Diesel Rover

First of all, I would like to thank all of you guys for the information contained in this forum. I've been searching and reading for the last day and trying to absorb as much information as I can. I think I have an understanding of what's going on with my truck, but I would like some other opinions just in case I overlooked something. Thanks in advance for the help and all your past replies as they have been a big help.

The truck is a 1993 W250 with an intercooled CTD. I bought this truck as a complete mess with a non-running engine and have been putting it back together slowly. I have no idea what servicing it has received but based on the condition of the truck, it was rode hard and put away wet for almost 400 000 K as a tow truck. Since I have had it, I have had the head rebuilt, I did the KDP, re-sealed everything, put the heater screen on a momentary switch, replaced the camshaft (one lobe gone) and lifters... I think that's it.

At this time, the engine runs very well at off idle, smooth, powerful, lots of oil pressure. The problem is at idle - it runs smooth, but then drops off suddenly to the point of stalling, then it barks to life with a puff of black smoke, and idles fine for a while, then does it again. It will do this for as long as it is idling, doesn't seem to go away when it warms up, the near-stalling episodes seem to get less frequent but they are still there. I am not driving this truck yet, so I haven't been able to really get it working hard or at op. temp, and it's only been running for a total of about 3 hours since I got it.

I have read all I could find with respect to VE injection pumps and their governor mechanism. I thought I might have had an internal problem with a broken spring on the governor arm (the "top hat spring"), so I pulled the top cover off and inspected the springs and they all appear normal. Of course, they might just be stretched or weak, but they don't appear abnormal in comparison with the photos I have seen for the 3200 RPM spring installation. At this point, here are my ideas for what might be wrong:

- Governor mechanism (flyweights and sliding "tube") sticking
- Top hat / "leaf" spring weak
- Air being sucked into supply line
- Lift pump not putting out adequate volume (this seems weird as it works great at speed)
- Bad injection pump

I am trying to figure out what to do next. Here is my logic, feel free to give me your opinions on what I should try in addition to this:

1 - Install clear line on supply to injection pump and look for bubbles being fed to the injection pump
2 - Check fuel press (2-3 PSI)
3 - Run some injector cleaner or other substance through pump and try and run it for a while to see if the governor "unsticks"
4 - Pull the pump and send it off to get rebuilt!!!

Obviously, I am trying to make darn sure that the issue lies with the pump itself. I have a good diesel shop nearby that can rebuild it but I dread reinstalling it only to have it geet all lopey on me again - It sounds like a methanol powered funny car!

Many thanks for all your help,

Cheers,

JL

wannadiesel

It really sounds like a worn governor to me, but it won't hurt to run through your list in order. If I was the guy paying for the pump rebuild I'd check everything else first, too. I'd definitely put a double dose of Howe's Meener Kleener in there and flog the snot out of the truck for a tank.

Diesel Rover

Thanks, that's what I figured but I just wanted to make sure. I guess I'm looking for a pump now!