loppad

Before anything I have to say that AEM EMS is one of the best computers I’ve ever seen. So flexible and customizable that you have to learn in deep advanced fuel injection to understand it (or try to).

This is my car:
2006 Evolution MR 9
AEM EMS 30-1320
AEM wideband gauge type
AEM fuel rail
Walbro 255 fuel pump
Delphi 880cc @ 43.5 (not listed in AEMPro software)
Stock Turbo
MAF based but want to convert to MAP soon.

First I had to find out which injector’s configuration might work for these unlisted Delphi injectors. My best option was RC engineering 900cc for the Injector’s Battery Offset. Now the engine starts and idles. I don’t know why AEM has the option “Crank Inject All” off; many cars won’t start because of that.

According to the manual I had to change injectors. Evo’s fuel pressure is about 52lbs so these 880cc injectors must be entered as 960cc or so. I thing to observe: do these change injectors in the “View raw”, this is mentioned in the manual but I didn’t notice it the first time I read it; otherwise changes won’t take effect. The rest of my AEM EMS configuration (acceleration, deceleration, spark, boost, variable cam, etc) has stock values.

I configured Automap as the manual says. Automap’s Fuel Target map was taken from the O2 FB Target Map; values seem reasonable to begin Fuel map tuning (14.7 going up to 11s). I took the car for a ride (not integral traction dyno in this town). Idle and part throttle got much better, acceleration is great but I saw Automap adding fuel about 10 to 20%.

But when I did WOT (about 200kpa) automap added a lot of gas. So much that cells start to get 255 (the upper limit) and then injectors went static (100% duty cycle) and of course the engine suddenly leaned badly (up to 16 AFR shown the AEM Gauge).

I changed my approach for fueling: instead of adding fuel I was going to subtract it. So left the original Fuel Map (intended for 550cc stock evos injectors) and then trim the cells. Automaping idle and part throttle did what I thought: excess fuel was removed.

But at 2/3 throttle (not WOT) by 210kpa, automap added fuel (say from 170 jumped up to 210). In WOT things gets worse: up to 255 and then injectors get static and lean again.

I saw a post where another evo 9 owner (map based) had its Boost Target Comp table in 0% all of it, arguing that is better to adjust the Fuel table properly than trying to fix using this table.

Is this Boost Target Comp table doing this to my fuel map tuning?

Am I using wrong the automap function?

Something I’m missing for the proper Fuel map tuning procedure?


Thanks!

loppad

Fried_rice

Adjust the fuel tables manually? I've never tuned with AEM, but I would suspect the automap feature is used to get the car a rough estimate so it can be driven to the tuner. You should either have someone drive your car or hold the laptop in your lap while you drive and tune, making adjustments on the fly. Log your WOT pulls and add/subtract fuel where you need to. Make sure you know what you're doing, before doing more WOT pulls...

mandy1

iTrader: (1)

i never use the autotune,if i do,i lost interest in this hobby,yea,its a hobby that pay me, first check fuel press at wot where you start to lean.

loppad

Yeap, Fried_rice manually because the original fuel map, even properly scaled using the new 880cc injectors, becomes very lean. Seems that my approach is working: use the original fuel map (very rich because is for 560cc) and then trim the fuel map so I'm safe at WOT.

Yes, someone else is driving the car as I check how automap trims the cells and for much. The only matter is that automap gets confused if you're accelerating or desaccelerating: it trims too much the cells while in those transition states that makes fuel map exaggerated (hills and valleys), not normal for a fuel map or engine behavior as well. Seems that automap has to be used only in very staying fuel states, that’s why a dyno is essential (in this case an integral traction one).

Well, I've been reading about automap and for many that feature makes the difference among other race computers: makes AFR changes on the fly, you don’t have to log first and later make changes in the cells. I think just isn't very well documented how to use it properly.

loppad

loppad

Hey mandy1, then how do you correct AFRs? You use O2 wideband anyway, do you?

Yeah, I kept thinking this weekend that maybe the fuel pump (even that I’m using a Wallbro 255) isn't doing his job. How you recommend me to check fuel pressure in a safe way (not in WOT pulls I mean)?

Thanks!
loppad

Fried_rice

Firstly, I could be wrong but I think bigger injectors would be adding more fuel causing you to run rich NOT lean. You say it's going 100% duty cycle and running extremely lean. You may have some fueling issue you need to work out.

I wouldn't even use the automap feature to tell you the truth. Here's how I tune. Have some one drive you around normally. Be on the laptop I'm sure you have a wideband and are monitoring it while you tune. There should be an option to turn "follow me" or something on something similar. This means the curser box that adjust fuel will go to what ever RPM/lbs boost you're at. Tune to 14.7 while cruising and when you deccel tune all the way lean or to where your injectors shut off. Your map should have no valleys and mountains.

When doing WOT runs add a-lot of fuel in the areas where the car will be seeing boost Ie.. 4000+ RPM 10lbs+ of boost( I don't know where the stock turbo spools but wherever it does make sure it has fuel). You can always take out fuel if you're running rich but you will blow the motor running lean.

While doing WOT runs make sure to log them. Have your friend floor it and if it gets over 12 AFR tell him to STOP Immediately, also stop the log. I tune to 11.5 which some may consider a little rich but I'm pretty conservative. Go back to your log and see the RPM/Boost range and what AFR it's running go back to the fuel table and add/decrease fuel where needed. Repeat the steps until it's all tuned.

Fried_rice

Only way to check fuel pressure is with a fuel pressure gauge. The fuel pressure should increase with the boost 1:1. So if you run 50lbs at idle and are boosting 20 lbs it should go up to 70lbs fuel pressure.

Do you have a fuel pressure regulator? If so it usually has a gauge.

EDIT: If not, I suggest you go to one of the performance shops or Autozone, they have cheap FP gauges. They're a must have IMO...

loppad

Yes it was lean because the "Change injectors/pressure" feature in the AEMpro software made the map so. I changed my approach and used the original map, very rich indeed because it was designed for 560cc injectors but “Better rich than sorry”. I’ve been trimming since then.


Actually I decided to pace myself so yesterday I was tunning cruise at 14.7, just as you mention before going into boost. Seems that AEM tuning takes time and patience: you have to teach it how to walk before make it run. I was having a deccel issue (car stalled as while approached to a stop) and automap did the job leaning cells in 21kpa range from 5000rpm all the way down to 800rpm. That issue is gone.



Stock Evo 9’s turbos spool around 3500-3700 at 21psi according to this post:

https://www.evolutionm.net/forums/sh...d.php?t=302895

Which is a great essay by the way, I whish there was a post like that for AEM.
Evo9 owner nj1266 mentions something similar as you:

“Setting your AFR depends to a large extent on the boost and timing that your car is running. When running the boost and timing mentioned in this essay, I generally set the AFR at 12.5-12 during spool up, 11.7-11.5 during peak boost, and then slowly taper the AFR until it hits 11-10.9:1 by redline/cutoff.”

I’m using his spark tables and my AFR targets are AEM’s originals which are exactly like those that nj1266 mentions.

Yeah, I agree 12s AFR is too lean for a turbo/supercharged engine.

loppad

Mmm just as I though. There’s an issue here: car has an AEM fuel rail and for some reason it doesn’t has a stock/normal fuel valve to attach the pressure gauge. Let me see where else I can take the reading.

By the way, thanks for all your help . This forum is great, better than AEM’s which by the way nobody has answered my post so far.

loppad

Fried_rice

If you have an aftermarket fuel pressure regulator it should have an extra bung with either a gauge or a plug where the gauge goes. Do you have a vaccum hose hooked into you FPR? Is your FPR a rising rate? If it's a rising rate FPR and doesn't have a vaccum/boost line hooked into it then at WOT it will be the same as idle causing a lean condition.

If you still have trouble and are anywhere near Bellaire(610/beechnut) I'd be willing to take a look at it.
-Logan