How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask FIX IT MAN Your Own Question
FIX IT MAN, Master Technician
Category: GMC
Satisfied Customers: 17330
Experience:  Master Automotive Technician
Type Your GMC Question Here...
FIX IT MAN is online now
A new question is answered every 9 seconds

03 LB7 at highway speeds loses power almost like motor turns

Customer Question

03 LB7 at highway speeds loses power almost like motor turns off but shows rpms. Motor will also shut off but will restart after 30 minutes. CPM Fuel pump replaced with new unit but did not currect issues.
Submitted: 8 months ago.
Category: GMC
Expert:  FIX IT MAN replied 8 months ago.

Hello, my name is***** would usually scan the computer for codes first to see if it is reading any issues. Most of the time this is caused by a failure in the fuel rail pressure relief valve. These will fail and stop sealing correctly. This is by far the most common cause of this that I have seen as it allows the fuel pressure to bleed off when driving. If you need more help please let me know.

Related GMC Questions