rfolea
06-11-2014, 10:06 PM
Issue: Son was complaining his car wouldn't idle, engine just dies.
Found bad MAF sensor - replaced, engine now idles, but idles and runs rough at all speeds and temperatures (cold and hot)
Rough engine is especially noticeable when under load and acceleration.
Cleared codes, drove for 20 miles at highway speeds. No engine light the entire drive, but after I pulled into garage and sat their idling writing down a few notes, Engine light came on. Codes: 1222 (O2) and 1215 (MAF).
Engine sounds like it is running on three cylinders. Car does accelerate modestly, but not with the oomph I would expect.
What I know
---------------------
Plugs - New
Plug wires - resistance checks out fine (~$.5K ohms)
MAF - New (Was bad, new one tests out correctly, both flow and temp)
Vacuum Leaks
- Many small hoses were brittle falling apart - replaced all
- Medium sized hoses check out fine
- Air intake boot had several splits - applied RTV and duct tape to seal
IACV - Cleaned and put back - it was not stuck or gunked up
Compression - looks good (200, 190, 210, 225, manual says min is 142-156)
O2 Sensor - I doubt this is an issue because manual says it only has an impact when engine is hot, this engine runs rough at all times and temperatures.
So the O2 and MAF are telling me something is wrong with the fuel mixture and that it is particularly noticeable when sitting still at idle.
I am running out of ideas.
Does anyone think this could be a Fuel Injector issue, and if so, any suggestions on how to isolate which one without replacing all 4 (that's and expensive test)?
Audio/video of the sound the engine makes:
Audio (http://youtu.be/gxQxf49ve9g) of tail pipe during idle:
Video (http://youtu.be/WyWuEQ_HGLw) of dash while stepping on gas.
It's a little hard to hear the growl when stepping on the gas - it is more felt in the car shaking. It is not a smooth accel, it is rough.
Found bad MAF sensor - replaced, engine now idles, but idles and runs rough at all speeds and temperatures (cold and hot)
Rough engine is especially noticeable when under load and acceleration.
Cleared codes, drove for 20 miles at highway speeds. No engine light the entire drive, but after I pulled into garage and sat their idling writing down a few notes, Engine light came on. Codes: 1222 (O2) and 1215 (MAF).
Engine sounds like it is running on three cylinders. Car does accelerate modestly, but not with the oomph I would expect.
What I know
---------------------
Plugs - New
Plug wires - resistance checks out fine (~$.5K ohms)
MAF - New (Was bad, new one tests out correctly, both flow and temp)
Vacuum Leaks
- Many small hoses were brittle falling apart - replaced all
- Medium sized hoses check out fine
- Air intake boot had several splits - applied RTV and duct tape to seal
IACV - Cleaned and put back - it was not stuck or gunked up
Compression - looks good (200, 190, 210, 225, manual says min is 142-156)
O2 Sensor - I doubt this is an issue because manual says it only has an impact when engine is hot, this engine runs rough at all times and temperatures.
So the O2 and MAF are telling me something is wrong with the fuel mixture and that it is particularly noticeable when sitting still at idle.
I am running out of ideas.
Does anyone think this could be a Fuel Injector issue, and if so, any suggestions on how to isolate which one without replacing all 4 (that's and expensive test)?
Audio/video of the sound the engine makes:
Audio (http://youtu.be/gxQxf49ve9g) of tail pipe during idle:
Video (http://youtu.be/WyWuEQ_HGLw) of dash while stepping on gas.
It's a little hard to hear the growl when stepping on the gas - it is more felt in the car shaking. It is not a smooth accel, it is rough.