First of all I am new to the site. I have read many other posts and tried what seems to be everyones problems that they have had. I have a 2001 2500 HD 4x4 with an allison. I bought the truck with the problem and thought that it would and should be a simple fix. My truck is like everyone elses. You hit a hill and through the truck into a lug and it goes into limp mode and kicks the P0093 code. All 8 injectors have been replaced within the last 4,000 miles. I replaced the FPRV and still no change. I can drive the truck and kick the light on, on demand. I also replaced the fuel filter with a GM fuel filter because I read how picky they are on their filters. Still no change. The truck is completely stock. I have bought a bully dog power pup for the truck and you can even install it and the truck makes no extra power even before the light kicks on. I will not even puff any smoke on the high setting. This thing is about to drive me crazy!!! Bought the truck hoping to get by with a cheap and simple fix but still no luck. Any ideas now?

 

My guess is going to be a new cp3 is in order... You covered all the other bases and no luck.

 

Thats what I am afraid of. If no other advice anyone know where a trusted supplier for these are at for a good price and quality?

 

Your need to check injector return first. Just because they where replaced doesn't mean anything. When the truck is hot, shut if off and try and restart. Does it start right back up or dose it crank for a while.

 

The truck starts fine everytime. No matter what the condition is. It can be cold, hot, or even set for a couple of days and it starts no different. Truck always starts good. You never see it puff any smoke of any color. I have owned a couple of these trucks and this one has been a real stumper for me.

 

a little late but maybe it will help... my computer program shows the DTC P0093 code as "Fuel System Large Leak Detected" ... from the sounds of it, you already knew that... keep us posted

 

Merchant Automotive
Duramax Injection Pump LB7

 

Well I have a friend that has the GM service program on his computer. It pointed all things working off of the crank position sensor. I pulled mine out and it came apart as soon as I pulled the bolt out of it. Replaced it yesterday and of course still no luck. Another friend of mine was having the same problem and he had a fuel line collapsing on the rubber part that comes up and over the driver side valve cover. Checked my truck and of course it was partially crimped. Put Vice grips on it to hold it open and still drive it down the road and still kicking the POO93 code. My next try is going to be the injection pump I guess. It is going to be an expensive stabb in the dark. Anyway to diagnos the injection pump and be for sure that is what it is. How do you measure the return rate to the tank?

 

hey you fast im just two weeks new to site as well so hey im no diesel mech but the last few weeks have forced me to learn a bunch. any way you probably need a tech 2 scan tool to check return rates. if you cant get your hands on one dealer or shop can check for half or one hour shop rate.if you do take it in make sure to ask about all yuor test resaults, tag can be vauge.get them to drive it while it is hooked up and monitor through out accelleration. hey again im far from expert but hope this helps. oh ya took mine in they say ineed a new cp3 ouch, kind of strange cause i get p1093 not the 0093 and my truck dosent go into limp mode ? idk guess ill have to bite the bullet and hope it works, ill let ya know

 

Thanks for the information. I just went and bit the bullet and coughed up $800 for an injection pump. I really hope that this works. If this doesn't cure it I will be one sick puppy. I have been over the truck top to bottom and this is what I am finally down too. It is suppose to be here tomorrow so hopefully I will have some good results to post on here when I get done. I have tried all of the little tips and tricks these websites show and found most of my problems to be as they said they were but still no luck. Still kicks the POO93 code everytime. Thanks for all of the help and I will post back when the injection pump is installed.