hrm, thanks for the tip, gonna go over a friends house and pull the plugs to check the gap, gonna log the cruise trims on the drive over, and ill check the idle while im over there and report back.

 

Can you elaborate on this point MrFred?

Was it that your initial scal+late were not correct? And that E85 just highlighted this more?

 

When I switched to E85, besides the 30% reduction in injector scaling, I ended up having to tweak both latency and injector scaling to get the idle and cruise trims under tight control. The way I look at it is that my pump gas latencies were off a bit, but I was unknowningly compensating with injector scaling.

 

Hold on - If the Low/Med trims are both negative OR both positive then you fiddle with scaling.

If they are un-equal then you play with latencies.

So what were your trims before and after?

 

mrfred: Good tip. I had a second set of scalings/latencies that a local tuner used on a friends car that I have been meaning to test. I plugged those values in she started right up. I was able to drive over to my friends house, but was not able to boost more than 8-10psi before the car felt fidgetty.

After changing the spark gaps from .022 (stock) to .019, i took it for a test ride and it boosted more, but got fidgetty around 15psi.

On the drive home, I went to merge on the freeway, and as soon as boost kicked in, I could hear the stock DV open and dump into the intake

Within a minute or 2, the CEL came on. P0134, front o2 sensor malfunction. Im hoping maybe when we removed the plugs, we accidentally disconected the front o2, although i doubt it, ill check that in the morning.

With my wbo2 not functioning, i wasnt feeling confident with pushing it, so i cruised the rest of the way home. As i came up to 2 blocks from my house, i decided to see if the car would stutter again...and it ddint, I did a 3k-5.5k pull in 2nd, and it ran like it normally did.

...I'm 'cornfused'

Thanks to everyone for the help so far, Ill post up tomorrow if i find anything, and tomorrow night i should be able to log my trims and whatnot. At least it is running like normal now...less the CEL!

 

Log those trims. I'll bet the front O2 malfunction is because the injector scaling and latency values need further adjustment.

tephra, before I further tweaked the latency values, one of the trims was a bit positive and other was a bit negative. When I switched to E85, one of the trims went further away from 0 than I wanted.

 

quick question, when you reflash the car, does it clear the CEL? I didnt think so, but i checked the sensor, looked fine, replugged it in, reflashed the car with some minor changes and noticed the CEL was gone.

 

If you have an Evo IX, the CEL codes are cleared with every reflash. If you have an VIII, they are not.

If you end up needing/wanting some professional help, I've done quite a few E85 alt-map tunes on our Mustang dyno in Torrance.

 

Along with the other several E85 threads on here, this one also provides some nice information to know before I personally make the swap. I have a station less than five miles from my house and E85 is now $2.99/gallon. I'd be interested in checking out some of those ROMS if you could send them to evo_boy_1977@yahoo.com. Thanks.

 

Hmm I just picked up on this... one trim negative and one trim positive.

I have the same thing going on one is -1 or -2 the other is + 4 or 5

So i need to redo latencies then. Is there a specific thread on tuning the latency it self ?? In order to move the positve to zero do I increase the latency ? Im thinking yes to that

Milburn

 

Havent had a chance to do the normal 15-20 min cruise yet, but based on my drive to work, my trims were +3 low, +2 mid and my o2 feedback trim was 20-25. I checked when I got home, and the trims were +6.5 mid / 3.8 low and the STFT was 5.

If memory serves me correctly, I need to increase the scaling value, correct?

I also learned today that the car does not run well until its warmed up for a few minutes.

Im gonna test the trims tonight, and I'll post up what my trims look like afterwards.

 

02 feedback at 20-25 is basically maxed out trying to add fuel. You are too lean.

What is your latency at 14v?

If it doesn't run well in Open Loop (Which it is when warming up) then you need to put your fuel map back to normal 14.7 or so in those areas. I believe you had it much leaner for your E85 map?

 

i had it at 13.4 or so as a temporary measure to limp it home. those cells are back to 14.7 now.

my latency at 14v is 0.696

 

And your scaling is in the upper 5XX?

I would try adding more latency at 14v and a little less scaling. try around 570 or so and 0.720 at 14v

How much regular gas did you have in the car when you filled up with E85?

The car should run ok with +6.5mid/+3.8low and STFT at 5

I'm starting to wonder if the E85 you got was bad.

 

my tank was almost bone dry. I put 13.1 gallons into the tank.

That would suck if the gas was bad...i have another ~8 gallons out in the garage.

my current scaling is 573. If I increase the scaling at 14, should i increase the scaling at 11 as well?