AEM EMS-4 Idle help
 

With help from Savington I got the 12+1 trigger wheel working. So it runs, but pretty roughly. First start was not getting enough fuel so I juiced up the fuel, which helped immensely. I do have a wideband on it, but not tied into the ecu yet. It was reading 13ish at 4000 rpm and generally in an acceptable range when giving a little gas. It instantly stalls when I let off throttle. Not exactly sure what to start toying with to try and get it to idle. I also noted that the tach was reading about double what the ecu was telling me. Pretty sure tach is correct. I am attaching my cal. file and would certainly appreciate an expert review and any guidance as to potential next steps in dialing it in.

Have you read the manual on the tach "divider"?

Adjust the idle base duty. If it doesn't seem to make a difference, your idle valve may not be working.

No, but it looks like I will be. Thanks

I will try to figure this out tomorrow. I ended up making a few other changes this afternoon and unfortunately it went from bad to worse. I hooked up the wideband input and modified some of the sensors with the setup wizards and the last time it was running the WB was pegging 10 and blowing lots of blue smoke. Obviously I changed something I shouldn't have. Lesson learned; change one thing at a time.

So after sending up smoke signals I reinstalled the map that was good and can't get it to start. Wondering if maybe I fouled the plugs?

You're flailing.

When you say idle valve are you referring to the IAC?

Idle Air Control valve, yes.

The good thing about flailing is that hopefully it means I have bottomed out and that there is no where to go but forward. I replaced the plugs today and got the old map to work. I plan to move on to fine tuning the idle this week. I searched the AEM manual and was not able to find any instructions regarding the tach "divide".

Setup -> Advanced -> Tacho -> Options -> Tacho

Try doubling the number in there.

Don't laugh too hard, but I had no air source for the IAC. My installer was using a different IAC previously and plugged the stock one up, and I did not think about the fact that with the AEM we were switching back to it. I reinstalled the bypass line today, and idle works great. Plan to go through the idle tuning process this week.

Thanks again.

There you go.

Idle tuning is pretty straightforward. Start the car when cold, and compare the target idle speed to the actual idle speed. If they're close, look at the "learned idle DC%" value to the left. If it's way negative, add duty cycle - if it's way positive, decrease duty cycle. Ideally, you want the "learned" value to be as close to zero as possible at all times.

Thought I was making progress, but haven't been able to get the IAC to respond so that I can move on to idle tuning. I used the settings and instructions in the manual, but adding duty% either up or down does not alter the rpm's. Also did the invert idle option (wasn't sure if the idle invert FB needed to change?

Still having the same issue with the tach also. I got to the tach table, but I can only either enter 1 or 0. Not sure if I have to change any of the table settings associated with the tach.

We have idle (now on all four cylinders). EB Turbo helped me figure out I had the coils set up for batch fire rather than wasted spark. It sure runs alot better with all 4 cylinders. I am so close to getting this thing back on the road. YEE HAW!