Ok, I just got my truck running about a week ago. It's a 5.3, stock bottom end, PAC springs, Edelbrock proflo intake, 65 lb/hr injectors, GT45 turbo. It idles great, has good driveability around town, but if I try to get on it, it doesnt go! seems like anything over 1/3 throttle stops pulling and making power. If i floor it, it will rev and spool up, but doesn't go like it should. I'm using HPTuners to tune, but I'm still learning and just would like a possible point in the right direction...thanks!

I have a couple scans, but not sure how to post them.

#ad

 

Is all the torque management stuff turned off? I know when we first started tuning my old Turbo 370ci it would just pull all the timing as soon as it saw boost... I believe it was the torque management that we forgot to turn off.

Nice looking truck btw. any more photos of it?

Jay

 

nice project. As stated timing is a good direction to look. Crank sensor can also cause a "default" low timing in a stock pcm scenario and may apply to your setup. I ran into a "Crank wheel out of sync" problem with a factory pcm reprogram

 

Thanks for the info guys!
I think I got it figured out. I did a ton of reading and have got my timing map close, turned off all torque management, and found my eboost had the gate sensitivity set at 3psi letting all my goodness out! I fixed all that and am making a solid 8psi so far. This truck weighs nothing, so it really hauls, and i'm looking to run it up to 15lbs when i get it all tuned up.

 

Im curious if your still running the maf or converted to speed density? If your still on the maf you need to max out the maf fail frequency as high as it can go and jack up the maf to tp correlation table really high. That table looks at airflow vs how far the throttle is open and when it sees crazy boosted airflow it will go into 4 cyl limp mode and do weird stuff.

If you want to, send me your HPT file so i can look at it and ill point you in the right direction. Its not too difficult but getting a base tune down but how the program responds to changes is intimidating at first. Some tables read funny and you have to "read between the lines" to figure out how the GM engineers looked at it.

This content is protected

 

Thanks bud, I'll shoot you a file. I'm SD and the truck is running good, but I feel like it should be stronger. At WOT i'm seeing 10.8 AFR and i have my gate set at 10 psi, but it won't pull past 8psi.