Air fuel ratios are richer then before?

[talontsiboy24]

Its wierd ever since this warmup weather rolled threw like 40s n 50s my air fuel ratios at wot are 10.1-10.2? when it was 20f and below its 10.7-11.1 around there is it the weather u think? I dont have a boost leak and i have all new couplers and there really tight on! Im gonna do a wot pull tomorrow night when its colder and see if they go back to where they were then i will know its the weather.

 

[gofer]

Update your profile modifications list, then we'll see what we can do as far as helping you. Right now I'd be taking shots in the dark not knowing exactly whats on the car.

 

[98GSXtacy]

Like Gofer said, we need to know what's on your car and everything to help narrowing things down. This has to be Gofer's favorite forum on this whole site .

 

[talontsiboy24]

Update your profile modifications list, then we'll see what we can do as far as helping you. Right now I'd be taking shots in the dark not knowing exactly whats on the car.

I have:
6bolt with arp bolts threwout mls headgasket stock cams
Big 16g ported n clipped
ported 2g mani
ported o2 housing
3" dp 3" exhaust
pte 680cc injectors
rewired walbro 190
93 octane
2g mafs 3" intake
ngk bpr7es ngk me77 wires
3" core fmic kit with 2.5" piping
oil catch can

when the temperature was colder outside like in the 20s and below wot 10.7-11.1 air fuel ratios now that its 40f-50f its 10.1-.10.2?

 

[gofer]

What are you using to tune the car with?

 

[talontsiboy24]

What are you using to tune the car with?

the only changes i did was switch one of the mbc vacuum lines from a 1/8" to a 5/32" because the 5/32" was the size that suppose to be on there 1/8" was so tiny and had to force the hell out of it to go on so i knew it was the wrong size! also there was a really short vacuum line going from the fuel rail to the tee that connects to the intake mani and boost gauge i switched that to 5/32" also cause it was incorrect but i dont see how those tiny changes couldve messed with my air fuel ratios? Other then this i have all new couplers and there on tight!

I just have a custom erpom ecu chip for my mods now but i do plan on getting dsmlink the chip has:8000rpm rev limit,680cc injector compensation and deadtime, 2g mas compensation, custom fuel and timing maps. Octane reset, fuel cut removed.

 

[williillii]

My car seems to be doing something similar...I tuned it to about 11.8:1 in 30* weather. Then I went out the next day and all of a sudden its running at 11.3:1. That night, it went back to 11.7-11.8. Today its back at 11.3.

I have a feeling there is something else going on though. I do have one boost leak at the intake manifold near cyl 4...

 

[gofer]

Other then this i have all new couplers and there on tight!.

Just because the couplers are tight doesn't mean you don't have any boost leaks, especially now since you did all that stuff with the vacuum lines. Do a boost leak test, don't just tighten up some couplers and call it a day, do the test and see how many places are pissing air. Boost leaks will create a rich condition going into boost because the ECU is trying to shoot for a target AFR, say 11:1, seeing "x" amount of air. If you've got a boost leak that "x" amount of air the ECU thinks is making it to the cylinders is escaping somewhere, so then you create a richer condition in the engine than what the ECU is shooting for.

 

[talontsiboy24]

My car seems to be doing something similar...I tuned it to about 11.8:1 in 30* weather. Then I went out the next day and all of a sudden its running at 11.3:1. That night, it went back to 11.7-11.8. Today its back at 11.3.

I have a feeling there is something else going on though. I do have one boost leak at the intake manifold near cyl 4...

yea im waiting to see what my air fuel ratios are tonight since the temps will be in the 20s and thats when i was seeing nice air fuel ratios so i will let you guys know if its not that then yea time to do a bl test again.

Just because the couplers are tight doesn't mean you don't have any boost leaks, especially now since you did all that stuff with the vacuum lines. Do a boost leak test, don't just tighten up some couplers and call it a day, do the test and see how many places are pissing air. Boost leaks will create a rich condition going into boost because the ECU is trying to shoot for a target AFR, say 11:1, seeing "x" amount of air. If you've got a boost leak that "x" amount of air the ECU thinks is making it to the cylinders is escaping somewhere, so then you create a richer condition in the engine than what the ECU is shooting for.

Another thing is the vacuum line going to the wastegate on the turbo had a tear right where it connects to the nipple and i was still seeing 10.7-11.1 i fixed that so i shouldnt be running richer so this is wierd but yea i will keep you guys updated on what i find.

 

[talontsiboy24]

I went for a drive last night temps were in the 20s and what do u know i do a wot pull and my air fuel ratios went back up so i guess it is the weather so when spring comes i will have to retune it. Another thing is when i get on it but not fully and hit 20psi my gauge shows 10.0 but when i put the pedal to the medal wot at 22-24psi my wideband goes to 10.7-11.1 around there?

 

[Hubbell91Tsi]

Yes weather is going to affect the tune but not that much, thats why everyone loves driving these cars in cold weather because they make so much more power. Cold Air = Dense Air = Lots of Power!

 

[talontsiboy24]

Yes weather is going to affect the tune but not that much, thats why everyone loves driving these cars in cold weather because they make so much more power. Cold Air = Dense Air = Lots of Power!

True im gonna miss this cold weather but not the krazy snow that we got this yr!