steam cleaned engine, now it won't turn off

[roy harvey]

Hi folks,
My second try at this post. Can't find if the first one went.
I steam cleaned my 300 SDT and immediately afterwards it would not shut off! I can't see any obvious vaccum lines distrubed, no fuses out. Any ideas? Can someone tell me the exact vac hose I can look at?
Any help appreciated,
Thanks,
Roy

[Palangi]

It's not possble to tell you exactly which hose. Generally, you need to look in the area around the oil filter, injection pump and brake booster line area. It could be a hose pulled loose or it could be a damaged vacuum junction. By vacuum junction I mean the black rubber X or Y parts where the vacuum lines meet. Look closer, you will find it.

[KCampbell]

If you look at the rear of the injection pump I think you'll find a white plastic valve body, with a couple of vacuum lines (plastic pipes) connected to it. I think this is the fuel shut off. All the vacuum lines are fed from what amounts to a vacuum manifold by the brake booster, there's a thick black pipe that comes through the first firewall to this area from the vacuum pump on the front of the engine.

Because the vacuum lines all arrive at this manifold, any one of them leaking, almost anywhere under the hood, could cause the shut off not to work. I think what you'll have to do is start examining the rubber Y and T pieces that join the pipes together until you can find the culprit. I don't think there's a much more scientific approach than this.

I'm assuming that you have a 300SD, later than '81?

Kevin

[P.E.Haiges]

Roy,

KCampbell is incorrect. The white plastic device on the back end of the IP is not the shut off, its a vacuum valve that controls the vacuum to the transmission. Don't mess with it.

The fuel shutoff device is underneath the vacuum valve has 1 brown vacuum line going to it. Trace the brown line back to see if it is disconnected somewhere.

P E H

[Carrameow]

KCampbell is incorrect

Boy I get criticized for speaking my mind at work and at home....I'm glad Mr. Haiges doesnt pull punches

[KCampbell]

Hey, I said I think twice. That's my out for being wrong.

Kevin

[phantoms]

If that line is not disconnected, pull it loose and have a friend shut the car off while you check to see if it gets a vacuum. If not, start tracing that line through the firewall to the back of the key switch. If you don't find any loose fittings or disconnects, then check the second hose going to the key switch is hooked to it. If it is, remove it and see if it has a vacuum while the engine is running. If not, reconnect and start tracing it back through the firewall to it's supply. However, if it does have a vacuum, there's a chance the shutoff switch could have went bad.

Here is a diagram of the shutoff system.


And this posts conatins the rest of the vacuum diagrams.