Engine Mechanical problem
2000 Honda Passport 6 cyl Four Wheel Drive Automatic 108500 miles
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I have a 2000 Honda Passport 3.2 V6 4x4 auto transmission, 108500 miles. It has started to have a minor hesitation when I start to accelerate from a stop. This is more noticable with an aggressive start. It then seems to be okay as it accelerates untill it gets to 55 -60 mph. It is okay if I maintain the highway speed but if I try to accelerate say from 55- 65 it "stumbles' is the best way I can explain it. Only recent work was a flush of the transmission which I do about ervery 25,000 miles. This hesitation or stumble seems to be in the engine and not in the transmission, but I could be wrong. What do you think?

Possible Causes of Engine Hesitation or Stumble:

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