Injection Pump Problems

[KaiserM109]

I would like to find a TM that shows the INSIDE of an injection pump on a 1966 M109A3. The engine is an LD-465-1 without a turbo (See photo of data plate).

As I remember it, working inside the IP is a depot level job and apparently is not included in any TMs that I can find, including the ones that SCSG-G4 sent me on the thumb drive.

My problem is definitely RPM related and not fuel flow related. When it is cold it runs fine, but as soon as it warms up it begins “sticking” at 2100 RPMs. The symptoms are identical whether it is under load on a hill or sitting in its parking space in neutral. As it gets warmer it starts “sticking” at 1700 and 1800 RPMs. After a while it will not go past 2200, even with the pedal floored.

I have bypassed the FDC properly and that made no difference. I have taken the FDC and the part directly under it off and inspected and cleaned it; no change.

It ‘feels’ like something gets sticky when it warms up and it seems to me that disassembling it and cleaning it ought to work, but I would like to read a TM on the subject before I dive in.

If anyone has had this problem too, please let me know what you did about it.

Arlyn

 

[Floridianson]

The TM Troubleshootinng the 465 and 9-2910-226-34 Is all I have downloaded.

 

[KaiserM109]

I went back through all the TMs I could find that did anything more than mention the Injection Pump, including TM 9-2910-226-34 mentioned by Floridianson, and did not find what I was hoping to find. TM 9-2910-226-34 has as good a description and drawings of the IP as any, but there are no specific troubleshooting guides that address my problem or instructions on the proper way to disassemble it.

I can’t believe that I’m the only one that has had this problem!!

Since I have bypassed the FDB, the Movable Plate no longer moves. That means that the 3 adjustments related to it, the Guide Adjusting Screw, The Smoke Stop Cam and the Droop Screw all boil down to any one of the above. I opted to disable the Smoke Stop Cam, leave the Guide Adjusting Screw alone and make all the adjustments with the Droop Screw. I got it to a point where it runs well until the engine comes up to temperature. Then it craps out and I have to wait 20 minutes for it to cool.

We were 5 miles from the storage yard when it got really bad. We made it back in 1/2 mile increments. ‘Long afternoon!!

Does anyone have a complete IP for sale? How about a whole engine; I'd like to have a turbo.

 

[gringeltaube]

I would check the LDS465-1 Troubleshooting Manual ...... (again)

G.

 

[Recovry4x4]

Have you adjusted the throttle stop yet? Checked for binding linkage? We had a truck that flattened out at 47 MPH. No adjustments made a difference. 240 miles into the trip a light in my head went off and I adjusted the throttle stop. 58MPH the rest of the way home!

 

[m-35tom]

you want TM-9-2910-226-34

 

[KaiserM109]

Have you adjusted the throttle stop yet? Checked for binding linkage? We had a truck that flattened out at 47 MPH. No adjustments made a difference. 240 miles into the trip a light in my head went off and I adjusted the throttle stop. 58MPH the rest of the way home!

I adjusted the stop under the pedal today and saw (maybe) a little improvement.

When it is cold it runs as well as it ever has. Then something goes wrong when it gets hot. It just dies and won't start for 10 minutes. Then it runs a bit and dies. This trouble started when I first bypassed the FDC and messed with the governor. Right now I have the Smoke Stop Cam all the way back and am doing all the adjustments with the Droop Screw.

The next thing I am going to try is disassemble the governor and look for something sticky. The truck is a '66 and the engine has about 400 hr., so it shouldn't be too worn down.