Hello all. My setup is on E85 on my Z. I have been trying to figure out this hot start issue I am having with this fuel. With regular pump it was fine, now its a bit tricky to get down with a different fuel. Here are my Crank enrichment and Crank timing tables.







Pretty much anything above 140 coolant degrees is a heartbreaker to get started and I have to repeatedly pump the gas to get it going. Cold starts are perfect and always start the car after about 3 cranks on its own without pressing the gas.


Any suggestions or advice would be much appreciated. Thanks for taking the time to read my question.

 

I’m skeptical of E85 (due to my own ignorance) but I have heard hot start issues are consistent around the E85 community ... I’d research what has worked on other platforms and recreate on your map.

 

This is true. It is a comnon issue with E85 on hot starts with all platforms of vehicles. But my question was if my crank tables were optimised enough to do the best I can with hot starting. It's a balance between ignition timing, the amount of air and amount of fuel. Just trying to see if anyone had any advice for me. This is the best I can get the car to behave atm. Thanks, i guess I'll keep on reading.

 

Drop that cranking enrichment that’s at 100 to about 50. And see how it does

 

or email me the tune and il make some cranking adjustments and send it back. 2bad240@gmail.com

 

I will email you shortly sir, thanks for your assistance.

 

Yea just try and cut your crank values down in the trouble areas and see if it helps.

That's what I did with mine but in regular pump. Tried everything until I found out I have to make -3 corrections on my lower table for it to crank like a normal car.

If not I'm either cranking it for 10 min and WOT to get it to crank over. Note my adjustments were needed to compensate for 2x stock injector size tho.

 

Feel free to ignore "cranking timing b" and "cranking timing c". UpRev has these defined and scaled incorrectly, they're actually cranking rotational energy compensation and cranking rotational energy compensation limit tables. And their values are much lower than it lists.

 

Thanks or your comment. I am a bit apprehensive atm to do any changes on my own now. So I am working with 2bad240 to fix the issue.

 

Wow, I had no idea about that. Thank you for telling me. I wont concern myself with those tables as much now.

 

With 2bad240's help with my crank maps, hot starts are a bit better now. I would crank on it forever once the engine was warm, but now it usually takes like 3-4 seconds with the gas pedal pressed repeatedly. I think this is as good as its gonna get for now. Thanks for everyone's assistance helping me figure this whole E85 tuning thing.

 

What did you guys change?

 

A little bit of everything in the crank enrichment table and Injecter priming tables were reduced to a lower value. I won't sat the exact value with respect to 2Bad240 (RZG Motorsports) but he did a pretty good job on the 1st edit.

We will continue to send logs back and forth in the future to further improve on it.

 

Yea that's the same thing I had to change with mine for larger injectors.

Probably the same principle but opposite.. My injectors needed less fuel cause of the increase in size.

You need more fuel due to e85 being less efficient than gasoline as far as unit per optimum delivery.