Stumble off idle with E85

[Wyosyclone]

Sy running E85 with appropriate fuel system mods. 80lb/hr injectors, BBK 58mm throttle body, fuel pressure set at 43psi.

Stumble off idle. IAC counts 29.

Helping with this remotely, but I'll ask for map values at idle. If that looks good, increase fuel pressure?

Any help is appreciated.

 

[EricM]

I would also want to see what the BLM is at idle, then off idle, to see if there is a large difference. For example if BLM at idle is 145, then it drops to 120 off idle, then that could cause a stumble.
Playing with fuel pressure can affect it also.

 

[Wyosyclone]

I would also want to see what the BLM is at idle, then off idle, to see if there is a large difference. For example if BLM at idle is 145, then it drops to 120 off idle, then that could cause a stumble.
Playing with fuel pressure can affect it also.

Thanks for that, Eric. I'm having him optimize idle kpa first, making sure he is using correct factors for reading E85 on a stoich gauge. He's going to make a log for me to look at. I'll post back with results.

 

[Wyosyclone]

In the ADX that has been used to date, AFR is listed as "Target Air/Fuel Ratio". I am assuming this is actual wideband-derived AFR?

 

[EricM]

Yes that's correct. As I recall, I originally put it into that spot in the datastream so it would show up in Datamaster.