Maybe somebody can help me out. I have a built motor with a KB on top. Their's a 3 inch upper on the KB and a 6lb lower. I changed the plugs, fuel pumps, injectors(55s), and fuel filter. Right now I have a mail order chip until I can save up enough money for a dyno tune. The problem is when there's boost at low RPMs' (under 1800) the truck skips and acts like it's going to fall on it's face. No noise, pinging or rattling just missing. Once it's over 2000 RPM the truck feels very strong. Is this detonation? If not is this a tuning issue? Oh yea i've checked the spark plugs and they seem okay. Just looking for some addvice.

Thanks Mike

 

That is basically the same pulley size that I run. I have recently regapped my plugs from .028 to .032 and it feels much stronger. Mine also doesn't feel super strong unles I stomp on the gas. I think it has to do with the 2600 stall PI converter. Mine doesn't detonate with 93 octane and the base timing is 12.5° on the mail order diablo chip.

 

First thing I would think would be spark plugs. You may not have the right heat range, and/or gap of plug. Secondly, with a mail order tune it could be running pig rich in that lower RPM band. Besides, don't cut yourself short running a MAIL ORDER chip on that built engine w/ KB on top. Why not spend another 400$ and not risk the mail order chip possibly not tuned perfectly for your application? Im sure you have a good amount of money in that setup and theres no reason to risk it... after what you spent on the motor/blower, 400$ can't possibly be too much more. Just my 2 cents.

-Mike

 

Fuel pump?

Sounds like a low speed issue I had... the "nipple" (heh) was cracked at the low speed pump. Replaced and working fine.

 

mecca
I agree with you completely that is why the truck has been sitting most of the time. The truck is definently going to a tuner as soon as possible. I'm ready to rip up some assfault.

Thanks for the help
Mike

 

Which one is the lowspeed pump. Short tube or long tube.

 

Following my experience in Miami a couple weeks ago with Willie the master tuner I have learned that basic programs need fine tuning for KB's, it is that simple.

Personally I wouldn't install a chip with a KB or a Works unless my L was sitting on a Dyno and I could custom tune that chip.

I agree with Mecca, you are talking about a insignificant investment to do it right, especially considering you have built engine with the KB!

My opinion of course.

D-Day

 

I aprechiate(sp) your opinon

Mike

 

You are positively correct, Dan......too many mail order chips are too fat or are leaning out our motors.....with a KB, proper tuning becomes even more critical.....Good Luck, Mike