755 injection pump

dennisthomas · Aug 6, 2007

I sent off my injection pump to get some new seals in the fittings where the fuel injection lines go in. All they did was replace the seals. I installed it and bleed the fuel lines all the way to the injectors. I am wondering if there is some kind of timing that needs to be done. It starts fine but it seems to be knocking and the motor shakes more than usual. when i reinstalled the pump i put the same shims in that came out. I also didnt turn over the engine or anything. If anyone has a book on the engine or any advice it would be greatly appreciated.
Dennis

jd110 · Aug 6, 2007

Dennis, the timing is done with the shims under the pump on this model. If you installed the same pump with the same amount of shims, I would think that would be correct. Is it possible that any shims were still stuck to the pump when you sent it out and they got lost? Does it sound like it is firing on all three cylinders? Try loosening one injection line at a time while the engine is running. Each line loosened should change the sound and speed of the engine about the same. If the engine does not change on any cylinder, then you may have a bad injector on that cylinder, or something could be wrong with the injection pump for that cylinder. Also if the knocking noise goes away when one line is loosened, I would suspect a bad injector also. If you do think some shims could have been lost, I can try to get the timing procedure for you.

dennisthomas · Aug 6, 2007

Thanks for the reply. I took all the shims off before i sent it in so i dont think thats the problem. The only thing that might be the problem according to your post might be Air in the lines? I thought i bled them but maybe i need to bleed a little more. ill try that tommorrow and post back what i find. I never had a problem before so it must be something i just did.