off the doors altogether and seeing if the shut off worked?

[JimmyL]

Originally Posted by LEHMAN88

Kerry,

Funny you say that, I checked both the lock and unlock side (yellow/Red Yellow/green) just in front of the drivers side seat to the left. When I pulled a vacuum to about 15 it held and the back doors locked. When I pulled a vacuum on the unlock side, the door slowly unlocked but never held a vacuum I must have pumped about 3 mins and still Zero. What does this tell you?

Thanks for the help,
Lehman

There is a leak somewhere on down the line I imagine. Included in the door lock system is also the trunk lock and the fuel door lock. The other yellow line with gray stripe I believe goes to the vacuum reservoir. [that line starts at firewall]

[LEHMAN88]

Originally Posted by kerry edwards

There's a leaking pod or a a leaking line somewhere in the unlock system. Did you try blocking off the doors altogether and seeing if the shut off worked?

I'm not sure what you are asking me to do. How would I block off the doors to see if the key shut off works?

Thanks,
Lehman

[kerry]

Under the hood, near the vacuum booster, all the vacuum systems branch off the main line. I believe the shut off is brown and the door system is yellow. Pull the door system out of the rubber fitting and plug the rubber fitting so no vacuum is lost. Now the only vacuum related things hooked up should be the brake booster and the shut off valve/ignition system. (I don't think a 240d has any climate control vacuum controls).
Your door locks, fuel door and trunk will no longer work with vacuum while unplugged but it will be easier to troubleshoot the shut off system.