1997 Hummer H1 BUCKING

ARNIEM

MEMBER
1997 HUMMER H1

Engine Mechanical problem
1997 Hummer H1 V8 Four Wheel Drive 120 miles

EVERY ONCE IN A WHILE, THE ENGINE WON'T ACCELERATE BUT BUCKS. I PULL OVER, RESTART THE ENGINE & IT IS FINE

Sunday, January 17th, 2010 AT 7:16 AM

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

Hi ARNIEM, Welcome to 2carpros and TY for the donation.

Bucking/hesistating/jerking/skipping: inspect and test the probable causes below:

Oxygen sensor
Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)

Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include:

Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires
Cap and Rotor