Hey all,

Here's my long story this time! 1992 300D 2.5 Turbo, 217k.

So we were going to take it on a long weekend road trip from Mpls to Chicago and back. A small fuel leak from the injection pump appeared about a week before, but the car was running fine otherwise. So we decided to get the O-rings changed the day before we left. I was running out of time so I took it to a local MB dealer which I don't really like, but they are really close to my house. I talked with the service manager and a tech who is an old-time dieselhead and he said he'd bring in the spline socket to change it out tomorrow.

So I left the car with them, and picked it up the next day, work completed. The IP was dry as a bone (and still is to this day) but the idle was a bit funny, almost like it was missing on one cylinder. I thought there might be some dirt stuck in the lines, so I gave it an italian tune up on the way to a quick appointment. Power and acceleration was good. Still idling funny.

So I took it back and talked with the tech. He said that either the IP pump timing (and thus the engine timing, he said the IP was driven by the main timing chain so if the engine timing was off the IP timing would be off) or else my injector(s) were dirty/clogged.

I said ok, and we went to Chicago and came back without incident (and without a new car, which was part of the trip, doh!). 36mpg, best economy ever in that car.

So now I've driven it for a couple of weeks and it's been exactally the same, funny idle, good power, 28-30mpg aroud town.

I decided to purge it, as that should really clean out any gunk in the system, so I did that this afternoon. The engine is quieter (as usual when purging) but still idle's weird.

The IP is dry, no leaks. The metal fuel hoses coming off the top of it and to the injectors are straight, not twisted or anything. No fuel leakage at the injectors. Idle is good at aobut 750rpm. Car never dies or hesitates. Idle was smooth (relatively for a diesel) with a good rythmn before the service was done.

Fuel filters are pretty new, but I want to change at least the inline since I purged. Will do that this week sometime.

How do you recommend I proceed from here? Any testing I can do on my own that can help narrow down the problem? I don't want to bring it back to this same dealer for "general diagnosis" as I don't really want to bring the car to them at all. It's my fault for bringing it there in the hurry in the first place, I admit that.

Thanks for any help...........

-m

__________________
Now:
2018 Tesla Model X
1999 S500 Grand Edition 164k
1992 300D 2.5 Turbo 287k
2005 E320 4MATIC wagon
1991 Alfa Romeo 164L 99k (sleeping for a while)

Then: 96 Lincoln TC, 93 Lincoln TC, 87 560 SEL, 87 300 SDL, 80 300D, 89 560 SEC