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S-AFC II Help!

5503 Views 19 Replies 6 Participants Last post by  evolutionized
We installed an AFCII in my friend's evo the other day, and there are a couple issues going on with it.

First of all, the car stutters at low throttle (30%ish) sometimes, and kind of cuts out for a half second or so. Second, the RPM values on the AFC are wayyyyy off of the tach, which makes it hard to tune. At idle it says like 400rpms when the tach says 850or so, and the difference just grows. At 3000 rpms on the tach, the AFC says it is at like 1500. Any ideas? I set it up the same as I have set it up on all of my DSMs, so if it is different that could be it.

It has:

Intake, boost controller, boost gauge, and now the AFC. I set it up with Karman, Arrow up and to the right, 4cyl, etc.
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i had the same problem with my afc cause i did not have a working soddering gun. Did you use butt clips??? once i soddered the wires in worked great!!
It was soldered, but the guy who did the soldering for us somehow is positive that the airflow wire didn't have to be cut and he could just twist the airflow in and out wires together and solder them to the ecu harness. Thats wrong right?
well i cut mine....the wires on the ecu that have 2 afc wires going to them did he put them like and inch apart? thats another wayit could be messed up. Those wires really have to be installed apart. also if the rpm range is that off be carefulli have a buddy with a nissan 240 with the SR20det and he was having same problem and since the afc reads off of rpms he was messing up the air flow and fried a piston.
the ECU pinout is the same as the 2nd gen Eclipse...make sure all your wiring it correct. www.roadraceengineering.com has a good pinout to go by if you are unsure.
We're sure about the wiring, we just didnt cut and solder the airflow in wire and the airflow out wire seperatly. And we can't figure out why the RPM's read so much lower. At 7k, he reads like 2800rpm!
well redo the airflow wire and check all your wiring to make sure the soldering is done good. The problems you are having are common problems when a wire is not connected good.
What the AFC does is intercept and modify the airflow signal. You can NOT just twist the airflow in, and airflow out wires together and solder them to the stock ECU's airflow wire! I hope he didn't screw up your AFC permanenetly. If you re-do it the right way (cut airflow wire, and put one end of it on airflow in and the other on airflow out) and it still don't work then your friend owes you around $350 because Apexi will not warrenty an f'ed up instalation.

Keith
I understand whats happening now...of course it wont work right.

You cant just twist air flow in and air flow out together into the air flow wire.

You have to cut the ECU air flow wire use the end that doesn't connect to the ECU to go into the air flow in...use half that goes into the harness/ecu to connect to the ECU...don't let these two wires connect cause then the AFC will be messed up...

redo that and see what happens...
OK resoldered em and it works like a champ now...What are you guys running on your settings? I'm being cautious with his afc for now, as he doesn't have an EGT yet, but just leaned it out a couple of ticks so he can run 21psi.
was that the problem???? it runs good now???? i have my setting on the high side -11% almost across the board then at like 6200rpms -7%
Yeah that was it. With his, I put it at a safe -5% to -7% across the board seeing as it doesn't have an egt, we are just trying to take out the fuel cut.
glad to hear you got it working right:thumb:
OK one last question. We set up the knock detector as it says in the manual, and it reads 1-2 at idle. Anyone know what that means or if that gauge is even usable? I thought an otherwise stock car should have no more than 5 counts in a pull, and I am confused as to what it means when it says 1-2 at idle. Is it constantly detecting knock at idle?
including myself i have not heard of a single persons knock sensor working on the evo.
the Evo'srun rich, yes up top they do. From the 0- 10 psi range they are kind lean not that much but they are not the 10:1 a/f ratio that we are trying to lean out. It is more like 12:1 up to about 4500 rpms then it get choke rich after that. So -11% in the lower rpm band is not that good. I have seen some cars with +1 or +2 in the 3000-4000 rpm range. I will be putting on a Down pipe on my car this week and I will have a extra bung put on it for my FJO lamda sensor. I will get REAL readings and post Them up.
evolutionized said:
including myself i have not heard of a single persons knock sensor working on the evo.
So you tried to set it up via the instruction manual and got the same results?


*Everyone gaze in awe at my use of via.*
make sure you do that setting after getting the car really warm.....I say that it isnt very accurate, but its an idea.....to get true readings to really know whats going on and all that then you will need to get a wideband, which also will be my next mod, a wideband and a MBC.
93civEJ1 said:
make sure you do that setting after getting the car really warm.....I say that it isnt very accurate, but its an idea.....to get true readings to really know whats going on and all that then you will need to get a wideband, which also will be my next mod, a wideband and a MBC.
I say EBC....like Profec...they are so cheap, and well worth it in the end...I ended up upgrading from a MBC, cause it couldn't control high boost very well (19psi)...so I had to mod twice...just get a profec from the start and be happy from the start
i have the avc-r and i LOVE IT......one of the best mods i have done to the evo or my gsx.
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