[MattLef]

Ive been doing some searching but cant seem to find a definitive answer.

A little back story on the truck. I could usually get it to start on ether but now it wont.

I was suggested that it was more than likely a cp3. So I replaced the cp3 and I still cant get it to start. A buddy came over and helped me bleed the injectors and got it to fire up. The thing drove great the rest of the day and I thought it was over.

Well the next morning rolls around and it wont start again. Get my buddy to help me out again on bleeding the injectors and it doesnt seem to work. So we keep bleeding and eventually it starts.

Im thinking it never needed a cp3 and has a different issue.

btw my lift pump is working and I have 9-10psi with it on.

Also is the lift pump suppose to hold pressure when its off because mine will bleed off.

 

[mthomp1]

It's drawing air in somewhere in the fuel system. When that happens, it drains all the fuel in the lines back to the tank. Bleed it again and park it nose down. If it starts as it should tomorrow morning, this is your problem.

 

[dodgerammer97]

think you have a air leak

check ur primer bulb it may be bad check forum for air leak in fuel lines hopefully others will chime in

 

[MattLef]

Are lift pump pressure and rail pressure suppose to maintain even with the truck not running.

My low side pressure will bleed off in a matter or seconds ans on the computer my rail pressure seems to drop instantly when the engine is turned off.

 

[mthomp1]

The system should stay primed, but there will be no pressure behind the fuel. As I said, your fuel system is allowing air in somewhere. A surefire way of knowing is to try the method I mentioned in my previous post. And just an FYI, this particular forum is for 1st gen. 12 valves, not common rails.

 

[1st gen pipeliner]

What year truck are we talking about here? 12v 1st gen = ve, 12v 2nd gen = p7100, 24v 2nd gen = vp, 24v 3rd gen common rail=cp3.

 

[Guest]

yea this is making no sense here.

 

[Fritzcat]

You may check the water drain. It may let air in when not under pressure. May twist it to improve seat. First thing in the mourning, work the lever on lift pump a few times to push fuel to and air out of injector pump, to see if its helps.

 

[MattLef]

Yeah I totally posted in the wrong forum sorry guys. If a moderator could move this that would be great.

Truck parked down hill and it didn't matter. Still wont start, I'm sure it will if I have someone help me bleed the injectors again.

 

[mthomp1]

Yeah I totally posted in the wrong forum sorry guys. If a moderator could move this that would be great.

Truck parked down hill and it didn't matter. Still wont start, I'm sure it will if I have someone help me bleed the injectors again.

It'll only work if the truck is primed as it should be. So once you get it bled again, park it nose down again. In the meantime, look for any obvious fuel leaks while the truck is running. I fought a very similar problem on my 24 valve truck. Turned out to be fuel leaking from the filter housing an drawing in air overnight.

 

[MattLef]

I just went over the whole truck and there are absolutely no fuel leaks anywhere. So is the only thing left is the fuel pressure relief on top of the rail or the check valve in the lift pump?

The lift pump is stock too.

 

[mthomp1]

I just went over the whole truck and there are absolutely no fuel leaks anywhere. So is the only thing left is the fuel pressure relief on top of the rail or the check valve in the lift pump?

The lift pump is stock too.

The return side of the fuel system (I think) can draw in air without leaking any fuel. The supply side will leak when it's drawing in air. I've never dealt with a common rail, but I'd think that if the lift pump was the culprit, it would leak since it's on the supply side.