p0093 sucks

[poo93fu]

So i have the good ol first gen dirty max and the sucker sure likes that p0093 code. Chased it over and over again and i can not find the fuel system leak that trips the phantom code. took the fuel filter housing off and checked it and it holds pressure however the fuel filter housing pump never actually gets completely stiff no matter how many times you pump it. Shimmed the fprv. injectors were replaced under warranty. No fuel in the oil. Sure would think that a fuel leak would make a good mess that could be detected. Something is fishy here and i cant place it.

 

[Kat]

Moved here..

I am wondering if the crack in the housing is so small you can't actually see it. LB7's are notorious for cracks in the housing. If you pump it enough it should get hard.

 

[fctry286]

if you do end up needing a housing I have one with the Wif delete plug and billet bleed plug. maybe check your rubber hoses that connect to the housing those things are always dry rotting. it could have a small crack and since there is no pressure, only vaccum pulling the fuel it could cause the code. happen to me. went to the stealer and replaced them. they are not the expensive. like $10 or something a piece.

 

[Burn Down]

Im with Kat it should pump up hard. Something else that can cause low fuel pressure is high injector return rates. The balance rates can be perfect as well, but the injector is still returning to much fuel. However I think its something in your filter head, try using a hose plier on the discharge line of the filter head, see if it will pump hard then. If it does your problem is not filter head...

 

[poo93fu]

Ya sorry I wasn't clear but I actually took the housing off and capped one end and applied pressure through the other and it held pressure like it should. But when I put my pump to the line headed away from where the housing is it would not hold pressure. I could apply 17 pounds and just watch the needle drop and I could here air escaping into the tank.

 

[poo93fu]

Do you know what the return rates on the injectors should be?

 

[Burn Down]

Post 287 is for the LB7
http://www.duramaxdiesels.com/forum/showthread.php?t=6199&page=20

 

[McRat]

Moved here..

... If you pump it enough it should get hard.

Or perhaps try adding 1mg of Viagra per tank when filling up.

 

[Evan@InglewoodTrans]

Or perhaps try adding 1mg of Viagra per tank when filling up.

:spit:

 

[Burn Down]

lol

 

[BLKLMM]

:roflmao:

 

[Kat]

Or perhaps try adding 1mg of Viagra per tank when filling up.

 

[poo93fu]

Put a test on the truck today and the desired fuel was like 175 mpa and the actual was at like 80 while pulling a hill right before the code would drop. idk what mpa really is. A measurement system somehow? pascals. ha idk

 

[blk smoke lb7]

I did a 01 with that code this summer and its a process you have to go threw to eliminate everything else and if you cant find anything if all is as it should be then your cp3 is bad.The truck i had here had brand new injectors installed and a brand new fprv installed so those were ruled out.I changed the fpr,no change.I did a vacum test on the test port and the vacum was good.After that it was concluded the cp3 was bad.installed a good used cp3=no more code P0093.unless your injectors have been changed very recently you should do a bottle test and see how much they are returning to rule them out.Good luck and let us know how it does.


Also welcome to DD

 

[poo93fu]

Sounds good to me. Thanks a bunch.

Does anyone happen to know where to get some 2500 hudred badges and an allison badge?

 

[MACKIN]

Oops Pats in trouble now!

 

[super diesel]

You may want to check the needle valve in the FPRV that you shimmed. I've found a few over the years that had cracks running in them that let the pressure out and drained back down through the return line. This can cause headaches. May not be it, but it is a problem that I have found with them, but its rare.

 

[poo93fu]

Ya i need to take it back off i guess and look at it closer. I had it off and shimmed it and like an idiot didn't really look to hard at the needle and the seat to make sure everything is ok. Are they generally pretty small cracks?

 

[AKlowriderZ71]

Any updates on this?