how to fix miss

1997 CHEVROLET SUBURBAN
180,000 MILES
Avatar
BIGSA
  • MEMBER
  • 1 POST
5.7 vortec is missing alot going up mountains then runs ok back and forth up long grades. misses on flat to but not as much .runs like a champ one min .then like a dog the next.
Oct 2, 2011 at 3:40 PM
Advertisement
Avatar
HMAC300
  • CERTIFIED EXPERT
  • 48,601 POSTS
check your fuel pressure and do all electrical ignition checks. this can be low fuel pressure as well as electrcal or injector. if you have csi type fuel devlivery then it should be 60-66 psi. if you have sfi(port fuel) then it should be 56-62psi. if it's beleow those levels that may cause your problem.
Oct 2, 2011 at 6:13 PM