Hey Everyone,
I have a 1999 Ford Contour V6 SE MTX with about 107K miles on it. For years I've used this site and NewCougar.org to do a lot of work on this car. Finally, I've run into a problem I just can't seem to solve with plain old searching. It is a little complex - so sorry for the long post.
I got a P0171 (Lean, bank 1) and rough vibrations coming from the engine and then a P0303 (Misfire on 3). I figured "Fuel, Air, Spark" and started testing.
[FONT=courier\ new]Spark[/FONT]:
[FONT=courier\ new]Air:[/FONT]
Can anyone suggest what else I can try? Would a compression test help? Any ideas appreciated and thanks in advance!
-Mark (Delkra)
I have a 1999 Ford Contour V6 SE MTX with about 107K miles on it. For years I've used this site and NewCougar.org to do a lot of work on this car. Finally, I've run into a problem I just can't seem to solve with plain old searching. It is a little complex - so sorry for the long post.
I got a P0171 (Lean, bank 1) and rough vibrations coming from the engine and then a P0303 (Misfire on 3). I figured "Fuel, Air, Spark" and started testing.
[FONT=courier\ new]Spark[/FONT]:
- Ran engine, pulled #3 wire, no change in engine RPM or behavior. Any other wire pulled caused it to noticeably stumble.
- Checked cylinder 3 for spark - yes and ouch
- Pulled spark plug 3 looked ok, but old
- replaced all plugs anyhow with new Motorcraft plugs
- Tried an old coil pack I had around - same results
- Spark seemed ok, and none of the above changed anything about how it ran. I decided to move on to Air.
[FONT=courier\ new]Air:[/FONT]
- Full cleaning of the upper and lower Intake Manifold (following usual process on the site)
- New UIM and LIM gaskets
- New Idle Air Controller gasket
- New throttle body gasket
- New EGR gasket
- While I was doing the UIM and LIM cleaning, I decided to take on a few potential Fuel issues since I had the fuel rail apart anyhow.
- New Fuel Pressure Regulator and gasket
- Replaced all fuel injectors with flow matched, reman ones from injectorrepair.com
- New fuel filter
- Fuel Pressure at Idle on rail test port: 48 lbs
- Vacuum at Idle: 18 in/hg (very steady)
- LTFT at Idle: way, way lean 25+
- STFT at Idle: 14
Can anyone suggest what else I can try? Would a compression test help? Any ideas appreciated and thanks in advance!
-Mark (Delkra)