Joined: Apr 2018

Posts: 6

Likes: 0

From: Utah

I have a 2003 evo 8 and today I went out to tune so I could clean up my fuel trims and make sure my fuel maps were good. Anyway while I was adjusting the injector scaling and the injector latency base, nothing was changing on my datalogs. I drove around for a good hour after I changed these values.

Second i went to do a pull on the on-ramp of the freeway and my AFR were completely wrong. In the high octane fuel map I’m supposed to be around 11.5 at WOT. But instead I started at 12.2 and it’s started to climb up to 12.9 in an instant so I let off around 5k rpm.

Anybody know what could could be wrong or affecting this?

Joined: Oct 2008

Posts: 809

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From: New Jersey

Joined: Apr 2018

Posts: 6

Likes: 0

From: Utah

I’m running 1000cc injectors on 91 currently. So I decreased my injector scaling from 713 to 696. And I increased my latency. I don’t remember those numbers but my goal was to richen it up. My duty cycle is hitting between 45-52%.

Im on evo 9 turbo, bigger fmic, hks 272 cams, 3” TBE. Stock maf but 3” intake. And the bosche 1000cc injectors. I’m hitting 25psi Of boost.

Joined: Oct 2008

Posts: 809

Likes: 26

From: New Jersey

Joined: Apr 2018

Posts: 6

Likes: 0

From: Utah

I am using a 310lph aem fuel pump and it’s about a year old. And my injectors are about 8 ish months old. And I don’t know if they are clean or not. I always run chevron in it. I’ll try getting some cleaner through them tho and see if that helps.

Joined: Aug 2005

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From: West Coast

Joined: Apr 2018

Posts: 6

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From: Utah

I guess it’s possible. How do you switch from main map to alt map?

Joined: Aug 2005

Posts: 5,690

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From: West Coast

Joined: Apr 2018

Posts: 6

Likes: 0

From: Utah

By any chance if the O2 sensors were ****ty, would they stop the car from going into closed loop? I don’t have any check engine lights but I have a hunch that they could cause an issue like this.

Joined: Oct 2008

Posts: 809

Likes: 26

From: New Jersey

Joined: Apr 2018

Posts: 6

Likes: 0

From: Utah

it drives just fine. No problems or anything. It richen out like it should under half throttle or so, it’s just at WOT. I looked at my data logs (yes I have a cable and evoscan) the Short term fuel trims are just reading -25. And don’t change at all and the LTFT(M) will read-25 until I press on the gas and it will change to +25. So I feel like those are my problems.