Perkins 403 f-15 Issues in a Wacker 3001 dumper

[robammerman]

Hey folks! I'm new here. I've got a Perkins 403 f-15 engine that has me stumped. The initial complaint was the slow loss of power. Pulling any kind of hill in high range, the thing just about stops. If you wind it up and put the hydraulics over relief, it will just about kill it too. Found the DPF was masked. Pulled it and had it cooked. No change. Found the turbo was on it's way out. Probably what masked the DPF. Replaced it. No change. I was getting an intermittent code on Perkins EST 733-3 Engine rack position sensor, voltage high. Replaced it. The code no longer comes back. The unit has new fuel filters and a new low pressure fuel pump. Ran the unit off of a different fuel source to eliminate the lines coming from the tank. Had the injection pump tested and verified. Adjusted the valve lash. Each cylinder has 400lbs of compression. I am running out of ideas for a solution to this low power issue. Anything you can see that I'm missing? Any input is appreciated!

 

[heymccall]

Did you bypass the water separator when running off temporary fuel source?
If it has this water separator, remove the whole unit to your work bench, after labeling the hose locations.
When removing the bottom bowl, there needs to be an O-ring (letter "E") in the center recess (about 1inch OD) of the bowl top. It has been left out many times by many, many people.
Next, after removing the filter, unscrew the top lid. Remove cover, square seal ring and white funnel. Now, looking at the filter stem, ensure that the outer channel is 100% debris free, even going so far as to remove the inlet fitting and running a piece of wire through there.

Assembly is the reverse.

 

[robammerman]

I did not. The customer's complaint started after he replaced fuel filters as well. I will look into that tomorrow. Your help is greatly appreciated.

 

[heymccall]

From post #11 here
https://www.heavyequipmentforums.com/threads/cat-226-fuel-problem.78929/
I recommend reading that whole thread.

 

[robammerman]

Thank you for the link. I did read all of it. I verified the o-ring is installed. I bypassed the water seperator and ran the unit. I noticed no difference on the performance. It attempted to regen and threw a failure to ignite code. I forced regen and found the ARD would go through the first stage ignition and reach 400F and attempt to open the second injector. It would abort and give the code. I tested the return fuel flow that supplies the ARD and found the flow was low. Spec is 13.6oz minimum in a min and it's only putting out 10oz in a min. It makes no difference if it is running direct from a separate fuel tank and bypassing the water separator or if it plumbed as it is from the factory. I disassembled the return side and found no blockages. I bypassed the ARD and it made no change. I'm leaning towards a fuel issue. Everything is new with factory parts or bypassed and it doesn't seem to change anything. When it's running it doesn't stumble or miss, just won't go to save its life. Maybe the new LPFP is faulty? Back to square one....

Thanks again for the well written effort. It is really appreciated!

 

[robammerman]

A third pump, ran directly from a new separate, clean fuel source that bypassed all of the filters and separators and powered from a separate 12v source still only netted 10oz in a min.

 

[robammerman]

Well, I got down to meat of the issue. It is fuel related. Found the barometric pressure sensor for the unit is only registering 5.9psi. I'm close to sea level so it should be somewhere around 14.6psi. It thinks the unit is somewhere around 26k feet and adjusting the fuel accordingly. The sensor is built into the ECM and is non repairable. The customer has been quoted and I am waiting for approval on the repair. Thanks again!