This 05 Trailblazer was brought in for a start and then stall condition. The fuel pump was recently replaced due to a fuel leak. The customer also replaced the fuel pump relay.
I teach automotive technology. We are working on a 2005 GMC Envoy with this problem of no control circuit to the fuel pump relay. This video has been a great resource for continuing our troubleshooting journey. Thank you kindly. P.S. I wasn't bored... :)
Great find. When it won't act up it's tough. I think that I would of tried to get at all the wires that go to the ground bolts on the upper top side, may have been easier. Slice into them and get a good clean upper ground point. Thanks, I have a 2005 TB in Goderich Ontario, home of the world's largest salt mine!
Hey, bud. I hope you’re well. Mine stalling when idling in park but not in gear w/ brake pedal. Assume vac leak somewhere, not sure where as it’s not jumping out at me.. Any tips?
Scan it for codes first, check for induction leaks, check fuel pressure and watch data parameters before and during the stall. There are lots of possibilities.
Alright, I’ll offer something just to ask My friend bought a 2007 trailblazer, there’s a handful of issues. But the main thing is the engine starts, it cranks beautifully. But once it gets to idle it doesn’t hold it. It dips under idle and stalls. My mechanic friends have been suggesting vacuum leaks. If it is, how would I know?
Can you keep it from stalling by stepping on the gas pedal? If you have a vacuum leak it will be running lean and the fuel trims will be significantly positive. You could have a dirty MAF sensor or it could be under reporting the air flow at an idle. Try disconnecting the MAF connector to see how it runs. Check the canister purge valve for leakage. HTH
I would not recommend premium fuel it's actually less volatile and can contribute to starting issues cold. Have the alternator diodes tested with a lab scope.
