Jump to content
  • Sign up for FREE! Become a GM-Trucks.com Member Today!

    In 20 seconds you can become part of the worlds largest and oldest community discussing General Motors, Chevrolet and GMC branded pickups, crossovers, and SUVs. From buying research to owner support, join 1.5 MILLION GM Truck Enthusiasts every month who use GM-Trucks.com as a daily part of their ownership experience. 

2008 gmc 2500 reduce engine power

Recommended Posts

First time posting here, I’ve got a 2008 gmc 2500 6.0l, very very long story short I did a variable valve timing delete , mild summit cam, headers and injectors, I’ve had this thing to the tuner a dozen times and when the truck is running it runs like a bat out of hell but that’s only when it’s not going into reduce engine power randomly, I’ve replaced the wiring that goes to the throttle position sensor , the Throttle position sensor twice, gas pedal. My tuner  can’t seem to help and he’s a reputable intelligent guy, if I could figure out how to control the 6l90 transmission I’d do a carb swap on this thing………… the only thing I’ve been able to figure out is when I’m driving down the road and it goes into reduce power I’ll pull over and relieve the fuel pressure by pushing the schrader valve on the fuel rail and it comes out of reduce power every time, I don’t know if that has anything to do with my problem ? Fuel pressure 60psi.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

By using this site, you agree to our Terms of Use.