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trans slip? or engine hiccup?

4509 Views 15 Replies 4 Participants Last post by  jon72
I have an '04 LB7 with a Banks Six Gun Bundle(Ram Air, Monster Exhaust, BigHead wastegate acctuator, Six Gun Tuner w/ SpeedLoader) and before the intake and wastegate acctuator were installed the engine seemed to "hiccup" when i really got on it. I thought this was just the engine begging for more air from the stock and insufficent air filter and believed this would stop once the ram air intake was installed. After installing the intake the same thing happened. Is this my torque converter slipping or is there soemthing wrong with the motor?
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LB7's dont usually bark the turbo like an LLY dose!

Yous Sounds like it Could be doing what is refered to as Bursting, no one has really proven what causes this but most seem to beleive it a fuel supply issue and usually only happens when running high horsepower tunes, and laying on the throtle pretty good, The best fix for this would be to install a lift pump!!

DO you ever set any check engine lights?

THe Dmax dose not run any pump other that the CP3 injection pump on the engine so this pump has to draw the fuel from the tank to the engine and raise it to 20,000+ psi, under extreem fueling the cp3 cant draw enough fuel to keep its self supplied so a lift pump is added at the tank to pump the fuel to the engine!
The pumps used for this need to be low pressure(under 15psi) and high volume, if the pressure is to high it will blow up the fuel injection module.
Kennedy diesel and TTS sell great setups
Also a cheep thing to try would be to change your fuel filter, how many miles are on it?

Check out kennedy diesel. com he has some good setups or even give John a call there, i would try a new fuel filter and see if it helps the problem as it will magnify the problem if its dirty, i change my filter every other oil change(6,000 miles) to help prevent problems. Running a higher hp (chip) tune a lift pump will help no matter what, but beware running these kind of power levels will kill your trans.I think a full blown kennedy lift pump kit runs about 500 bucks and they go down in price from there and a basic wrench turner should be able to install them!!!

How much boost are you running?

Hope this helps,

PS filling out you signature under user cp with you truck and modifications will help folks here better help you !!!!!!
Fass systems work really well but there have been some problems when the fuel tank gets below 1/3 they will start sucking air!

But some of the baddest running duramaxes out there are running fass systems so im not saying the're a bad system at all, you just have to keep the tank full!

weettiddo007 said:
Im running almost 26 pounds right now. Thanks for the help, Im ordering the kit from Kennedy on monday along with a new fuel filter.
26 pounds is good, u could raise it alittle more but dont go much over 30. Over 30 psi bad things start to happen to the turbo!!!!
The kennedy pumps are a flow thru pump so your truck will run with them off and you can just turn them on when needed if you wanted, i made my own setup with a holley blue pump with my own made wireing harness using a relay and an oil psi swith so the pump will only run if the key is on and there is oil psi just like kennedys harness. The pump i used has to always be running because it will not flow thru when its off.

Also kennedys pumps are the quietest pumps out there, most of the other ones sound like a small shop vac running under the truck!!!!!!!
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