Evening,

Here is what I have done recently that might effect my idle. I put a new o ring between the injector pump and engine, and put in a new throttle cable. When I took off the injector pump I set the engine at 15 degrees, and took off the side plug from the injector pump and right there perfectly lined up was the blade where I inserted the tool to keep the pump from turning while it was off. Before I put the o ring in I had some problems with the throttle cable where the plastic had come apart, and I had to do some rigging on that to keep the idle straight. After I put the pump back on I noticed that she had lots more power. I guess that was because of the o ring. After the pump was back on I put a new throttle cable on. The cable was so tight (not enough slack) it was hard to get it around the oil filter. From the cable you can increase/decrease the idle using an adjustment on top of the engine, and under the fuel pedal inside. I think I can get her to idle properly using those adjustments, but, when I increase the idle to where I need it to be in just a few seconds the engine will start to run away. and I have to shut her down. Right now I have to use my right foot to brake and keep enough fuel going to keep her running (until she gets warm then no idle problem) and brake. I thought about the glow plugs, but the the glow plug light come on. I thought about checking the vacuum from the vacuum on the side of the engine that controls the idle speed until she get warm, and check the vacuum on top of the IP that controls the idle. When I take the vacuum hose off that it has no effect on the idle. Anyway, hopefully someone might point me in the right direction. Thanks.

Hugh Sr

1984 190d (W201) 95,384

There are a few ideas to correct in your post. Let's start with some simple things and move on after they are set.

1)
-put the engine back to 15* AfterTDC
-check the pump timing using the same method you described

2)
-the throttle cable should be completely free of tension when there is no foot on the pedal. This is not how you set your idle.