1995 Nissan Truck Perplexing hesitation problem

KEITHINTX

MEMBER
1995 NISSAN TRUCK
6 CYL
4WD
MANUAL
15,000 MILES

I'm hoping I can get an answer to this problem as it has me somewhat stumped as to the cause.

I was having a problem with the motor hesitating upon acceleration (you could see the tachometer bouncing). The spark plugs, fuel filter and plug wires were all replaced, the contacts inside the distributor cap were cleaned, and the main serpentine belt was replaced.

The vehicle starts fine, and runs okay on idle, and has no performance issues until the engine warms up, after maybe 10 to 15 minutes. After this, any attempt to accelerate is met with hesitation and a burning smell. Once the vehicle returns to idle, however, it runs fine with a few minor skips.

I've had several people examine the problem and was told it was everything from a clogged screen inside the oil pan (not enough oil flow), a dead oil pump, and possibly a timing belt issue. Is any of this even close, or is the problem more sinister in nature?

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

Hi eithintx, Welcome to 2carpros and TY for the donation and selecting us as your auto repair site. Feel free to ask questions at anytime-

I've had several people examine the problem and was told it was everything from a clogged screen inside the oil pan (not enough oil flow), a dead oil pump, This one is okay if the engine is knocking-but has nothing to do with your hesistation problem> I strongly recommend you check and test the following items 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