microsquirt for fuel only

[phazer]

I'm having trouble figuring out how to control timing on our 2007 phazer cop engine. We were thinking of just using microsquirt for fuel control only. How would I set up microsquirt to do this? We already have all the sensors working except for the crank sensor. Would I still have to use a 36-1 toothed wheel? the stock engine comes with 18 small nubs on a magnetic rotating housing shown below. The reason I am delaying timing control is because it has been more and an effort to get a trigger wheel on the crank due to packaging. If we can't use the stock wheel just for fuel, then we are back to the same problem as with before

[Bernard Fife]

phazer,

You don't have to use a 36-1 wheel for fuel only. In fact, you can trigger off the coil negative terminals if you like (this is probably the simplest set-up). You will need some diodes to get signals from each of the coils (without letting them 'cross-talk').

See the EDIS page for how to set up the diodes: http://www.megamanual.com/ms2/EDIS.htm (you will need one 1N4004 for each coil negative terminal).

The stock wheel might work. You need one signal event per ignition event. So for a four-cylinder/four-stroke you would want 2 events per revolution.

However, since you are doing fuel only, you don't have to worry about the ignition timing, etc, and can usually use any reasonable number of teeth (the rpm will be wrong, but you might be able to change the #cylinders, etc. to get it correct - you might even be able to use the missing tooth configuration (with 0 for the number of missing teeth)).

Sop the short answer is yes, you can do fuel only (I did it on my Honda for several months) - there's a few ways to do it. Let us know more about you set-up (#cylinders, wheel teeth, etc., and we can comment more thoroughly).

lance.

[phazer]

Sory for the lack of info. Here is what we are using for an engine
its a 500cc 4 stroke twin the cylinders fire 180deg apart. It uses coil on plug ignition with a coil per cylinder and fuel injector per cylinder. We have a gm flex fuel sensor an are using it to create a flexfuel snowmobile for a compitition in early march. We have been going in circles for the past couples months. What we originally wanted to do was run it completely on microsquirt, but we have hit many bumps. Why I wanted to try fuel only is because of sensor issues. On one side of the engine is a gear reduction box that transfers power to the primary clutch, and the other side is the AC magneto shown in the picture above. There is no good place to bolt on a 36-1 trigger wheel. We had hoped to use that with a cam sensor to do cop ignition. There is no room on the camshafts to attach a toothed wheel, but the stock ecu uses a solid wheel attached inbetween cylinders on the exhaust cam with a pie slice cut out. This coincides with tdc of cylinder one.

I was trying to simplify the process because since the sled is designed to run on 91oct I was hoping stock spark timing leaving it alone would be fine. We just started looking into using a fored edis for spark timing but are not very knowledgable in that area. I'lll trying to post more later

Any info/encouragement/idea is greatly welcomed!

Thanks!

[ohgood]

Hi there phazer, others. I'm also getting started with a 500cc project. Mine's a gs500 that I hope to have fuel injected simply to replace the carburetors. Right -now- fueling is the only focus. At some point I may look into ignition also.

I'd like to follow your success here, and stay in touch, if you like. Would you mind pointing me to whatever resources you've used for selecting your throttle bodies, injectors, etc ?

Thanks !