Hey all,

I'm considering buying a 2001 Quad cab long bed Cummins, auto. Truck has 110,000 miles, about a 2in lift, and from the gauges on the pillar i'm guessing it was chipped at some point. I spent a good part of today looking the truck over since I work in the service dept of a dealership, and found a few small things, trans pan leaking, needs fluid changes, serp belt etc etc. I noticed that the VP 44 looked fairly new so thats good. Pulled codes and got a p0234 for overboost. I also checked to make sure its not a 53 casting motor.

My question is when I took the truck out for a drive I got on the on ramp and punched it, boost gauge shot up to 30psi and the truck took off.....until 65mph then it just seemed to struggle to go any faster. Assuming the pillar gauges work egt and trans temp were normal also.

Also what is the factory boost limit?

In the glove box it says the axles are Front: 5200# DANA and Rear 6500# DANA Final gear 4.10. What axles are those? Mainly the rear DANA 70 or 80?

The truck is in great shape and a great price I just wanna make sure these are not early trans death warning signs. Any help is appreciated.

 

IIRC the factory boost seting on mine was about 20 PSI
With my juice it used a restrictor fitting in the wastegate line to bump the boost up and it may still be in there.

before I did any mods, I regularly threw the overboost code

Being a Manual guy I THINK the Auto equiped 2500 came with the Dana 70
the Manual HOs the Dana 80 and all the 3500s the Dana 80

Anybody Please correct me if I'm wrong

 

when the over boost code is set performance drops until the code is cleared, i have that code come up on mine every once in a while.........
i think factory boost is set at 28

 

I was thowing an overboost code with the superchips and replaced my boost fooler/map sensor. I haven't thrown that code with the XZT+ in 3 + years.

 

I'd suspect they played with the wastegate, and likely have larger injectors in there, you should not have been able to hit 30psi, Factory spec's are closer to the 20psi mark, PCM/ECM sees an overboost condition and starts limiting fuel,
for what its worth I have stuff in my sig, and with the gate lock wired shut I barely hit 30psi

 

with the mods in mine and the safeties in the Juice turned off Ive hit 45psi....
after that I turned the defueling safeties back on to keep from hurting something.and thats with stock injectors and no hot unlock just plain old 5x5

 

So its possible that fuel was being cut off and that's why I was having a hard time with acceleration?

It would not at all suprise me if the truck had mods on it. Who makes the waste-gate restrictors? See If I can find some so I know what to look for. Thanks for the help so far