When the engine [1104] is cold it starts like an injector was out but then it smooths out and runs fine with no loss of power. It does not do this when restarted after warmed up.
My “guess” is either u have a “pissing” injector that has carbon buildup.. or.. If there’s a supply pump in the system, it’s bleeding back and your pumping air for a few minutes and then fuel.. After the initial start, the air is dispersed and she runs smooth for the rest of the day.. BUT.. tomorrow, it starts all over again..
Hi pumpguy, Thanks for getting back to me. I have 3 of these 1104 Perkins with Delphi pumps in different service. Two of them in stationary service have mechanically governed pumps and this one, the oldest one [2004] and has an electronic governor. It has never been apart, the cat 1104 setup has so far been pretty bullet proof. That said, getting it to drink has always been an issue. For some reason all manufacturers love to put an almost impossible to service screen on the in tank pickup. After a few years it invariably packs up with sludge. A few years back I replaced the stock cat feed system [intermittently-on pump/filter combo] with a large spin-on filter and a tied to run-switch always-on, electric pump. I replaced the pickup line to the filter with line big enough to allow boulders to pass through the suction line and enter the filter, where they belong. I also put a piece of clear line on the return line to see if air is getting into the feed. Unfortunately the line has yellowed so much now that I can’t see through it. I will replace that line today and see if there is any air in the system. I agree that the symptoms seem most likely to indicate air in system, but how could air get into the feed line upstream of the injector pump when shutdown? I have also observed, although only rarely, a short duration throttling up at idle?? Any ideas?
If the line has yellowed, it’s probably brittle too.. As “WE ALL KNOW”, a line can suck air and not leak.. Once u replace the line and CHANGE THE FILTER, you’ll probably see a bubble or 3.. It’s possible that the electric supply pump has a bad valve and allowing the fuel to bleed back.. You’ll see it pushing the air once u replace the clear line..(IF that’s the problem) If no air is present.. then it’s time to pull the injectors.. IMHO
Ok, I am off to get greasy. Fyi I have since found out that for a visible line, urethane tubing stays clear and supple much longer than the vinyl I am replacing. If the supply pump has a bad check I still don't understand how air can get into fuel system with the engine shut down and no combustion chamber pressure.
U don’t need to understand it.. THATS for us mekinicks to understand.. It’s your job to replace parts.. lol
Problem solved; hopefully. Here’s the scoop on how I think the air got in. Apparently, a loose hose clamp, but not loose enough to leak out, on the discharge side of the priming pump was the culprit. The electric priming pump ran without diesel leaking out, but, when the Delphi kicked in, the suction from the injector pump was great enough to pull air into the suction line around the loosely clamped hose until the return’s head pressure built up and reduced the flow. Thanks for your guidance pumpguy and good luck in sunny SC