Issue Switching Between E85 And 98

[nj1]

Hi all,

My car normally runs united e85, but fuel was low in the car and I put in 98, but the car appears to misfire/cut at 5000rpm in second gear with medium throttle.

The car is R32 RB20det, has eflex sensor and it is tuned to run on both e85 & 98.

The car had not been driven for 3 weeks either.

Any ideas on what the issue could be?

[Ben C34]

Was the tune for 98 ever any good?

[Piggaz]

What does the sensor say? E0?

[nj1]

Yeah tune was fine, but as soon I got it put on e85 6 months ago this is been the first time I have used 98

Do you think I need to get the 98 tune checked?

[nj1]

What does the sensor say? E0?

I don't have a display/read out of ethanol %

[Ben C34]

Well the tune is scaled non linearly between 98 and e85 timing wise. There's a chance that the tune is off in between, as you probably still have some ethanol in there now. I would imagine straight 98 would still be the same as it was before, they wouldn't have had to change it.

[Piggaz]

Drain tank again and put more 98 in it. You'll be surprised at how much E85 is still floating around when you thought it was "close to empty". Better yet, take the return off the regulator and let some flush through the system.

[nj1]

Drain tank again and put more 98 in it. You'll be surprised at how much E85 is still floating around when you thought it was "close to empty". Better yet, take the return off the regulator and let some flush through the system.

I did the opposite and filled it right up with e85, 0.70 tank e85 & 0.3 tank 98, plugged the lappy into the ecu and got 54% ethanol. It has still has the miss, I guessing the 54% is too far away from the 85% it's been tuned to on ethanol and tune isn't adjusting correctly?

[Ben C34]

I did the opposite and filled it right up with e85, 0.70 tank e85 & 0.3 tank 98, plugged the lappy into the ecu and got 54% ethanol. It has still has the miss, I guessing the 54% is too far away from the 85% it's been tuned to on ethanol and tune isn't adjusting correctly?

If you paid for a flex fuel tune you haven't got one by the looks of things. Have a chat to your tuner.

[Piggaz]

You're 31 % away. Lol

Do it again.

Depends what you have paid for

A "flex tune" or E85 and a 98 tune. Having the fuel willy nilly in the middle of no where, of course it's not going to run right.