I'm working on a CAV DPA injection pump
on a 3-cylinder Perkins diesel
. The engine
was running fine, but the IP had a pretty bad external fuel
leak. I replaced both the bleed screw assemblies and copper washers and torqued them to spec. That helped a lot but did not entirely stop the leak, which at that point appeared to be coming from where the hydraulic head
joins to the main pump
body. I removed the IP and disassembled to replace all the seals
I should point out that I'm not an amateur; I'm an airplane mechanic
and accustomed to doing things just so. However, I've been feeling very tired recently, and I should have known better than to work
on this on Sunday instead of taking a break; and it's entirely possible I did something stupid during reassembly. So...
After it was all together I put it back on the engine
(a pain) and got it running... sort of. At max throttle it will only get to 1300 rpm
with no load. With it running at 1000, I loosened the injector lines one at a time. When I did this on cylinder 2 and then 3, the RPM
dropped slightly and the engine ran rougher. When I did it on cylinder 1, the engine suddenly conked out.
Keeping in mind that I'm using more throttle than usual to get to 1000 RPM, this suggests that cylinders 2 and 3 are getting barely any fuel
while cylinder 1 is getting full fuel and almost single-handedly keeping the engine going.
Before I take the pump back off to look for anything that might be put together wrong, can anyone point to something specific that might cause uneven fuel delivery
? Is it possible that there's just air trapped in it somewhere and running it for a while will eventually work