Mechanics

CHEVY HESITATION

1999 Chevrolet Suburban

Engine Performance problem
1999 Chevy Suburban V8 Four Wheel Drive Automatic 172000 miles

My Suburban is giving me a some trouble. When starting out down the road everything is great until I hit about 40-45 mph then it starts bucking, or hesitating. This lasts until I hit about 55 mph. If I gun it it won't hesitate. Once I am past 55 it runs out fine. Seems to only be an issue when applying the throttle gradually. I have replaced the plugs and wires, just replaced the starter (was told this issue could be starter related), and have run Berryman B-12 through the fuel system. I am at a loss of what to try next. Sure could use some help.

Thank you
Avatar
Wegs67
November 29, 2008.



I am having same issue, mine too is a 1999 chevy suburban, just hit 117k miles. It has random bouts with trouble starting. Hesitates at different speeds. After about 20 mins of driving you will hear and feel a thunk from rear of vehicle.

Tiny
Rjstager
Jul 28, 2012.
Trying to solve the same problem. No answers for you, but if you found a solution please share! My question title, if you search for it, is "1998 Chevrolet Suburban My K2500 Chevy 7.4L runs fine cold."

Tiny
Dmccrack
Oct 12, 2012.
SOUNDS LIKE THE T.P.S. THROTTLE POSITION SENSOR IS WEARING OUT.

Tiny
Cobys68chevy
Oct 13, 2012.