ECUflash Running Lean

[streetdsmpwr]

First of all, I am running ceddymods on my 99 ecu. I have my fuel maps set up at 11.2 to 10.8 AFR from 5500 to 7000, but at the track, my wideband was reading 12.0-11.8, which was causing a lot of knock. I had to set my AFR's to 10.0-9.8 to get it to stop knocking, but AFR's were still in the 11's. At idle and cruising my wideband is reading right on 14.7, so I don't think my injectors are scaled incorrectly. Anyone have any ideas?

 

[mike96]

where are your fuel trims sitting and what injector scaling are you using? Still could be scaled incorrectly or incorrect latencies.

 

[streetdsmpwr]

they are 750's scaled to 722. Last time I tried to log my fuel trims, they were off by a lot. When I finally got them to even up by changing the latencies, it was idling at about 13.5.

 

[mike96]

might want to try dropping your injector scaling a bit more, factory settings for the DSM are like 424 and the evo are like 513. you will have to readjust your latencies again but i think you will have a better time of tuning if you do. did you mess with the latencies on all the voltage settings or just at whatever voltage you were getting at idle? also were all three of your trims adding, subtracting, or both?

 

[streetdsmpwr]

I only looked at the low trim and I believe it was +10. This was a while back, I'm in school right now and my car is at home. When I go back I'm gonna check on all this stuff again. How do you tune latencies? The tune I am running now was a base tune from dsmchips.com that I modified. I know that he did change the latencies a bit, but I don't know what to look for when changing them. Also, I was messing with the injector scaling a while ago and I was able to richen it up at full throttle, but as I said my idle was at 13.5 after scaling them to about 670 or so.

 

[Tyeler18]

How To Tune an Evo - evolutionm.net

Second post should be what you need.

Also- Injector Scaling and Latency (SUPERMERGE) - evolutionm.net

 

[RLPerformance]

Never assume that the numbers in the fuel map are a direct relation to what the AFR's will truely be. You can't make the entire WOT cells 11.0:1 and see 11.0:1 in real time. Only timing maps are direct relation to what the computer outputs. You need to start rich on your whole map from basically 100 load and up and log AFRs. Then slowly lean them out until your in a safe AFR.

 

[streetdsmpwr]

Thanks for the input guys, I'll check it out as soon as finals are done .

 

[williillii]

Never assume that the numbers in the fuel map are a direct relation to what the AFR's will truely be. You can't make the entire WOT cells 11.0:1 and see 11.0:1 in real time. Only timing maps are direct relation to what the computer outputs. You need to start rich on your whole map from basically 100 load and up and log AFRs. Then slowly lean them out until your in a safe AFR.

If you have the MAF scaling and injector scaling spot on, theres no reason you cant make the fuel tables actually represent what your car is running.

I know some people put the car in full time open loop and then tune until the programmed values match the logged values. It makes things a little easier when making adjustments later.