Starting Issue

hwystar

New member
2
0
0
MN
2010 G6 with 2.4. When engine is cold will not start unless I push gas pedal to the floor. After starting will start again without WOT. Runs good once started. Replaced the following:
MAF, Both O2 sensors, purge solenoid, spark plugs, air filter.

Fuel pressure 55psi and holds at 53psi after 5 minutes being shut down. Code P0172. LTFT= -19.5. STFT ranges from -7 to +3. Pulled plugs and all show rich not just one or two. MAP value good. CAT ok. Temp sensor good. Smoke test no Vacuum leak. No exhaust leak found.

Would appreciate any suggestions.
 

melsg5

Staff member
SUSTAINING MEMBER
18,595
14
38
Inspect all vacuum and PCV hoses, replace if necessary
Check the fuel injectors, they may be dirty. Use fuel injector cleaner or get them professionally cleaned/replaced.
Check for an exhaust leak before the first oxygen sensor.
Check the fuel pressure regulator vacuum line for gasoline, if present, replace it.
Are you using the standard paper air filter?
 

hwystar

New member
2
0
0
MN
I did smoke test for Vacuum leak and no leaks found. I do run standard filter. No exhaust leak prior to O2 sensor. I have run injector cleaner through it. Cannot check the Pressure regulator vacuum line since there isn't one. The regulator is in the tank part of the Fuel pump. I figure the regulator is good since it holds fuel pressure. I am really stumped with this one.
 

melsg5

Staff member
SUSTAINING MEMBER
18,595
14
38
You seem to have covered all the basics, if it's a high mileage engine it could be the injectors.
 
Your email address will not be publicly visible. We will only use it to contact you to confirm your post.
Top