Pontiac G8 Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
36 Posts
Discussion Starter · #1 ·
Getting these codes on my G8 GXP, stock other than rotofab CAI and Livernois Stage 2 tune. I have a crappy Konnwei KW310 reader that doesn't have export functionality, but can do live PID tracking. So far i've noticed LONGFT2 is pegged at +24.2 at idle, reduces slightly under load to +9-13, reduces to 0 when coasting and 0 throttle. Tried cleaning and tightening CAI, fuel system cleaner. The p0204 went away, but still getting very lean condition and high LONGFT2 values.

Anything else I should look at to troubleshoot on the reader? Was thinking it is most likely upstream 02 sensor on passenger side, bad #4 fuel injector, or vaccum leak, or a combination.

Thanks for any advice!
 

·
Premium Member
Joined
·
6,898 Posts
Both injector four and bank two oxygen sensor are on the passenger side and would verify the injector is functioning properly.
 
  • Like
Reactions: Urmanjoshie

·
Registered
2009 G8 GT
Joined
·
361 Posts
Second the injector.
 
  • Like
Reactions: Urmanjoshie

·
Registered
Joined
·
36 Posts
Discussion Starter · #4 ·
Thanks, so you're both saying it is most likely a bad injector? Easy enough to replace and find out.
 

·
Premium Member
Joined
·
4,522 Posts
Fuel injectors must have a meter resistance reading of 11 to 14 ohms. Anything outside of that range (like 2 to 3 ohms above or below) an your looking at trouble. A while back I had #3 injector fail big time an it had a resistance value of 25 ohms. So it only takes a very small ohms change to wipe out an injector.
 

·
Registered
Joined
·
36 Posts
Discussion Starter · #6 ·
Fuel injectors must have a meter resistance reading of 11 to 14 ohms. Anything outside of that range (like 2 to 3 ohms above or below) an your looking at trouble. A while back I had #3 injector fail big time an it had a resistance value of 25 ohms. So it only takes a very small ohms change to wipe out an injector.
Checked #4 injector and it read 11.5 ohms, so a bit low but right in the range expected. However, the connector was VERY loose on the injector. I cleaned them, and reconnected. It isn't seating fully for some reason but I got it as tight as I could. I also noticed that I can turn the injector with a little bit of force, unlike the other 7 that won't budge at all. Tried using a long screwdriver and listening to the injector fire, and it sounded a bit more loose than the others (pretty scientific term, haha.)

The good news...started it up and the trim went down to +5-9, still a bit higher than bank 1, but otherwise it's running like normal again. No CEL since.

I'm thinking of replacing the injector anyway, what do you guys think? Anything else I should check?
 

·
Premium Member
Joined
·
6,898 Posts
Ensure there isn't any sort of debris, contaminant or the seal preventing the wiring harness connector from full seating on the injector. Otherwise, may want to consider splicing in a new connector/pigtail just to be sure. By the way, current mileage?
 
  • Like
Reactions: Urmanjoshie

·
Registered
Joined
·
36 Posts
Discussion Starter · #8 ·
Ensure there isn't any sort of debris, contaminant or the seal preventing the wiring harness connector from full seating on the injector. Otherwise, may want to consider splicing in a new connector/pigtail just to be sure. By the way, current mileage?
Good call, I'll look a bit more closely and see what's going on. 87k miles.
 

·
Premium Member
Joined
·
6,898 Posts
For what it's worth, Rock Auto carriers both the fuel injector and fuel injector connector. Standard should be fine on the connector, but would go AcDelco perchance Bosch on the fuel injector.
 

·
Registered
2009 G8 GT
Joined
·
361 Posts
Definetly replace that pigtail connector, did you check the ohms on the other injectors? was this one way different than the other 7, if so I would replace it.
 

·
Registered
Joined
·
36 Posts
Discussion Starter · #11 ·
Definetly replace that pigtail connector, did you check the ohms on the other injectors? was this one way different than the other 7, if so I would replace it.
I did check the resistance on the others, ranged from 11.2-12.5 so it was right in range. I ended up taking it to the shop with a Bosch injector just in case. They found that the plastic lock on the connector was stuck (I missed this somehow), so when we fixed that it seated perfectly. Also checked for vacuum leaks and didn't find anything. My LTFT2 is now perfect as far as I can tell from my cheap OBD2 reader, between -2 and +2. I just don't know how the connector came off or became loose in the first place? That is a mystery.
 

·
Registered
2009 G8 GT
Joined
·
361 Posts
Damn chipmunks, hopefully that takes care of the issue.
 

·
Premium Member
Joined
·
6,898 Posts
At some point in time, perhaps the connector was either removed or disturbed. At any rate, at least it appears to have been a relatively simple fix.
 
1 - 13 of 13 Posts
Top