Help: Need Help , ASAP, Rail pressure problem

[paint94979]

I haven't yet , but it is the list of things to try , going to start with checking the return rate for both the injectors and CP3's , then try Joshes Idea of the "switch" , and if i havent found it by then , I with pull the belt and dual cp3 wiring and test the pump in the valley . If i wasnt so short on time wouldnt be too worried about getting it figured out , but i need this sorted out by next weekend or else it is pointless going to the race in AZ with it the way it is , I think i will get it figured out in time though .

no reason to suspect it is sucking in air right? you had the entire engine apart changed lots of fuel related components and yet you are still seeing the same weird PSI drop? seems odd doesn't it? i am an idiot but it sure seems like it must be injectors because that is one of the same common denominators...

 

[TrentNell]

no reason to suspect it is sucking in air right? you had the entire engine apart changed lots of fuel related components and yet you are still seeing the same weird PSI drop? seems odd doesn't it? i am an idiot but it sure seems like it must be injectors because that is one of the same common denominators...

the only thing is , the problem is the same, but if you look at both logs they are a fair bit different when you look at it , it is worse now , and though i wasnt logging , the problem didn't seem to be there the first time i drove the truck it was breaking the tires loose and extremely powerful , now it is def lacking what it had , and now the turbo's are actually functioning properly but haven't gotten a good test since , that is the main reason i am questioning the belt even though it doesn't quite make since .

 

[MMLMM]

It's not in the rail like are trucks Mike it's in a spliter block behind the cp3 in the valey

doh...damn lb7 guys lol. when he said bottle test I started thinking on a LLY+ train of thought

Shit Trent I have no idea, maybe it is something w/ the injectors...Crap like this always seems to come up just before an event.



The dual fueler control seem to be working correct? How long did the pressure regulators sit on a shelve without fuel going thru them?

 

[S Phinney]

You are using the fuel cell now right? Pickup is feeding from the bottom of the cell? Return test would be the most helpful for you Trent right now. Fuel returning will not always be conclusive with balance rates either. Best of luck I'm anxious to hear how well it runs for you.

 

[TrentNell]

Well pulled the belt off last night , cleanned the pully . re-installed belt and checked it by turning the pully with a ratchet with the belt on , it isnt slipping now , well its slipping as much as i would call normal , after all it wont be solid enough to turn the motor over or anything . Didnt see eany oil or anything on the belt or other pully's though .

 

[fishsmith]

I had to change the configuration of my belt to keep it from slipping. I added an extra idler pulley in a different location. I would have to look at all that crap in the shop floor to say for sure where I put it at but I can say that it fixed my problem. Not sure if that might help you.

 

[05smoker]

Any possibility you are sucking air in the tank from where your pickup is in the front? Not sure if that could be the case or not but I remember the conversation from when we saw pics of it and figured I'd throw it out there. Be easy to see if it were that on a dyno where the truck is sitting still and you are going wide open with it.

Any other ways to test injectors for excessive return without a tech 2? I know on LLY and newer you can use a heat gun on the return but that obviously won't work here. Speaking from experience of cracking injector bodies on LB7s, just a thought.

Ed

 

[JoshH]

Any possibility you are sucking air in the tank from where your pickup is in the front? Not sure if that could be the case or not but I remember the conversation from when we saw pics of it and figured I'd throw it out there. Be easy to see if it were that on a dyno where the truck is sitting still and you are going wide open with it.

Any other ways to test injectors for excessive return without a tech 2? I know on LLY and newer you can use a heat gun on the return but that obviously won't work here. Speaking from experience of cracking injector bodies on LB7s, just a thought.

Ed

I think he turned it around.

 

[TrentNell]

I had to change the configuration of my belt to keep it from slipping. I added an extra idler pulley in a different location. I would have to look at all that crap in the shop floor to say for sure where I put it at but I can say that it fixed my problem. Not sure if that might help you.

I will have to see what come from my other tests and go from there . I never had a problem with it slipping before but ......

I think he turned it around.

I did Josh , just wasnt worth messing with . I am hoping to get to drive it when i get home from work and see if cleaning the pully helped , if not the return rate tests will commence . I need a diagnoses by this weekend so i can fix it so time is against me at the moment .

 

[TrentNell]

Any possibility you are sucking air in the tank from where your pickup is in the front? Not sure if that could be the case or not but I remember the conversation from when we saw pics of it and figured I'd throw it out there. Be easy to see if it were that on a dyno where the truck is sitting still and you are going wide open with it.

Any other ways to test injectors for excessive return without a tech 2? I know on LLY and newer you can use a heat gun on the return but that obviously won't work here. Speaking from experience of cracking injector bodies on LB7s, just a thought.

Ed

I tested it in the shop while not moving ,and even doing it that way , basically a burn out just bstaging the truck building boost it still dropped rail .

 

[JoshH]

Have you logged regulator current? What about supply pressure at the CP3?

 

[TrentNell]

Have you logged regulator current? What about supply pressure at the CP3?

No , I havent logged current , I probably should though . I still need to get a lift pump gage , i just cant see how it could be draining it down , it has a massive amount of flow feeding the system .

 

[JoshH]

I'm sure it's fine. Just trying to rule things out.

 

[TrentNell]

I'm sure it's fine. Just trying to rule things out.

No I agree josh , untill i prove other wise everything is suspect , thats what diagnosing should be , suspect everything then check things off as you test and verify there function , at the end you will find it if the diagnosing is methodical .

 

[TrentNell]

Problem still there , went for a spin , took 5 logs and all the same ,I re-grounded the CP3 right to the battery this time and installed a lift pump gage , feed pressure at idle is 9 psi ,drops to 5-6 psi and no lower, so supply is ruled out , belt and cp3 grounding also . hopefully i can test the return a little later tonight , its looking more towards injector/injectors . a log from tonight ,forgot to log reg current though .

 

[paint94979]

Problem still there , went for a spin , took 5 logs and all the same ,I re-grounded the CP3 right to the battery this time and installed a lift pump gage , feed pressure at idle is 9 psi ,drops to 5-6 psi and no lower, so supply is ruled out , belt and cp3 grounding also . hopefully i can test the return a little later tonight , its looking more towards injector/injectors . a log from tonight ,forgot to log reg current though .

sorry to hear this Trent who's modified injectors are they?

 

[RPM Motorsports]

Is it possible the pumps are cavitating trying to push so much fuel? I did not read all the post's, so sorry if it was covered!

 

[paint94979]

Is it possible the pumps are cavitating trying to push so much fuel? I did not read all the post's, so sorry if it was covered!

trent IIRC ran a FASS pump prior to his current setup and the issues are still the same

 

[TrentNell]

trent IIRC ran a FASS pump prior to his current setup and the issues are still the same

yep , and supply/ lift pump pressure never went blow 5 psi on my tests tonight.

 

[TrentNell]

sorry to hear this Trent who's modified injectors are they?

They are BigDipper tips , but if it is an injector issue , the bodies will be bad not tips so ........