All right guys, I've been having problem with low boost on my truck for a while. Its a 97' 4x4 auto with the Banks power pack installed. Out of curiosity (or frustration) I disconected the waste gate and plugged the line. The truck still doesn't see over 22 lbs. of boost at maximum. The egt never gets above 1000 degrees, EVER. I've checked all the intercooler lines and boots and everything looks good. I was thinking restriction in the exhaust system (broken cat), but wouldn't that cause egt to be abnormally high? Would slipped pump timing cause this issue? I know this truck should be making a ton more power than it does. Is there anyone in the Baltimore area that would be willing to do a little "tuning" on my truck? I would be more than willing to pay someone for their time. Any help would be appreciated. TIA

MIke

 

sounds to me like you need more fuel do you have a fuel plate in it or have you moved the stock plate more boost will not make more power without more fuel

 

I know the Banks kit came with a fuel plate of some sort. All I've been able to find out about it is that it is "designed" to work with the rest of the system. I've moved the plate forward some, possibly too far forward from what I understand since 1/10" from all the way forward is optimal. Sliding the plate did absolutely nothing for power or boost though. Thanks for the reply, keep em' coming, I need all the help I can get. Thanks.

MIke

 

Well, if you want heat you need fuel. It is not a "broken" cat. If it was, the EGTs would be so high you would be afraid to find out how much boost you can get. It takes heat to power your turbo. I don't know the reason for your low egt, but, the only reason for it is either a lot of air or lack of fuel. It sounds like you should contact Banks and see what they say. On mine, I have seen 36psi boost and have yet to see the EGT over 1200*. I can pull a 6% grade at approx. 15,000 pounds and still maintain 60 mph.
Tom

 

Not very versed in the "undervalved trucks", but from reading up on here,
that very well could be the cause, or one of the causes.


phox

 

You are on a good track with the cat. On a diesel if you restrict the exhaust, you restrict the intake air at the same time, and it may not generate high EGT, but just simply run out of power with a plugged cat.

The other things to check are your flexible rubber fuel lines between the frame and the engine, and between the tank and the frame. They get porus and suck air and reduce power. Also check the electrical connection on the fuel heater to be sure it is not pulling a bit of air. Then check the overflow valve to be sure it is properly working, a weak overflow valve is like running with the fuel partially shut down.

I presume all the filters have been maintained, but some people are a bit lax with the screen in the fuel heater. It cruds up and will restrict fuel flow, and only costs about ten bucks at Cummins for a new one that lasts for years and years.

Also check the air tubes from the turbo to the intercooler, the intercooler for pin holes, and the air tubes from the intercooler to the engine.

Then check all the bolts in the top of the air horn and the plenum cover, they can get loose and let air pressure escape. Same for the fitting at the back of the AFC housing on the injection pump - it is a three way air connection with a line from the manifold to the AFC and one to the wastegate. There is a little rubber gasket that can leak and keep the AFC from opening all the way.

Lastly, pull a vacuum on the AFC and see if it is leaking a bit of air. It should be air tight, but sometimes the diaphram gets small cracks and it will not open all the way.

 

I have a stock 97 and I get 25 lbs of boost without a problem.
I have a question on the possible air leaks in the rubber fuel lines though. How would you tell if they are sucking air. Would you see a seepage of fuel when the truck is not running?
My prefilter filter on my truck had never been changed in the 197000 previous miles and there was some crud in mine. I just cleaned out the old one and put it back in.
Matador

 

MDMIKE I have a 97 12v auto with the banks power pack. I run about 36lbs of boost at full pedal and have to watch the EGT's when pulling a grade. It came with a #6 fule plate and I slid it foward just like yours. I would remove the cat weather stopped up or not. It is just a soot trap on these trucks and causes problems. I was told that by the dealler when I bought mine in 11 of 1996 new. You should have no problem with pulling power with this kit. My truck runs away from stock 04's at stop lights. Good luck with your problem.

 

Many thanks for the advice RCW and everyone else. I get frustrated when I hear of people with the same mods as myself getting so much power out of their trucks. Well, now that I have somewhere to start, its off to the shop to start diagnosing these problems and to hopefully get the cat out from under there. Thanks again for all of your help!!

MIke

 

Sorry for the double post, but Bad 6x6, I just read your sig and I see you're running a BD valve body and a Pro Torque TC. How do you like that setup? I was actually thinking about running the exact same thing, especially when I saw the price for the TC! Thanks again.

MIke

 

MDMIKE I have been very happy with my tranny after the valve body and the torque converter. I paid a little over $1100.00 for both and installed it myself about a year ago. I dont have any slippage and shifts are much firmer. The low stall speed takes a little getting use too. I have power to the ground just off idle. I can reach crusing speeds and never go over1600 rpm's. Fuel millage came up over 4 mpg (22 mpg highway now). I was told I should be good for about 350hp. if I don't abuse it. I dont plan on going higher than about 300hp.

 

Thanks for the input!! Thats exactly what I wanted to hear! Looks like thats the next mod on my list. Thanks again!

MIke

 

Well, I finally chased down my problem. All of the intercooler boots were tight, but the elbow coming out of the compressor side of the turbo was "gigged" a little sideways and allowing boost to escape. I realigned the elbow, slid the fuel plate 1/10 of an inch back from full forward and WHOA!!! 35lbs. of boost is sweet! Now I have to chase down my oil leak on the back of the injector pump and I'll be good to go. Thanks to alll for their advice! Looks like the tranny will be bombed next

Mike

 

Do you get 35lbs of boost only when the TC is locked up, or just mashing it at any speed? My truck has about a #5/6 plate, and i can only get about 22 if i just mash it when the TC is unlocked, but when its locked, ive seen 35lbs. Is this how your guys trucks do? Also, how much is the pro torque torqe converter? I would like to have a better one, but dont want to pay a fortune. Thanks

Eric

 

If I plant my foot to the floor the truck will get up to around 26 or 27 psi, but when the converter locks up, look out!! Thats when I see maximum boost. As for the Pro Torque converter, check out
www.jannettyracing.com. I'm pretty sure they sell it for around $700. Sounds like a deal to me.

MIke