[avis]

Hope someone can point me in the right direction on this. I had the Superdiesel lift pump and filter installed last week and now the truck has a hesitation. It happens when I get on the go pedel quickly. It has done it a few times from a standing start and is real bad while cruising down the road. If I get on it more than half throttle it wants to hesitate and then take off like at beast. I've tried with the pumps on and off. It feels like a old quadrajet carb hesitation. It acts like it's getting too much diesel poured in at one time. The Superdiesel set up is a flow through, so when they are off, it should only be running normal fuel rates. Anybody have any suggestions on where to begin the trouble shooting? Thanks!

 

[TIM Z]

I'd like to know too!

 

[avis]

C'mon guys no suggestions. Now the hesitation and surging is through out the entire run. The surging during the run is minor but it's there. I checked the injector timing and it was 35 at wide open throttle. The fuel delivery was at 24000. Any direction on where I need to look next? I'm new at this game and I'm completely lost on the Diesel end. No silent codes and no SES light. Thanks for any help!

 

[Diesel Tech]

If you have 35 degrees timing at WOT you have way to much timing and that in and of itself will cause surgeing.

 

[[email protected]]

Avis,
How many miles are on your truck? who installed the lift pump? Did they use a relay?

Steve,
He said he had the lift pump installed and then started having the problem. How does the timing have anything to do with his problem when it was not prestent before the install of the lift pump? What a BS answer....

 

[ripmf666]

Hey Avis is the 35 deg with the ppe stacked with your edge still also did you put a clean factory filter on with the lift pump install, Not sure how super diesels setup works i'm only running the edelbrock 1792 and no extra filters other then that were running close to the same setup

 

[avis]

I have 2000 miles on the truck. It does it with the pump on or off. Is the main injector degrees the same as the timing? I checked it via the PPE Data scan. I also checked the pump to make sure it was running and by passed the boost switch. It comes on without the boost switch connected. If I run it without the pump I get 22000 psi and 24000 with it on. Could it be the factory fuel filter? Although it seems to be getting plenty of fuel. I'm lost on this one! I called Mike at SuperDiesel and he gave me the check list to do and everything checked out. I've got him stumped as well. It seems to be getting plenty of fuel and no check engine light or silent codes. This is gonna be a good one to figure out. I also tried it with boost and with no boost. With no boost it is more pronounced. But it will kill you if you tried to pass someone. It has a serious delay like 1-1000 2-1000 nothing and then it goes.

 

[avis]

No, I took the Edge off . It had retarded timing with it on. Damn this truck is driving me to drink! Help me out guys!

 

[avis]

I didn't put a factory fuel filter on at the time. I started to do it and the filter wrench wouldn't fit. I plan to do it this week, I have a wrench ordered. Is it possible to have a flow porblem with it reading so close to demanded fuel? It's within 2000 psi delivered opposed to what the truck desires.

 

[ripmf666]

so I take it you lost some of the rattle you were talkin to me in pm's about, I would try a new fuel filter with teh lift pump install mybe you sucked something up from the talk also have you been getting your fuel from the same place no water in fuel, by chance did you do the intank pickup with #10 feed line if so mtbe something came unhooked in tank give me a call im off work and just sitting around should still have my #

 

[Super Diesel]

Tell me the distance between the fittings where they are hooked up to the fuel line and I will send something to bypass the pump to see if that is what is cousing the problem. Got to start the process of elimination to narrow down what is causing it.

 

[avis]

Mike, I will call you before 2 o clock my time tomorrow. I will get what I need to bypass the pump and try that after I talk to you. If you will just tell me what I need tomorrow. I don't think it will be a fuel delivery problem but at this point I open to anything. It seemed to be getting enough fuel to the motor, according to the psi #s.Thanks!

 

[[email protected]]

Is it possible you are sucking air into the system? Are all the fittings tight? Is you PRV shimmed?

 

[avis]

Dan, I sent you a PM

 

[JOHNBOY]

What is your pressure at the factory filter? Do you know? Putting to much pressure to FICM can cause all kinds of weirdness.

 

[ripmf666]

Hey johnboy good thought but the lbz does not have the fuel cooled ficm

 

[JOHNBOY]

ahh thanks. I know on LB7s and LLYs to much pressure can cause all kinds of weirdness.

 

[Dozerhand]

Please don't flame and attack me, but my truck will hesitate on acceleration if the filters are not primed all the way.

 

[avis]

How long does the hesitation go on for if not primed all the way? Does it go for days or just a few miles? It could be a option to look at, but mine has done this for 200 miles.

 

[Super Diesel]

The pump is only a 7psi unit.