1988 Chevy Truck misses under load

1988 CHEVROLET TRUCK
200,000 MILES • V8 • 4WD • MANUAL
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KBL9697
  • MEMBER
  • 1 POST
fuel filter is new, 350 engine, throttle body injection will chug and miss under load when engine warms up but runs fine at idle.Feels like electrical to me, but who knows. Engine light does not come on.
Sep 14, 2009 at 9:57 PM
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RASMATAZ
  • CAR REPAIR CONTRIBUTOR
  • 75,992 POSTS
Could be caused by the following:

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
Sep 15, 2009 at 5:25 AM
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