I am working on a friends 03. He has a Banks Six Gun, Intake and exhaust, and a set of 80% gain injectors he got at Schieds Extravaganza (not sure of the brand).

The truck runs great but when cruising down the interstate the boost pressure will start surging up and down 5 to 10lbs. It really makes the the truck very rough and has to be hard on the drive line. It is a 6 spd.

What are a our options on curing this? Different Turbo?(truck needs more air anyway) scrap the six gun and get better box?

We did have a boost elbow in and was getting 55lbs of boost. Removed it and it gets 33lbs now, but surges either way.


Any help you guys have would be great

 

55psi OUT OF A STUCK TURBO!!!!!! Man you probably roasted that thing. I'd say it's time for a new turbo.

 

you got 55psi out of an HY and didn't grenade it the moment you let off the throttle?

go and buy a lotto ticket because you're a lucky bastid!! then take some of the winnings and buy a turbo

Forrest

 

I don't know a lot about the specifics of the 3rd gen trucks, but I can tell you that the surge is NOT turbo related. It is a fueling problem, not a turbo problem.

 

Ok if it is a fueling problem how do we fix it? 55 psi is what he is telling me but I have not seen it myself.

What are our options on fixing this problem??

 

I have the exact same surge, it's been there since it was stock. I have a feeling it's the fuel pressure changing but I can't yet confirm that. I am very sure it's not turbo related. I've heard rumblings that the fuel pressure sensor on the high pressure side is goofy and can only be replaced with an entire new pump. I haven't looked into this at all. It only happens to me during very light throttle crusing and very slight accelleration. At 75mph it will surge away. If I give it a bit more throttle there isn't any surge anymore but i end up going 90mph. Adding an EZ doesn't change anything, either.

Adny

 

Have you checked for leaks in the intake system? A split in an intercooler that opens up and closes or a boot that leaks might be a cause of this sort of problem. Do you hear air sounds that go along with the surge? Might also look into the throttle position sensor as well, maybe the signal is not consistant.

Also if you have the old version of the Six-Gun it was a little pipey around the 2000 rpm range. If you haven't already send it back for reprogramming. The new program is much better than the old one.

 

The six gun has been reprogramed and I don't see any leaks in the intake system. The truck ran great before the injectors with the sixgun, the problem started after the injectors were put in. Is the PCM having problems with the extra fuel?

I really need some help on this. It surges so bad that he wont drive the truck

 

What about at idle? Is it smooth? At what speeds or RPMs does it occur? Any codes? Or at what Boost level(s) will it happen at?

 

What kind of fuel pressure does he have?

 

Maybe you have a leaking injector or something like that causing uneven fueling. You might try changing the injectors back just to verify that is the problem, then get the injectors tested.

 

I would say its likely the injectors causing your troubles. And if you are putting 55 PSI through that little HY, its definitely time for a new turbo (although I don't think this is causing your surge).

Rod

 

Sheep boy!!! Long time no see. What you been doing?

 

I'll take a stab at it, how about the fuel pop off valve sitting atop of the rail, I'll bet it's leaking fuel back to the tank. Have you had a missfire yet?