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Discussion Starter #1 (Edited)
So is there another table besides Maff - EQ Ratio Gas - EQ Ratio Alcohol I should address for tuning PE?

Here's what I have:

EQ Ratio Gas: 1.280
EQ Ratio Alcohol: 1.250

When I'm running gasoline lambda in PE is pretty solid at .74-.76. When I run alcohol (E65 is highest my gas station ever has) lambda leans out as RPMs climb, from .75 - .83 and I let out of it before it leans out more.

I can fix this by increasing the EQ Ration of alcohol....like from 1.250 gradually getting larger as rpms climb (1.5). This keeps lambda in the mid 7s under WOT when i'm on E65.

My problem, if I run a low mixture of E, like E25, my PCM grabs that crazy raped EQ alcohol table and blends some of it into my EQ Gas table and things get to .68 lambda at 6,000 rpm under WOT.

Anybody have any ideas on how to figure this out?

Thanks

Jason




*EDIT

I'm not sure if this was my problem before DSX Aux pump or after. I believe before. It is possible this issue may be resolved. I'm flashing my PCM with flat EQ alcohol ratio and then fueling up with pure gas.....dialing in the maff table, then adding 100% flex fuel to double check lambda with flex.

I would have thought my injectors opening up more as fuel pressure dropped would have compensated, but perhaps not. That whole issue may have been because of dropping fuel pressure.

I'll log and report back in.
 
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Reactions: adam112

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FYI, the ECM blends between the two PE tables for gas and alcohol depending on the % of alcohol. It only goes in 25% increments from what I can tell (Someone correct me if I'm wrong). So @ 25% ethanol, it blends 25% of the alcohol PE table and 75% of the gas table to arrive at a number. 65% ethanol, it would use 50% alcohol table and 50% gas table. 77% ethanol would use 75% alcohol table and 25% gas table. There is a separate table for the spark that you can adjust what percent on the flex fuel spark advance table it uses, so don't think changing that will change how the PE tables blend.

Also just another side note, on ~E65 I run about .80-.82 lambda and the car seems to make the most power there on my setup. Your results may vary.
 
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Reactions: JAustin

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Discussion Starter #3
Filled up with E65 and after a couple maff adjustments I was ready to let third gear eat. Fueling held solid in the high 7s all the way to 6k rpm.

I can’t stress enough how important it is to upgrade your fuel pumps or add an dayz pump when running flex fuel. I’d tou have dropping fuel pressure I can guarantee your tune is crappy and your fueling is off. The only way for me to combat the drop in fuel pressure was to rape the Ethenol fuel table. If I ran straight gas I was fine, but any blend of E, and fueling got ritch as the the raped e table was blended.

I thought the ID1050s would just pulse longer to make up, I was wrong.

Moral of the story, if your fuel pressure drops at wot, fix it.
 
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