1998 Chevy Silverado

JAYCASTEEL

MEMBER
1998 CHEVROLET SILVERADO
V8
4WD
AUTOMATIC
117,000 MILES

2 things are wrong
1. While driving at highway speeds the engine seems to increase 200 rpm for a second of two then go back to about 1800 rpm, especially when cold.
2. When I accel. Quickly up to highway speeds to quickly blend in with traffic and it gets into overdrive it seems to act like its flooded, I have to get of the gas for about 5 to 10 seconds to clear it out then it's fine.
Within the year I have replaced the fuel filter, fuel pump a lifetime one, sparkplugs and wires, and the spider(the whole fuel injectors and tubing and meterbase.

HELP!

Thanks
ine.

2 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Check and test the following 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