SPONSORED LINKS

1990 Chevy Lumina misfire

Tiny
EZALAMO711
  • MEMBER
  • 1990 CHEVROLET LUMINA
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 86,000 MILES
Can a clogged catalytic convertor make an engine misfire? Started misfiring after driving 5-6 miles but now it starts right up and misfires, runs poor, just changed plugs and wires today. 6 months ago changed a bad injector fuel filter ignition module. I think its the cat convertor
SPONSORED LINKS
Monday, November 30th, 2009 AT 12:32 AM

1 Reply

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
To rule out the Cat do a backpressure test on the exhaust system or get a gas analysis test

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
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Monday, November 30th, 2009 AT 12:53 AM

Please login or register to post a reply.

Related Engine Misfire Content

Intermittent Misfire
VIDEO
Intermittent Misfire
Instructional repair video
Misfire Random Code P0300
GUIDE
Misfire Random Code P0300
The world of automotive diagnostics can be complex, with numerous codes and potential issues to keep track of. One of the more common engine diagnostic codes is P0300, which...
VIEW MORE

Sponsored links