Megasquirt Project, .....IT RUNS ! Options

[Michelj13]

Hi,

Although I have been a member for a while (since I purchased my 914), I have not posted much. I still love my 914 and it's is interesting how this car drives like an absolute go-cart.

Anyway, my engine is a carbed 2270 that I built up with the help of many including Jake, and I am now embarking on a Megasquirt project. As many know, megasquirt is relatively inexpensive for a programmable FI system. I find, however, that there is too much information out there that it is nothing short of confusing. I want to share my progress so that at the end of the day, some may learn and may become less intimidated. Hopefully I will be successful....we'll see.

I have so many questions that I will post, along with some things that I have already learned. ANY and ALL comments appreciated.

I made a youtube video of my progress up to date. Enjoy!

http://www.youtube.com/watch?v=RoJfMZ9YgQc

Michel (IMG:style_emoticons/default/smile.gif)

[Michelj13]

I have a wideband O2 sensor from AEM. At idle, AFR is about 12.5, MAP is 85.

The timing can be adjusted with both trigger offset and advanced in TS ignition advance table. I have been around and around with these. It can get a little confusing especially looking through a mirror at fan markings. Bottom line is, at the fan, I need 5 degrees ATDC to achieve idle when looking at the fan markings.

I know it does not make sense. I will be a few days before I can play some more.

[JamesM]

You need to be absolutely sure that the timing you are setting in megasquirt matches the timming you are actually seeing with your timing light. When you get the time to work on it again here is what I would do.

1.Make sure your fan has all the timming marks so you can see them with a timming light. Just to eliminate variables here you dont want to use an adjustable advance timming light so we will need all the marks.

http://www.pelicanparts.com/techarticles/9.../914_timing.pdf

2. Under the ignition settings there should be an option for "Fixed Advanced", enable this (rather then use table) and set the fixed advance to 7.5 deg. If your car wont start with this setting then you can start it using the table and switched to fixed advanced with it running.

3. Every ignition event *should* occur now at 7.5 deg advance regardless of engine RPM or load. Confirm this with the timming light, you should see the 7.5 deg mark, if not then something is set incorrectly with your ignition setup and this needs to be resolved before anything else can be done. Most likely this will be the trigger angle that needs to be adjusted. Adjust until you are actually seeing the engine fire at the fixed 7.5. This confirms that the advance that MS is sending is the advance you are actually getting. Once this is has been confirmed change the fixed advance setting back to use table.

4. As an extra check that things are advancing properly I will set all bins on the ignition table 3000RPM and above to 27deg advance then check the timming while holding the engine RPMs over 3000, you should see the 27deg mark with the timming light.

This is all just another sanity check but should confirm that what you are seeing on the timming table in MS is what you are actually getting. VERY important to do before trying to tune, otherwise you are just chasing your tail.