New injection pump,still no start!

[1 Patriot-of-many]

You shouldn't have bubbles in the supply line at all. This tells me you are sucking air from somewhere, Check and tighten all hose connections and look for cracking in the lines up to the filter and to the pump. Put a clear line temporarily on the pump to return line, I'd also suspect the sensor on top of the fuel filter, those are prone to seal failure and a source for air getting into the line., put a plug in place of it with a little fuel resistant sealer on the threads. I think it's 1/4" NPT IIRC You don't need the sensor unless you have the expensive diagnostic stuff to use it. When you don't see air bubbles going through that clear line anymore, you've found the problem and I bet your truck starts. The way my luck is and I suspect yours is going to be in this case is that it never was the pump, just sucking too much air from somewhere..... Let us know how it goes

 

[05blackduramax]

1 patriot-of-many that's what iam thinking getting lots of air bubbles out of fuel filter bleeder. I'll get a plug and plug that sensor off.

 

[1 Patriot-of-many]

1 patriot-of-many that's what iam thinking getting lots of air bubbles out of fuel filter bleeder. I'll get a plug and plug that sensor off.

Next step I'd take if you still are getting air, is remove the line into the filter and out of the filter and connect them with a piece of clear tubing between them to rule out the filter canister all together and it would indicate the air is coming somewhere before the filter. And back track your way like that till you find the culprit, whether its the fuel pump on the block itself or some connection all the way back to the tank. Good luck. Let us know what you find. Hopefully something easy.

 

[05blackduramax]

Ok I'll get some clear fuel line too.

 

[1 Patriot-of-many]

Don't forget some tubing and new clamps to put them together if you have to.

 

[Action]

Do you have enough fuel in the tank?

 

[05blackduramax]

Tank is full.

 

[Stonepicker1]

Questions:
What was wrong with the old pump that you thought you had to change it?
Was the engine running before and how was it running before you changed the pump?
Why did you have to change the top of the pump with a part from the old pump?

Just seeing if I'm missing something.

 

[Action]

He probably had a 12v replacement.
Nothing to do with bubbles, but I wonder if the timing chain and gear were put back in the same place...Don't those have to come off for the IP to come out?

 

[05blackduramax]

Truck wasn't running,no fuel to injection lines,put a new pump that had the 12 volt coils on it,I used the old 24 v coils,and I put the new return valve on the old top.

 

[05blackduramax]

I didn't mess with the timing chain or gear,just pulled old pump out noted the position of the dowel pin,pulled new pump out and it was in the same position. I slid it back in and bolted it back up.

 

[Guyfang]

Did you time the pump before hand?

 

[05blackduramax]

Not sure on the timing of the pump,I did line up the timing mark on the outside of pump housing to the mark on the engine block.

 

[Guyfang]

Thats what happend to me. But once again, this was in a generator engine. I assumed the timing was right, and stuck it in. It was 180 out. I have never done a HMMWV. Ask KRED. Hes the go to guy for me. Just don't believe ANYTHING he might say about me.

 

[05blackduramax]

Guyfang, did you have alot of air bubbles?

 

[05blackduramax]

Everything I've be reading says you can't have it 180° out it's not possible only possible if you have removed timing chain and gear. There is only one way for the pump to go on with only one dowel pin hole.

 

[Guyfang]

Its been way too long since I did it to remember if there was bubbles.

Why cant it be out of time. Lets say the pump is set right, (timed) and you rotate it another time, until the dowel is in the same position. Is it still in time? That's what happened to me. The pump sent fuel to the chambers, but out of time. Engine turned over like a champ. But no fire. The pumps I installed came properly timed, (or were supposed to be properly timed) right out of the box. But sometimes they didnt come in a box. Or someone had taken it out and played with it. That's what I mean.

 

[05blackduramax]

From what I read the pump just spins 360 with the cam. If you turn the pump end with the dowl pin 180° it would not line up with the cam gear. That's what I read on the Diesel place fourm.

 

[NDT]

Sundowner9000 gave you this advice about all the bubbles you are seeing:
From the manual fuel pump to the fuel filter? No, it should be shooting out of that line extremely fast. If it put that line in a water bottle and crank, it would fill it up in 5 to 8 seconds probably. Sounds like you might have gotten lucky duramax and maybe just have a cracked fuel line sucking air or that lift pump which is reasonably cheap. I'd check from there back to tank before you swap IP

 

[Stonepicker1]

From what I read the pump just spins 360 with the cam. If you turn the pump end with the dowl pin 180° it would not line up with the cam gear. That's what I read on the Diesel place fourm.

You are correct. The 6.2 and 6.5 pump will be lined up correctly in the cam gear. I've done 6 on the HMMWV's and around 8 on the CUCV's.(and 3 on my CUCV-II's)

I know what "Gayfang" is saying....I've installed a pump on a 60KW and 30 KW generator and they were 180 out. Had to take it back off and spin it 180 and reinstall to get it to work.

This is not what your problem is..