GMC Troubleshooting Questions? Ask a Mechanic for Answers
Hello, my name is ***** ***** I am a professional here at Just Answer. I have noticed that your question was not getting a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here. If you are sure you have good spark to the spark plugs then I would start with installing a fuel pressure gauge and monitor the fuel pressure once its starts running badly to be sure its with in specs. It would also be very useful if you could scan the computer system to see if there are any fault code setting. Check these things for me and post back with the results and we can work from there.