Frp loss

[O6lbzccsb]

I have a 2006 lbz that's been giving me problems the last few weeks. I lose frp at acceleration from 26kpsi to 8kpsi even on stock tune. Slow starts some times. Frp jumps around at idle. I did a race fuel rail plug, filter head rebuild, new filter, bleeder screw, new fpr, and all new fuel lines in engine bay not to my tank yet. When doing my fpr I found a 2 inch hose by the cp3 that was kinked and dry rotten bad but that was replaced like I said. At a loss right now. I don't have a lift pump but I shouldn't have these problems without one. Any help would be appreciated thanks!

Sent from my SM-G930V using Tapatalk

 

[3500GMC]

I'd review your filter setup and all plumbing. It would seem you're drawing in air. As you know in stock form the CP3 does all the work drawing all it's own fuel from the tank.

 

[THEFERMANATOR]

Any codes present? Did this issue just start? When did it start? Check your fuses 1st to make sure they all are clean and tight as the fca gets it's power from a keyed on fuse source, then the ecm controls the ground to it to control the fuel pressure. Are you running a metal or plastic fuel filter? Also crawl underneath the truck and look at the fuel lines where they pass around the trans. They are known to collapse and suck closed under acceleration.

 

[O6lbzccsb]

Any codes present? Did this issue just start? When did it start? Check your fuses 1st to make sure they all are clean and tight as the fca gets it's power from a keyed on fuse source, then the ecm controls the ground to it to control the fuel pressure. Are you running a metal or plastic fuel filter? Also crawl underneath the truck and look at the fuel lines where they pass around the trans. They are known to collapse and suck closed under acceleration.

Hold it at wot for a period of time I get the 0087 low fuel rail pressure. Been a couple months. I run acdelco filters in my truck. I have rusty lines but I see no wet lines

Sent from my SM-G930V using Tapatalk

 

[THEFERMANATOR]

It's the rubber portion of the fuel lines that give issues. They are known to suck closed when the engine is demanding alot of fuel.

 

[O6lbzccsb]

It's the rubber portion of the fuel lines that give issues. They are known to suck closed when the engine is demanding alot of fuel.

I see what you mean for sure. I'm getting high frp at idle on occasions, would that be caused by air in the line? When I bleed the filter head it like foams out at times


Sent from my SM-G930V using Tapatalk

 

[THEFERMANATOR]

No, high rail pressure means the fca is going full open, or no current flow to it.

 

[O6lbzccsb]

No, high rail pressure means the fca is going full open, or no current flow to it.

Just put a brand new Bosch in it. Gotta be a line leaking somewhere huh?


Sent from my SM-G930V using Tapatalk

 

[Jaryd]

One thing I have learned working on vehicles, new parts don't always mean good parts. I've had several brand new parts not be good right out of the box. Might not be your problem but might be something to check into.

 

[THEFERMANATOR]

Just put a brand new Bosch in it. Gotta be a line leaking somewhere huh?


Sent from my SM-G930V using Tapatalk

If you're sucking air, rail pressure would drop. If rail pressure isover shooting, then you need to be checking all your electrical connections. Unless this truck has a lift pump installed on it, in which case you need to bechecking the output pressure of it as quite a few as of late have had regulator problems in there lift pumps over pressureize the system sending the rail pressure through the roof.

 

[O6lbzccsb]

Think this could be pulling air in the system?

Sent from my SM-G930V using Tapatalk

 

[Jaryd]

I would look at that line that has a bulge in it pretty close.

 

[O6lbzccsb]

I would look at that line that has a bulge in it pretty close.

The one my fingers are touching in the pic are parking brake lines i pulled them back so you could see up at the top of the tank

Sent from my SM-G930V using Tapatalk