I was a diesel tech for Mack Trucks some years back, when they had full mechanical injection similar to the FL. Once fuel is in the fuel galley of the IP, it is pressurized to 4000+ PSI. This is enough to overcome the injector springs. In hundreds of service procedures I never once had to bleed the injector lines. You do need to be sure that the fuel galley of the IP is fully bled.You have to bleed the injector lines. If there's air in the lines, it compresses, doesn't move the fuel along, and the fuel in the injector never reaches a high enough pressure to overcome the spring loaded valve in the injector. So no fuel to the cylinder.
Just loosen all the tube nuts and bleed all at the same time. Place rags around the injectors. Dish soap and water will clean up the diesel later.
You bleed all at the same time so the pressure is too low for any injector to open. Doing one at a time may cause the engine to start with a tube open and a bigger mess.
As the pressure builds in the fuel gallery near the injector tip, it forces the needle valve open. There needs to be nearly zero air in the line. Otherwise the air just compresses, no fuel moves, no spray, no start.
You may need some heat, too. If compression is low.
Give it a shot of ether.
When I was a teenager (60 years ago) my father had contracted some dozer work (Cat D8). It was winter. The engine would not start. The owner-operator decided to use ether. He blew the head right off the block.You can really mess up an engine by shooting ether into it. If you must use ether then spray it on a rag and hold the rag by the intake. Better yet fix the engine so it doesn’t need starting fluid.
Sounds like the rack is sticking .
This controls fuel flow compared to engine load .
The cold start just overrides the govoner and delivers full fuel until rpm meets throttle setting .
The throttle just determines govenor position not fuel supply .
I think the rack would have a fine coating of rust maybe from sitting with low oil and no splash feed for so long . Take the cover of and gentle move rack control leaver back and forth with a spray of WD40 or the like ,it will probably free up once run again , Cheers
Dear Reeltime:
If you study post #32 you will see that this ("The cold start just overrides the governor and delivers full fuel until rpm meets throttle setting .") is not true.
The governor is already asking for the full fuel because the motor speed (zero) is less than the throttle setting.
As per post #32, the cold start changes the "full fuel" amount (increases it beyond the normal maximum amount per injection).
Regards,
Nick
I think you are on the right train of thought. The lift pump.A couple of thoughts:
Try starting with the cold start, but during the whole startup and brief run, keep squeezing the bulb. If it runs then it would seem you have an inability to draw fuel.
When you pulled the head, did you also remove the timing gears and/or cam? I’m wondering if somehow the valves aren’t operating in concert with the piston positions. Same with the IP. Did it come off, and are you certain it is timed in concert with everything?
And the last question would be whether there is good compression.
It’s pumping fuel to the injectors - you have demonstrated that. But you have pushed fuel to the engine with the primer bulb, and it’s still possible that the IP can’t pull fuel on its own.
After that, all that’s left is poor compression, either because the rings are bad, or because there is some massive timing problem that is leaving valves open at the wrong time preventing combustion. Since you had the engine at least partially apart, I’d go back through and review everything you did.
I think you are on the right train of thought. The lift pump.
It does represent a small investment but installing a fuel pressure gauge in line just before the IP is quite helpful in diagnosing fuel issues. If you have and maintain proper pressure at the IP the issue would seem to be in a control of the pump, (rack, governor, etc).Well folks, time for an update. After considering the suggestions on the Forum and speaking with Brian at AD I went ahead and bled the injector lines. Actually I started from the temporary fuel tank and again bled everything up to and including the IP. Clear fuel all around. I loosened up all the hard line to injector fittings and cranked the engine for about thirty seconds total. Got fuel from all fittings, then snugged everything back up again.
Went for an engine start, cranked for about thirty seconds in five second bursts and..... nothing, wouldn't even spit. I did see that I was getting white vapor from the exhaust which I assumed was fuel vapor. Even though Brian said to never use the cold start I decided to try that just as I described in the first post. Sure enough just as before after five or six revolutions it fired up into a slow idle then went into full race mode for about two seconds and died. The throttle was about half speed and I never touched it when it was running.
So in a nutshell, only starts when using cold start button, idles for two or three seconds goes to full speed then dies. One other point, I'm using a fuel priming bulb between my temporary tank and the primary filter manifold. It does go soft between engine bursts. Can't remember if it is the same situation on my outboard.
Again thanks for any help of suggestions.
Psneeld, are you saying to run a line directly from the temporary tank to the IP, bypassing the fuel filters ?
Another quick update. Spoke again with Brian at AD and he recommended that I check the injection pump timing. He agrees with one of the local fishermen that if I'm getting white vapor cloud out the exhaust fuel is going through the combustion chamber but not at the exact right time. Sounds reasonable and think I will try that next.
Another quick update. Spoke again with Brian at AD and he recommended that I check the injection pump timing. He agrees with one of the local fishermen that if I'm getting white vapor cloud out the exhaust fuel is going through the combustion chamber but not at the exact right time. Sounds reasonable and think I will try that next.