803a fuel pump issues

[jmenende]

Hey guys I have an issue maybe some of you can help me with. My 803a did not want to start and I tracked the problem down to a stuck fuel pump.
So i took out all 4 one by one to avoid mixing them and put them back once i made sure the lever and piston moved freely. The issue is I do not get adecuate pressure off each pump outlet. The more i tighten the top nut the less fuel comes out till it stops (its possible i assembled it in the worng order but i cant find the blowout to confirm. Im pointing at the top nut that contains a barrel, spring, plunger, large washer and two small washers. thia part unscrews from the pump body). The shims and pumps were left in the exact order. My pump model is 751-41174a lister petter. Any hints?

 

[Ray70]

Hello, Those are the high pressure metering pumps. How are you checking the fuel volume and what exactly are you experiencing?
When cranking you will only get a tiny spurt of high pressure fuel from each pump once every 2 revolutions of the motor.
Please elaborate on how you are testing and what you are seeing as you tighten down the top nut.

 

[jmenende]

I dont have a pressure gauge to test it at this moment but the flow is not enough to start the engine. If i finger tight the metering pumps i do see a gush of fuel coming out every two revolutions but not enough to call it a jet. I removed all the pumps again and reinstalled to make sure the lever went into the rack slot but the problem persists. I will take a video and post it.

 

[Ray70]

You should not be expecting a jet by any means. You will barely get a tiny little dribble ( although it would be at high pressure if you were able to fully contain it. But the volume is so small that you will barely notice any volume at all. I think you may be expecting too much and may actually be OK.

 

[jmenende]

Ok, here are two videos. One is with the pump finger tight amd the other shows the flow when its loose till i tighten it by hand to finger tight. I have updated the links.
https://drive.google.com/file/d/1SqnQGzT3ecKN-_VSwzgrL2lkgsCVWd2a/view?usp=sharing, https://drive.google.com/file/d/1Sw5i3dpwjP1i90DYj_odpjTPrF5QHjcR/view?usp=sharing

 

[jmenende]

Were you able to see my videos?

 

[Screwface]

Were you able to see my videos?

I'm having the same issues on my 802, did you ever get this resolved?

 

[jmenende]

I'm having the same issues on my 802, did you ever get this resolved?

If I recall, i took the pump out and made sure it was nice and loose. Put it back together and made sure the it was correctly seated with the rack springing back into place when the shutoff lever was moved. I cranked till fuel started coming out and it worked. If the rack seems sluggish, you might have some varnished up pumps that need a good cleaning. Either take them out and parts cleaner with them or run some diluted atf fluid mixed with diesel for an hour under load and that should do the trick.