Same problem on my 4-10, a runaway diesel and diesel fuel in sump:
- The dipstick oil level was something like 1/8 to 1/4 inch per hour of running
- In North East of Canada
a community of 800 people.
- I removed the lift
pump and checked, OK, no holes in the diaphragm
- Local diesel injector shop (the only expert in 400 miles) says it's the injector pump.
- Of course they (one persons shop) are busy to remove the injector pump. But suggests a fellow who repairs
- This guy comes over and we look over and talk over the situation. He's busy as well but provides good advise.
- BTW both fellow tell me it's tricky cause to remove on this engine cause one has to maintain the alignment between the engine's gears and the pump's gears or it's a big job to get it back into alignment. Funny
, the manual that came with the boat says simply to unbolt it!
- I, myself, followed the manual and removed the injector pipes and pump. Piece of cake.
- The local shop sends injector pump and lift
pump away to be rebuilt.
- $1,700 later, pump and lift pump returned.
- Lift pump not rebuilt!
- Re-installed injector pump, piece of cake, bled the line and away she goes. But same problem!
- Cracking back the nut (loosening) each injector (nut holding pipe from injector pump going into the injector) did not change the engine sound or speed.
- So after wasting 10 days, off sailing we go and a few ports
later found a retired diesel mechanic
who says likely a leaky injector.
- I removed injectors, he tested and found one injector spewing too much diesel, he recalibrates on his homemade injector tester (a hand pump and a pressure guage) , I reinstall (used new copper washers).
- Problem solved
It was a leaky injector.
The injectors are held on the the block by bar with a hole for the top of the injector and with a nut on a stud on each end of the bar. The nuts have to be tightened evenly to seat the injector squarely in the cylinder. Had quite a problem with one cylinder, and we likely over tightened to get it to seat.
BTW - The previous I had a leak at an injector (front one) and it would not stop by tightening. Local shop said torquer her down (meaning put some muscle on it). I did and cracked the pipe. I was in Buffalo and closest new pipe is in New Jersey
(TransAtlantic Diesel). Overnight delivery
. The pipe is about a foot long with 8 different bends! Took me 8 hours to get the old one out without disassembling anything else. Now I can do it in 15 minutes! Normal.