low rail pressure code

0

06dmax

slow duramax
Joined
Mar 6, 2008
Messages
13
hey need some info i have an 06lbz with ppehot on5 ppe lift pump ppe rail fitting and i try to run at the track and i loose rail pressure and the truck runs like crap what should i do to fix this
 
You need to shim your FPRV or do a race valve PPE can take of it. Do you have a lift pump? DO you know anyone with a tech II or EFI they can monitor your RP
 
I disagree there is no need for a modded CP3 with a PPE Hot. Have you checked your act and req rp
 
I'm not sayin Wicked is wrong they make some well... Wicked ass pumps but I just have a hard time seein you needin a modded reg or pump.
 
Mine did the same with the same setup during dyno pulls. I never fixed it before going to EFI. 300 tune pulls a lot of fuel; might look into an in-tank pickup. Modded regulator might have helped also but not sure.
 
Big Block 88 said:
I disagree there is no need for a modded CP3 with a PPE Hot. Have you checked your act and req rp
Click to expand...

Well I disagree with you, any tune 100hp or more above stock will benefit from CP3 modifications. The term "need" becomes clearly evident once you realize the benefits of a properly modified CP3.
 
we put a ppe on a LBZ today on level 6 and it is throwing the 0087 code which is low rail pressure correct? We didnt put the shims in the rail yet will that help? When at full throttle the rail pressure drops to 13K. Im not a duramax guy so im not sure what they run at WOT or just idleing. Any help would be appreciated...I was just trying to figure out if it could be the cp3 or if it just might need a lift pump to give the cp3 more fuel. Im sure you duramax guys know more about it than I do. Thanks
 
If it doesn't have a lift pump that's for sure the problem. Level 5 made more power than 6 on mine. Get a lift pump first and then shim if it still codes.
 
make sure the race valve is seated correctly and TIGHT. is there any fuel on or around the back of the rail where you installed the valve? try changing the fuelfilter also as they tend to get gumbed up fast...

SYUPDAWG- yes you need to either shim the FPRV or install the ppe race valve, and a lift pump for the bigger tunes
 
I had the exact same setup on my 07 lbz. Had a airdog 150, ppe racevalve, an ppe on level 4. My truck would throw the code ALL the time, even with the slightest grade or a hard down shift. I ended up takeing the ppe valve out an shimming the factory valve to ppe spec. Truck ran perfect an has yet to throw the 0087 code.
 
I had a problem with the gold coating on the PPE valve flaking off and it caused it not to seat. Ruined TS for me last year
 
Fuel rail

My 06 lbz did the the samething. I shimed the rail then put a race plug in and neither fixed it. The driver side rail was bad I fixed it and have put 70k mile on truck since. To check it for sure pull the hose off the back of the driverside rail and run fuel pressure up you will see if the releaf valve is bad in about 2 sec. I have a hot+2, 3000 turbo, 95 Fass , ATS coplit, and precision converter.
 
also install a cheap pressure gauge on either the top of the fuel filter housing or u can remove the schrader valve test port and install it to that( which i dont recommend because i ****ed my **** uo doing that, but seem to be the only who had problems doing that route) to adapt to the fuel filter housing youll need this 10mm 1.5 to 1/8 npt Shop


my liftpump wouldnt push any fuel even tho i could hear the motor running (that part throw me off to thinking i had another problem
 
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