1999 Chevy Truck

1999 CHEVROLET TRUCK
268,000 MILES • V8 • 2WD • AUTOMATIC
Avatar
LGCASA
  • MEMBER
  • 5 POSTS
gets worst as the day gets warmer. Engine pings under load mod to hard accell or up hill. backfire when de accell or down hill. and when cruising at about 70 mph and rpm 2200- 2500 truck will buck and cause the drive shaft to ping.
Jan 15, 2009 at 8:42 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.
Advertisement
Avatar
JACOBANDNICKOLAS
  • CAR REPAIR CONTRIBUTOR
  • 110,190 POSTS
Hi:
The easiest thing to try is better gas. If that doesn't help, move to the knock sensor. If you have a backfire on deceleration, check for exhaust leaks or engine vacuum leaks.

Let me know what you find.

Joe
Jan 22, 2009 at 3:48 PM
Advertisement
Avatar
LGCASA
  • MEMBER
  • 5 POSTS
I was suspecting the timeing chain. A friend of mine has a analyzer that is able to read the cam sensor. THe info i got is its should be 0 degrees to -2. and it should stay there all throught the RPM range. Its all over the scale from +6 to -16. I haven't taken it apart yet if i keep my speed down its ok. Do i understand this properly.am i possible on the right trake?
Jan 22, 2009 at 9:29 PM
Avatar
JACOBANDNICKOLAS
  • CAR REPAIR CONTRIBUTOR
  • 110,190 POSTS
It sounds like you are on the right track. You may want to check the pick up coil in the distributor too. there may be a problem there too.

Joe
Jan 23, 2009 at 3:26 PM
Avatar
LGCASA
  • MEMBER
  • 5 POSTS
I'll double check that. thanks for your help
Gil
Jan 26, 2009 at 4:48 PM
Avatar
LGCASA
  • MEMBER
  • 5 POSTS
Found the problem . the harmonic balancer came loose and the crank sensor reluctor was rocking and ate the key notch out a whole key width the chain and cam sprocket were pretty worn also. replaced these parts and it runs like new.
Feb 8, 2009 at 3:39 PM