Yesterday I replaced the seals and crush washers on the pressure valves on my 87 300TD. Everything went smoothly, except that one of the plungers came out of the pump when I removed the bottom section of the pressure valve with a stack of lanthanide magnets (I guess I should have used tweezers). Now the car runs poorly and smokes. Backing off the fuel line at the corresponding injector does not have any effect on the way the engine runs, and the diesel does not appear to be coming out at the same pressure as the other five lines when their nuts are loosened. I cleaned the injector according to the Mercedes procedure and it did not have any effect. I also took the pressure valve back off and checked that it was assembled correctly - no difference. I was reading in some posts from March (thread 1485169) about this problem, but have not come accross any information on how to remedy the problem other than to get the pump rebuilt. Is there any hope for a cheap fix here? Can I take the plunger back out and install in correctly? Any help would be appreciated.

Chris

I drove the car a couple of times this weekend, but no improvement. Still smoking and shaking. It definitely seems like one cylinder is not working properly. I'm really in a bind with this car and hoping that someone has some insights into how to install the plunger properly into the fuel pump. The part I am talking about is between 107 and 113 on the attached diagram.

Cheers, Chris

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There is a pin that sheares off when you put item 113 back in if it is not properly aligned. You can supposedly remove the side plate and should have enough pin left to drive it back into the slot. I am not sure of the exact procedure. Last time I had this incident happen to me I ended up removing the IP and taking it to a Bosch shop for repair.

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Jim

I might talk to a pump shop. Tell them what you did and get a repair estimate. If your car had been running really well prior to this event you might escape a rebuild charge. Try a second shop for price comparison as well. They may even consider repairing it on the car if deemed minor. Never know till you ask.