Thread: Verify HPT tune?

Hi Folks,

I just tuned my car for e85 using the method in the sticky (i think) and filled it up with 14.5 gallons of Ethanol. Unfortunately my Gas gauge lied telling me the car was empty.


Id love to have someone check the tune I did and see if i actually did what i was supposed to. (changing the injector gain by cylinder to 1.3)
I am a bit skeptical because I flashed the car, realized the pump i was at was Out of order, and had to start the car and move to another pump. The car had not indication of being different.
Another concern is that i adjusted the injectors to 1.25 to adjust for not being on pure ethanol. The LTFT was really high, like above 10 on my drive home.

You can add a copy of your tune to your post so that others can open it and see what it looks like to verify it for you.

here is a link to the file buick tuned maybe.hpt - Google Drive

Originally Posted by SgtMarshal

to tune for E85 you only change the cylinder gain to 1.3. do you have facebook?

Unfortunately not. I deleted it a while ago, and havent looked back.

Originally Posted by GTPpower

Give it some time. Ltft's should get closer to 0.

I put about 100 miles on the car and fuel trims, especially under boost are reading in the positive. Under boost the car was showing 11%. I used HPT to clear the LTFT and it very quickly learned back into the positive.

If i remember correctly positive fuel trim means the car is adding fuel right? that would mean its running lean. Could my fuel filter be clogged? i was running an e30-40 blend for about 2 tanks prior to the almost full e85 tank.


I am just a bit worried about leaning the car out. I changed the injectors to 1.33 and it seemed to calm it down quite a bit. But that is way more than what my ethanol content should dictate.

i added a quick log i took if anyone wants to take a look Update your browser to use Google Drive - Google Drive Help

pos trims are lean. but wot your also locked in to pe mode, the trims just locked in what ever they were just before you entered pe.

cant watch the scan now, its time to crash lol but you got the wb imported to the scanner as well?

I'm all for whacking a table with fuel just to see if it does what I want.

So say you are still running positive trims of +10%. In this case I'd smack the whole MAF curve with 3% worth of fuel, reset the trims and see how much closer the trims get to 0%. My hunch is that you'll get down to around +4 to +6% give or take with the fuel added.

Once I know it's working, in most cases I use the wideband to find tune everything from there.

Do i need a wideband to run corn? My plan right now is to replace the fuel filter today, (the tank will almost be empty) fill up with e85 again, and then start dialing in the injector settings starting at 30. Then ill dial in the LTFT.

set your injectors and leave them alone. tune the maf, and it dont matter if your stock or modded, if your tuning wot, you need a wb.