1990 Chevy Lumina

PONYRIDER1966

MEMBER
1990 CHEVROLET LUMINA
6 CYL
2WD
AUTOMATIC
257,000 MILES

My car has been losing power sometimes and running rough sometimes. It comes out of it usually by very lightly accelerating or really stepping on it. Sometimes the check engine light comes on too but not always. It also dies once in a while but always starts right back up. Already changed fuel filter, and gas pressure regulator. What else besides fuel pump could it be?And how can I check the fuel pump?

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

The CEL coming On indicates a problem within the engine management system you need to pull the code/s from the computer.

Also could be a problem with one of 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