1999 Saturn SC1 misfire

DORNASS1

MEMBER
1999 SATURN SC1
4 CYL
FWD
AUTOMATIC
145,000 MILES

Possible misfire-- jerky when engine is running, and loss of power from stop to start, tail pipe caked in black sut, change fouled spark plugs corrected for 10 days- check plugs no fouling, changed o2 sensor-- no change-- used fuel additive no change--- I figure next move is injectors, my dad says could be clogged catalytic converter. Problem is I need my car and have $3 to waste on any one solution that does not fix the problem, the rest should go to the one solution that will get me rolling correctly again--- where to guys?

Friday, October 23rd, 2009 AT 5:00 PM

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

Take your dad's advise and check the rest below:

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

Was this

answer

helpful?

Yes

No

-1

Friday, October 23rd, 2009 AT 6:21 PM