Mechanics

98 K1500 5.7L BUCKS AND BACKFIRES??

1998 GMC Sierra • 130,000 miles

When you give it gas it bucks and backfires, take foot off pedal and idle runs good, as soon as you give it gas bucks backfires and sometime stalls but always starts up fine. What can it be?
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Petrusob
December 26, 2011.



Check the TPS and ignition timing. Also check compression. It could be a burned valve.

Rivermikerat
Dec 26, 2011.