LB7: Crank but no start

[2500HeavyDuty]

Tried to start the truck. the engine was a junkyard engine pulled from a running wrecked vehicle. pulled engine apart and injectors and cp3 looked to be new.

I modified the wire harness and i did accidentally cut one wire but i fixed that.

The problem is i will crank it and it will only build up 200psi in the rails. cranking rpm is 180ish.

No codes, i have swapped the FCA, Rail pressure sensor and FICM. nothing has changed after changing each of them one at a time.

Still cranks and only makes 200psi in the rails. Tried unplugging the FCA and no change in rail pressure while cranking.

Checked the large bale connectors and i have 12v going to the pink wires on both sides of the connectors. wiggled them and no change.

its late maybe i missed something. all the grounds are connected.

Besides inspecting the fprv, the next step would be to check return rates i guess. and maybe plugging the return line from the cp3 and cranking.

besides that id there anything im missing?

 

[JRODS*LB7]

Check your cp3 also mine did the same with about the same pressure and it ended up being the cp3

 

[blk smoke lb7]

Sounds like an injector is stuck open,are you seeing any white or gray smoke while cranking?

Try this pull all the glow plugs pull the inj fueses so the injectors dont fire,have some one on each side of the truck and watch the glow plug holes for mist any misting are stuck open and killing your cranking psi.I bought a 2000 mile motor that sat for 9 years with injectors in it and i tried using them and this is what i found.both back 1s were leaking.

 

[2500HeavyDuty]

I get no smoke. But I'll check and see about the injectors leaking.

 

[Kat]

Have you checked to see if you swapped the crank and cam sensor plugs?

 

[2500HeavyDuty]

Have you checked to see if you swapped the crank and cam sensor plugs?

I checked those last night, and i tried to switch them around and it's physically impossible to do cause crank sensor wires are too short to reach the cam sensor. With the harness grounded to the engine block.

I will check the wire colors and look them up to verify that they are in the right locations.

Anything to keep from doing injectors or cp3 lol

 

[2500HeavyDuty]

double checked the ckp and cmp and they are in the right locations.
i do notice an odor coming out of the engine when i crank it. i cant quite put my nose on it yet, but the glow plugs are gonna come out now.

 

[2500HeavyDuty]

Update. No fuel coming out the cylinders with glow plugs out. Checked air dog a second time and it's no longer pumping fuel.

 

[JRODS*LB7]

Update. No fuel coming out the cylinders with glow plugs out. Checked air dog a second time and it's no longer pumping fuel.

I think your cp3 should still suck fuel from tank even without ur airdog ,unless it isnt a flow thru pump?

 

[2500HeavyDuty]

I think your cp3 should still suck fuel from tank even without ur airdog ,unless it isnt a flow thru pump?

its not.
i drained the tank and bought some new fuel.

 

[2500HeavyDuty]

I must be on something I just pulled my cp3 out in 40 minutes

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[2500HeavyDuty]

I found the problem, the shaft that drives the low pressure pump in the cp3 sheared off

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[2500HeavyDuty]

Left one sheared off completely. Middle is good. Right is stripped out.

 

[JRODS*LB7]

cp3 it was:thumb:Awsome man glad you found the problem!

 

[2500HeavyDuty]

thanks for the help guys. :thumb: