1995 GMC C1500 pumping the gas to keep it running

THETRUEREBEL

MEMBER
1995 GMC C1500
V8
2WD
AUTOMATIC
92,000 MILES

I was on the interstate and it was running fine and all of a sudden it started to chug and it would only keep running if I pumped the gas pedal like a heavy metal drummer. So I pulled over and had a friend start it while I worked the throttle from under the hood and the two injectors seemed to be spitting fuel fine so I tried driving it the mile back to the house and it died. No longer was I able to drum it down the road and I had to call a tow truck. No leaks, no clunking no rattling and no check engine lite.

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

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