No rail pressure!

[dracing70]

Ok I inquired about this situation before. We bought a engine from a guy on here some months back. It was supposed to b a lmm but turned out to b a lbz. He promised the engine was low mileage and in perfect running cond. my brothers mechanic has been dicking with this thing in Florida for two weeks. They orderd a brand new wiring harness switched all the necessities and have taken apart four times and still r not getting any rail pressure. We need some help and a direction and I will also notate after all of this this persons identity for future buyers to beware. All injectors r getting signal and cp3 was even switched yet still no rail pressure. Remember they r putting a lbz into a lmm

 

[dracing70]

So apparently after the new harness was swapped out do to a hacked up harness the truck fired ran perfect for a min. Then barreled black smoke and rattled and shut down. Now it will not restart. Only getting about 400 psi of rail pressure. Cp3 s have bee switched. Getting fuel return on the rubber hose by the driver firewall but no return from the injectors. The guy that sold the engine swore the injectors were new but we think he switched them out prior to shipping the engine. Does this sound like injectors r stuck open. ..?

 

[bluecollar]

Well idk for sure but i just had a problem with my lbz pump returning fuel try pumping while cranking? But my issue seems to be rare

 

[dracing70]

Well idk for sure but i just had a problem with my lbz pump returning fuel try pumping while cranking? But my issue seems to be rare

Pumping? As in the accelerator pedal? Or the manual pump. This truck has a lift pump and it's blowing fuel up to the cp3

 

[messejme]

I Am guessing but if cam or crank sensor signal isnt present?

 

[sweetdiesel]

You could either pull the glow plugs and check for fuel blowing out
Or take a old injector line cut it and weld it shut then do each inject or individualy by placing the plug on the fuel rail

 

[dracing70]

You could either pull the glow plugs and check for fuel blowing out
Or take a old injector line cut it and weld it shut then do each inject or individualy by placing the plug on the fuel rail

Crank sensor good. I told them to plug off one ink line at a time

 

[bluecollar]

Yes mine had lift pump.. i had to pump primer while cranking. I just today swapped cp3.. i also took thethe rubber return line off my cp3 and pumped ther primer and fuel came out

 

[bluecollar]

Or your fprv

 

[dracing70]

We changed the fprv.

 

[sweetdiesel]

Could be rail sensor, low cranking voltage too

 

[dracing70]

Could be rail sensor, low cranking voltage too

Rail sensor will cause cp3 to not put out fuel???

 

[sweetdiesel]

Rail sensor will cause cp3 to not put out fuel???

If it not working/ reading properly yes

 

[Chevy1925]

Unplug the fpr if your concerned the ecm is telling it to be closed. Max rail will be commanded then.

 

[dracing70]

Unplug the fpr if your concerned the ecm is telling it to be closed. Max rail will be commanded then.

Yeah we tried unplugging the fpr. Gonna pull the injectors and have them and cp3 tested and see if one of our fellow members really burned us. He has not answered our messages in over a month.

 

[paint94979]

Yeah we tried unplugging the fpr. Gonna pull the injectors and have them and cp3 tested and see if one of our fellow members really burned us. He has not answered our messages in over a month.

Pm me, id like to know who it was that sold you this engine

 

[Chevy1925]

Damn....

 

[trevrosborough]

when the truck did run was it rough running? only reason i ask is i delt with a lbz in to lly truck before and the tone rings on the crankshaft have a diffrent number of teeth some times it would run but timming way out of wack. Most of the time it would kick a little bit every now and then an rail pressure would be low. Im not sure what the lmms are running for tone ring number of teeth cant find it anywhere but i would look in to that there easy enough to count .

 

[jkholder09]

Unplug the fpr if your concerned the ecm is telling it to be closed. Max rail will be commanded then.

with fpr unplugged it would go wide open if the barrell wasn't stuck shut.
What if the fpr is totally stuck shut?
the lmm or lbz want about 3k rail before injectors will fire

 

[sweetdiesel]

when the truck did run was it rough running? only reason i ask is i delt with a lbz in to lly truck before and the tone rings on the crankshaft have a diffrent number of teeth some times it would run but timming way out of wack. Most of the time it would kick a little bit every now and then an rail pressure would be low. Im not sure what the lmms are running for tone ring number of teeth cant find it anywhere but i would look in to that there easy enough to count .

Its worth checking but I'm 99% sure lbz and lmm are the same
Lly are different