First start, can't prime fuel system.

C

Cord

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Oct 4, 2006
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Got everything buttoned up last night on the new engine. Went to prime the fuel system and it's taking forever! I'm getting small bubbles, but no real quantity of fuel. I'm trying to bleed at the fuel filter, the supply line and the return valve. Always the same result, small bubbles, but no really quantity of fuel. The best that I ever got, was a good dribble from the supply line, but I can't repeat it. I did get some fuel to spurt from the #1 injector, but again can't repeat it. Sometimes the truck does try to fire, but then it stops. The best that I've gotten is one good puff of smoke and the sound of a partial cylinder ignition. This is after 2 1/2 hours of priming! I'm fairly certain my fuel lines are tight, but I'll check them again this morning. Any other ideas of what can be checked?

The engine was rebuilt with a aftermarket cam and the fuel pump was installed by the builder.
 
I'm not familiar with your exact truck, but I would pressurize the fuel tank with a blow gun (maybe through a vent line???). If you have any leaks they will start pissing fuel. If you don't you will very quickly purge all the air in the fuel delivery system. If there is no fuel flow, crack the supply line directly at the injection pump to relieve air pressure.

Once I did this and had verified good fuel flow at the pump I would crack the injector lines and spin the engine over until the lines were all spurting well, then tighten them and fire it as you normally would.

When you pressurize the tank you may find something stupid, like a leaky filter or similar.

Good luck.




On Edit:

Don't go crazy and pop the tank. Just give it a little air, lol.
 
When you do get it running, I would be careful with that 'lil turbo with your mods. Might get a tad warm.
 
haha. yeah they get a little toasty. i had the setup in my sig with my old WH1C and that would peg the pyro before the boost gauge. pulled 65 lbs of boost and somewhere around 2000* EGTs. but my #4 cylinder blew up... no doubt from getting hot and somewhat high mileage. i'd watch the right foot when you get it back together.

Anyway, I have had this happen before and pressurizing the tank does work, as long as you don't go to crazy. it will be a two person job most likely though. just crack the line at your injection pump and then have a buddy pressurize the tank with a blow gun and fuel should start the spew out. tighten that up then try to bleed the injectors normally, and you should be good to go.
 
We'll have to see what the temps are. My signature is a mix of my old combination and the new engine. I need to get some more specs from the builder so I can complete it. Because my timing was conservative with my old setup, I didn't have any temp issues, but definitely needed more air. Next project though...

Anyways, we got it running. It was a case of me focusing on the problem and not trying to find the cause. Guess it was just too late and we were tired. Anyways, after posting, I felt that I really needed to check the fuel connections. Sure enough the line going into the fuel pump was a turn loose. Guess it was sucking air. Too bad I didn't think of that before. Would have saved me several hours of frustration.
 
Cord said:
We'll have to see what the temps are. My signature is a mix of my old combination and the new engine. I need to get some more specs from the builder so I can complete it. Because my timing was conservative with my old setup, I didn't have any temp issues, but definitely needed more air. Next project though...

Anyways, we got it running. It was a case of me focusing on the problem and not trying to find the cause. Guess it was just too late and we were tired. Anyways, after posting, I felt that I really needed to check the fuel connections. Sure enough the line going into the fuel pump was a turn loose. Guess it was sucking air. Too bad I didn't think of that before. Would have saved me several hours of frustration.
Click to expand...

If you had pressurized the tank, fuel would have been dripping on the ground right there, making it very easy to see.

Just for future reference.
 
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