I am at my wits end of trying to figure this trouble out I am having with my 97 GMC Yukon 5.7 vortec. I had the engine rebuilt by a local shop after being diagnosed with a spun bottonm bearing. Ever since getting the truck back I have had an intermitten sputter/hesitation while driving @ all speeds. I was advised if the cylinders were bored a bit that I should use high octane gas. The truck then recently sat for the last year without use. I just replaced the oil with Mobil 1 synthetic 5w30, and puralator oil filter, plugs,wires,cap,rotor,air filter, and fuel filter. When the engine idles I can hear a very little hesitation within not noticieable to the average person. While driving I will experience hesitation/small backfires intermittenly. I had the truck put on a scan 2 weeks ago and there wa intermitten misses on cylinder 3 and 5. This was before all the new parts. Truck runs better but not the same. I was advised by my mechanic that there are problems with those fuel injectors in this year truck and that my injectors should be relaced with the new revised injectors from GM. I had the entire spyder system replaced a few years back but dont want to believe they have to be done again. I could be wrong. Mecahanic suppossedly called a GM guy and he told him to replace the injectors or try NAPA fuel injector cleaner only to see if it resolves the problem. I only have approx 4,000 miles on the rebuilt engine. Please help me to see what else it could be. Is there any known problems such as this with these trucks and engines?
Sep 25, 2009 at 11:04 PM
