EDIS and Megasquirt
Posted: Wed Apr 27, 2005 7:34 am
So we got the EP Alfetta EDIS system running last night. It's a V2.2 board with MSn-E 024u2 code and MT 2.25b417. It's pretty new code so I was a little reluctant to use it over the 021i that I've been running. So far so good.
A few snags and hopefully this will help some people in the future.
1) Initially the MS wouldn't download tables after the flash. It looked like the addressing was off trying to use the MSn-E tables on a B&G codebase. The flash was always successful as was getting the parameters. Sending parameters cause corruption and gave me strange errors about power being too low for reliable flash.
It turns out it was the USB->serial cable I was using. This is a known problem. I switched to my straight serial cable from my car and it worked perfectly.
2) The wheel and VR sensor positioning was 180 out. Someone (not me) installed the missing tooth at TDC and the VR sensor at 90 degress ATDC. Specific angle being 90 for an EDIS-4, 60 for an EDIS-6. The missing tooth should be SPECIFIC ANGLE **AFTER** the VR. So when mounting a wheel, put the VR sensor wherever the bracket fits, then with the engine at TDC, position the wheel with the missing tooth 6 teeth (6 cylinder) or 9 teeth (4 cylinder) after the VR sensor.
3) VR sensor polarity was backwards. Because the VR sensor generates a square wave, the PIP signal will read correctly in MegaTune and show good RPM. However, the square wave will go negative when the VR polarity is backwards and cause random or intermittant spark. Someone (not me) wired the VR sensor polarity backwards and even put an o-scope on it and swore to me that it was a good square wave. And it was, except it was the opposite of what the EDIS module wanted to see.
I'm heading to Wisconsin tomorrow night to run this on the dyno to tune the spark table. Because this is a race car, we're seeing 80 KPA at idle (1275 rpm). The table is going to look really funny because the load points will probably start at 70KPA and speed points at 1200 RPM. I'll post the table for reference though I don't think it will be much use to anyone. It might be fun to look at for those running MT2.25 and the Extra code.
The owner/driver is running a National SCCA race this weekend. I'll be the crew for the weekend for the ignition system and whatever other work the car needs.
I'm so excited to have this thing running finally. It was a lot of time on the phone trying to debug this installation.
Lastly, if you haven't been to or signed on to the www.msefi.com forum yet, do so. I've often said the MS is a DIY system, emphasis on the Y. I was able to search the forums there and find answers to these issues without having to post and wait for an answer. It's so great to have a knowledge base like that right at my fingertips and a powerful search capabilty. As I said to the owner on the phone, it's EXTREMELY unlikely we're the first to ever have these problems. A quick search showed we weren't alone and a solution was a click away.
Take advantage of this great tool! Just as we are trying to build an Alfa specific knowledge base on this forum.
-Peter
A few snags and hopefully this will help some people in the future.
1) Initially the MS wouldn't download tables after the flash. It looked like the addressing was off trying to use the MSn-E tables on a B&G codebase. The flash was always successful as was getting the parameters. Sending parameters cause corruption and gave me strange errors about power being too low for reliable flash.
It turns out it was the USB->serial cable I was using. This is a known problem. I switched to my straight serial cable from my car and it worked perfectly.
2) The wheel and VR sensor positioning was 180 out. Someone (not me) installed the missing tooth at TDC and the VR sensor at 90 degress ATDC. Specific angle being 90 for an EDIS-4, 60 for an EDIS-6. The missing tooth should be SPECIFIC ANGLE **AFTER** the VR. So when mounting a wheel, put the VR sensor wherever the bracket fits, then with the engine at TDC, position the wheel with the missing tooth 6 teeth (6 cylinder) or 9 teeth (4 cylinder) after the VR sensor.
3) VR sensor polarity was backwards. Because the VR sensor generates a square wave, the PIP signal will read correctly in MegaTune and show good RPM. However, the square wave will go negative when the VR polarity is backwards and cause random or intermittant spark. Someone (not me) wired the VR sensor polarity backwards and even put an o-scope on it and swore to me that it was a good square wave. And it was, except it was the opposite of what the EDIS module wanted to see.
I'm heading to Wisconsin tomorrow night to run this on the dyno to tune the spark table. Because this is a race car, we're seeing 80 KPA at idle (1275 rpm). The table is going to look really funny because the load points will probably start at 70KPA and speed points at 1200 RPM. I'll post the table for reference though I don't think it will be much use to anyone. It might be fun to look at for those running MT2.25 and the Extra code.
The owner/driver is running a National SCCA race this weekend. I'll be the crew for the weekend for the ignition system and whatever other work the car needs.
I'm so excited to have this thing running finally. It was a lot of time on the phone trying to debug this installation.
Lastly, if you haven't been to or signed on to the www.msefi.com forum yet, do so. I've often said the MS is a DIY system, emphasis on the Y. I was able to search the forums there and find answers to these issues without having to post and wait for an answer. It's so great to have a knowledge base like that right at my fingertips and a powerful search capabilty. As I said to the owner on the phone, it's EXTREMELY unlikely we're the first to ever have these problems. A quick search showed we weren't alone and a solution was a click away.
Take advantage of this great tool! Just as we are trying to build an Alfa specific knowledge base on this forum.
-Peter