1998 Ford Taurus Hesitates, rough idle, low power

COLERICHARDSON

MEMBER
1998 FORD TAURUS
6 CYL
FWD
AUTOMATIC
135,000 MILES

I recently bought a 1998 Ford Taurus. It has the 3.0 OHV engine. I know no history on the vehicle, as I bought it to repair.

When I got it, the CEL was on, it barely idled, had poor acceleration, and was backfiring a little under load.

A scan tool showed several codes, IAT sensor out of range, MAF problem, Cam Position sensor, Misfires on basicly all cylinders, and system running lean.

I replaced the MAF and the Cam sensor, as well as changed the sparkplugs, wires, and fuel filter. The check engine light went off, and it does run better, but it still idles poorly and has slow acceleration.

It feels like it is out of time to me, but I haven't checked timing. Also, the exhaust system is somewhat damaged with most of the exhaust coming out the flex pipe (broken). I checked and it has good fuel pressure at the fuel rails.

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

Perform a backpressure test on the exhaust system to rule out catalytic converter.

Also check 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