drewdq

iTrader: (9)

I filled up with E85 for the first time after my car has seen 40,000 miles of 93. I rescaled my 1000CC injectors to allow 30% more fuel, and with my 255 pump and 1000cc injectors I just could not get enough fuel at wot past about 5k rpm. I was pulling my fuel tables wayy down, but it had no effect. After about a day I started running leaner and leaner hitting afrs of 14+ under slight boost. I ran the tank down and switched back to 93, and reloaded my old maps - and I'm around 15-16 afr constantly now.

I've heard E85 can pickup a lot of crud in your gas tank, so I think I have a clogged fuel filter or injectors or something. What would be my best approach at this so I don't have to just go out and start replacing parts. I figure I have these variables:
-the fuel filter sock on the end of the pump (which some people call the fuel filter)
-the embedded fuel filter in the pump canister (where can I get one of these for cheap?)
-faulty fpr? (vac lines look good)
-clogged injectors

I'm currently running some fuel system cleaner through, but this is definitely not going to fix my fuel problems, although it appears to help. At this point I'm driving my car around with my injectors scaled back to allow for more fuel. But at around 5000 rpm my afrs still drop fast to 13 or so, at which point I let off.

Jim in Tucson

iTrader: (3)

Many people have converted their EVO's to E85 and have NOT experienced what you have. In fact, I can't think of even one that has. So, I have to doubt that the problem is actually E85 related.

So, assuming it is not E85 related, what could cause an EVO to run lean?

I'd say your list looks pretty complete. Add possible failing fuel pump. Does an EVO have a venting gas cap? I'm not really sure.

Anyway, it must be fuel related in some way, as I can't think of anything else that would induce enleanment except a fuel related issue.

I, too, am concerned about the fuel filter, even though I've not had any enleanment issues. I think this is where I'd start if I was you, although it ain't cheap. Here is a link to the fuel filter part number...#MR571545...and Bryan at GST recommends getting the "grommet" #MR431121 as well.

Bryan's fuel filter reference.

tephra

iTrader: (6)

when you say you rescaled your injectors - how did you do that?

what were your fuel trims like?

mplspilot

iTrader: (7)

Do you see 14.7 at idle still? And then 15-16 under boost? What was/is the injector scaling?

skiracer

iTrader: (1)

I don't think running fuel injector cleaner will help much since i think E85 would be stronger than the injector cleaner to remove debris...

drewdq

iTrader: (9)

On 93 I was still working on my tuning, and my scaling/latencies were:
Setting 1:
3.312
2.184
1.632
1.152
0.816
0.552
0.408
860 scaling
Cruise FT = -10.68
Idle FT = 6.37

Setting 2:
3.312
2.184
1.632
1.248
0.912
0.552
0.408
1008 scaling
Cruise FT -12.44
Idle FT = -6.5

Setting 3:
3.312
2.184
1.632
1.104
0.792
0.552
0.408
1044 scaling
Cruise FT = -12.5
Idle FT = -1.2

On E85 I was at:
3.312
2.184
1.632
1.248
0.912
0.552
0.408
696 scaling
Cruise FT = -8.7
Idle FT = 12.65

Now that I'm back to 93 after E85 (like 40 minutes of cruise and idle) I am at:
3.312
2.184
1.632
1.104
0.792
0.552
0.408
860 scaling
Cruise FT = -6.17
Idle FT = 12.65

At WOT I used to be very lean like I posted above, but it seems to be getting better after I used a e85/pump fuel system cleaner. Now I'm at like 12afr at like 5000 rpm and 13afr at like 6500 with 17psi before I let off. At idle when the car is cold I run 16afr.

I've been confused trying to scale my injectors, and pretty much have to have something weird going on. I should have been able to do e85 perfectly fine with my pump and injectors, but I just had no fuel flow. My wide band sensor is <1000 miles and was just calibrated. I've attached my fuel map, which has remained relatively the same.

mplspilot

iTrader: (7)

What's your warm idle? 14.7 or not? And why is the cold idle 16? On purpose or it's not tuned?

Your scaling for E85 was wrong. It needs to be 609 or under.

But if you keep going lean with rpm with your latest settings it may be a filter problem..

drewdq

iTrader: (9)

Once warm, yes it was 14.7ish and it's 16 cold idle because of my troubles tuning. I have scaled my injectors back as low as 500. It runs very rich, but still runs out of fuel at higher rpms under load.

tephra

iTrader: (6)

those fuel trims are horrible.

stop driving at WOT and get the trims as close to 0% as possible.

on your settings1 increase the LATENCY for 14volts a little bit. and then try again

drewdq

iTrader: (9)

Yea I haven't done much WOT at all lately, it's back to working on my fuel trims.

tephra, I followed the guide you showed me a few weeks ago:
I played with latencies/scalings for countless hours, allowing plenty of idle and cruising time. I think I was very close to zeroing the FTs with the settings below, but I ditched this and started over because it's soo different from what everyone else has with their pte1000's. It also ran pretty bad with a lot of lean hesitation.
3.312
2.184
1.632
1.348
1.012
0.552
0.408
scaling = 1170

I read that my maf could be scaled wrong or something, but could this have anything to do with why I have high load enleanment issues?

mplspilot

iTrader: (7)

Scaling tells ECU their size for use with fuel maps. You cant tell the ECU they flow 1170 where they are rated 1000... You need to scale them smaller (under 1000) or you will have lean issues. Around 860 should prolly work for gas judging by your experiments here...

tephra

iTrader: (6)

go back to your settings 1, and increase the latency for the 11v and 14v sections... just a little bit..

then try and idle for 10 mins and cruise for 15... then post up your new trims.

drewdq

iTrader: (9)

Here are my new settings and trims:
3.312
2.184
1.632
1.200
0.888
0.552
0.408
860 scaling
Cruise FT = -12.44
Idle FT = 0.49

Cruise FTs are still way off. Driving without boost my afrs are nice around 14.7, but as soon as I put load on (even a couple lbs) I start running rich sometimes in the 10-11's. Up top I still run a little lean tho, like 13.5 at worst.

Sorry for getting a bit off topic going back to pump gas here, but I would like to see how I can get my tune again with 93 to see if I do in fact have a delivery issue.

I attached my fuel map as well, as I'm open for pointers. I think I have some work to do. Thanks for the pointer tephra!

tephra

iTrader: (6)

The idle trim is still more positive than your cruise trim.

So try increasing the 11v and 14v just one more little bit.

Once we get the Cruise+Idle fixed then you can tune your fuel map.

mplspilot

iTrader: (7)

The method of bringing idle trims close to cruise trims with latencies and then adjusting scaling to move them together to 0 as described earlier is a good idea that makes sense. In theory. In practice it does not work for everyone because a lot of people run aftermarket intakes that mess up MAF readings at slow airflow at idle. In those cases it's been my experience that the best way to adjust idle trim is to add fuel with MAF scaling table at low airflow..
And once you've decided on injector scaling, tune latencies for cruise trim.. I would think ~ .750 is whereabouts your 14v needs to be...looking at your results here...
just my .02