1995 GMC Jimmy hiccupp/bucking

DEMONBOY

MEMBER
1995 GMC JIMMY
6 CYL
4WD
AUTOMATIC
160,000 MILES

My jimmy idols fine (when it's running), but when I give it gas, it hiccups/bucks, and stutters. If you try to drive it, it's like it has water in the gas. It starts to go, then it cuts out, then it goes again.

I've taken the car to 2 mechanics. Both have said that when they put it on the "machine", it doesn't register anything wrong. The check engine light never came on.

I've drained the gas, replaced the fuel pump, the fuel filter, and the spark plugs. Still, it hesitates and bucks (when it's running).

Am I missing something?

Scott

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

Check and test the following below:

Oygen Sensor
Catalytic Converter
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

Note:If it doesn't apply, disregard.