Injection pump questions 1hz

[AndrewHadji]

In an effort not to cross post, i started this thread

Fuel pump question

Im casting a wider net to garner some more replies. Any insights to indicators of a worn IP would be appreciated... what are some common symptoms.

 

[roscoFJ73]

This was a dirty and nearly dead pump I had rebuilt. The diesel injection shop reckons it would never run but it did once it got the rpms up high enough with the easter bunny.
The main symptoms of pump wear is when the engine warms up and the pump expands(some mechanics say the 1HZ pump can expand too much)
Once an old pump has expanded it loses pressure, it may feel ok when cold. This is most noticeable in top gear when you find you are flat out at 115 kph with no load. They can also get hard to start when hot because the pump can not pressurise the fuel at cranking speed.
This is mainly from wear on the pump plunger, the end is obscured in the pic. A mechanic showed me under a bright light and magnifying glass the wear. It is very fine, I couldn't get a good pic. The other problem they get is bearing wear. This causes minute vibrations which travel along the pump and cause wear on other parts. The timer piston can be noisy as it wears out the housing.
So all those parts labelled will wear out.

 

[AndrewHadji]

Thanks, she did better today with the ac, it was the first time this season turning it on yesterday since last year so maybe it needed to get lubed because, well, shes 26 now. She did fine today, would push past 120 if i was brave enough, on hills it will slow down to about 100 and hold. Starting is no problem and no smoke. 180 k kms old, one thing i have been noticing is the main tank seems to have more oomph... might be a dirty screen in the aux tank.

 

[db3]

The only indication of a pump problem was the engine ran rough when first started, but after a couple of minutes it smoothed out and seemed to run okay. However, the truck was not driven much before the pump was removed and taken into a shop for the boost compensator install. It was then they discovered quite a bit of wear, which they attributed to low sulfur fuel. I choose to have it rebuilt and now the cold start roughness is gone.