My car used to run a PERFECT 12.0 AFR on e85 last month. Now I had to retune it because it was spiking over 13.0! The entire log is leaner everywhere. Fuel trims were great last time I checked, but that shouldn't effect open loop fueling anyway, should it? All the FPR lines are good and intact too. This is on the same tank of e85 too, I dont drive it much. Car is a IX.

Thanks

 

You're probably going to have to give more information than that. About the only thing that's changed in the last month is the weather, maybe your temp correction is way off?

 

If you had Lean Spool turned off before, maybe you accidentally turned it back on?

 

Temperature has not changed that much at all. Probably about 8 degrees cooler now than it was last tune. Lean Spool was disabled then, and still is. Thanks

This is my friends car BTW. Incase anyone was wandering how I know.

 

The ethanol content changed at your e85 pump station. As far as I can tell, whenever the pump in my area has a higher ethanol content it becomes leaner, and if the content becomes lower it makes my car richer. Although leaner conditions could also be caused by other things ie. clogged injectors.

 

 

 

I believe he will be looking into that. Sounds like that may very well be the case. They are PTE 1200's.

 

Does he have a catch can installed? For some reason, I noticed that the #1 injector is always more 'gunky' than the others. My theory is that it is caused by the oil blow by from the crankcase vent that gets routed directly to the intake manifold right next to the #1 injector. Although, I am not 100% that its the real reason why it gets gunky but it is definitely possible.

 

Yes I have a catch can.

 

Oh ok, also mind me asking what wideband are you using and did you recalibrate it(if its a permanent install wideband)?

 

LC1 and yes

 

I was going to suggest the ethanol content may have changed, but he said it was the same tank of E85?

 

I had to replace my O2 sensor already on my permanent installed LC-1 because I was daily driving on E85 and it fouled up my sensor . And just for your information, you can purchase a replacement at a local Autozone for $52 Bosch Part #17014.

 

Could be heaps of things.

How old is that tank of E85? (in weeks)

Did you pick the same gear when testing your AFR change?