Recently got my car tuned on 93oct and E85. I've noticed an odd Idle issue when using the 93 map. Watch the video below and shoot me your thoughts. I'll ask my tuner tomorrow but I wanted to get your thoughts. It was also doing this while cruising on the interstate at 70-80mph. The problem is intermittent as you see it level out at the end.


Mods:
TBE,ETS IC, AGP LICP, TurboXS UICP, Greddy RS BOV, HKS 280 cams(old style), K&N intake, FIC 950CC, Walbro 255lph.

What I know:
There are no boost leaks, I've already checked for that.

 

So it idles fine on E85? maybe bad gas? my car idled like that once when i had a small vacume leak and dirty IAC valve. hoepfully your tuner can figure it out.

 

Update:

So the issue has progressed and now the car is idling pig rich (12-11.1). I doubled checked for leaks and found none. Something is going on because at some points it tries to pull %25 fuel. Below are my included logs, one from warm up and the other from warm up and some cruise. It almost seems like the o2 sensor has failed except it happens in both open and closed loop. Any thoughts would be appreciated!

 

Can you post a copy of your rom?
It could be the injectors calibrations, 93 should have different injector scaling than E85.

 

That's weird that it's intermittent and not just rough the whole time. Did you empty all the 85? Maybe try swapping back to the 85 map and then back to the 93 map. What did the tuner say?

 

Interested to see what the problem is, I have a similar problem only on 93 as well, does not do it with e85 for me either. I'm guessing something with tune.

 

Update:
Well I've driven around for about 3hrs now and the problem has gotten better(still there but better) I'm starting to think there may have been some residual E85 left in the tank and is causing the bouncing back and forth. Does this sound right? The injectors are scaled differently per each map. Ben says it could be a MAF scaling issue due to a vacuum hose that may have or may not have fallen off during the tuning. I may just drive it back up there and let them hash out the problem. lol I'll build them and let the professionals tune themlol

 

are you running Tephra V7? if so which rom id?

 

How much fuel is left in the tank? Drive around until your fuel light comes on and then drain your tank from the plug and refill with 93. If this doesn't work you might of been tuned on some 93/E85 mix because you didn't drain it like this when you got tuned.

 

3/4 of a tank. The car was drained of 93 before it was tuned on E85. I'm starting to think it was just a mixture of the two gases, if so I'm going to have to figure out a better way to switch maps, probably empty the tank completely before switching.

 

Update:
CEL came on today "Heated Front Oxygen Sensor No Activity" This may have been the culprit all along.

 

Only one way to find out. Replace it and see if the issue is fixed. Could've been a coincidence but hopefully that was the problem.

 

Did you figure out ur issue? was it the O2 sensor?