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Discussion Starter #1
I think I'm going to need a new injection pump soon. I've been having some issues that I thought were just some old fuel lines letting in air. Maybe a Pressure Relief Valve? But anyway - I did some maintenance and upgrades. I have installed a Fass lift pump to start with. I also installed a PPE pressure reliefe Valve. And I've replaced all of the soft lines on top of the engine. But I'm still getting a P1093 and P1094 code. My injector balance rates are great so I don't think it's an injector issue.

I have a new FPR sitting on my desk - but I've been hesitant to install that if my whole injection pump may be bad. I suppose it's decision time.
 

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What engine are we talking about here, LB7, LLY, LBZ?

You can fill out your trucks description in the User CP area and put that information in there so we know what model we're dealing with
 

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Discussion Starter #3
LB7, sorry I thought I had all that in there at one time.
 

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What are the symptoms that you're having? Extended crank, hard to start, low rail pressure, dropping rail pressure under throttle? Even with the balance rates showing good, there are other keys that factor in to injector health that you can't get a read on with a scan tool
 

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Discussion Starter #5
What are the symptoms that you're having? Extended crank, hard to start, low rail pressure, dropping rail pressure under throttle? Even with the balance rates showing good, there are other keys that factor in to injector health that you can't get a read on with a scan tool
Initially I had nothing major - just the codes and no 'giddy up' at WOT. I just felt flat. Then I started to lose prime a bit if I parked on a hill. And so between all of that I put on a lift pump and replaced all the rubber lines. It still doesn't start right up perfectly, but it doesn't seem too bad, either. I've got no smoke through my exhaust (at idle) so I don't *think* injectors are bad.

I don't have a way to measure actual rail pressure unless DashCommand can do it and I just don't realize it.
 

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Do you know how old or how many miles the injectors have on them?

It could be high return rates on the injectors causing an extended crank, as well as falling flat at WOT. If the injectors are returning too much fuel, the cp3 has a hard time building enough rail pressure to start the engine, and then has to work very hard to keep the rail pressure up during higher fuel demand

Not saying this IS the problem, but its a heavy possibility
 

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Discussion Starter #7
Do you know how old or how many miles the injectors have on them?

It could be high return rates on the injectors causing an extended crank, as well as falling flat at WOT. If the injectors are returning too much fuel, the cp3 has a hard time building enough rail pressure to start the engine, and then has to work very hard to keep the rail pressure up during higher fuel demand

Not saying this IS the problem, but its a heavy possibility
I do not know how many miles/years these have on them. However, I do know that this engine was torn down and rebuilt with forged internals (about 3 years ago) so I can imagine that the injectors were done at around the same time.
 

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Discussion Starter #8
Update - I'm in the process of taking out my injection pump. I've got the four bolts loose from the front of the engine and all of the fuel lines off. I'm trying to pry out the pump gently but it's not really budging. I can see it moving a little, but it's not coming out. I really don't want to break anything.

Is there some trick that I'm missing? Or is it just apply a little more force? Will hand turning the crank (and by association the pump gear) help loosen it up any?
 
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