MicroSquirt.com read only forum (Jan.15,2018)

I am using version 3.346. I get spark at the proper time, but when tried to start engine, no fuel. I set the valu ADD Fuel to 2.0 and got the engine to run and idloe pretty well. Apector flow. pears from data log and engine perforance (leans out at 2000 rpm) the for some reason the uSquirt is not controlling the injector flow, pulswe width stays at 2.35 as I open the throttle. attached is msq that runs at idle and up to 2000 rpm.

THANKS
Elliott

For the configuration you have: 2 cylinder, 4-stroke, odd-fire, wasted spark, the skip teeth needs to be 9. This exact configuration is discussed under the microsquirt.info, Dual Spark page. With skip teeth = 18 as you had it, the rpm read 1/2 actual. With the change to 9 each ignition fired 2x per 720 deg (4 sparks total). The fuel was double this because it was set to simultaneous. If you set it to alternating you would get the same injections as sparks, but you would have to increase the fuel ve. In either case, I see the correct no. injections on both Inj1 and inj2 as rpm changes from 100 to 4000 rpm. The fuel pw doesn't change because your ve table has 24% everywhere up to about 6000 rpm.

Al, I got the engine to run, but when I set skip teeth to 9, cylinder 2 only fires once and then never again. With it at 18, seems ok although have no way to tell if rpm is correct, seems ok idles at about 650 rpm. Timing is exactly as we want it. I've had engine to 5000 rpm, then have problems leaning out. Playing with VE table.

I have some questions.

1) We want to go COP coils. The dyna coils we are using have 3 ohms resistance, the COP units we found have 1 ohm. Will using them be too much of a current draw on the microsquirt?

2) If we do use the COPs, do we still need the capacitor on each COP?

Thanks
Elliott

Al, one more question. If I hook an electronic tach to one of the could, and we are in wasted spark mode, will it show the RPM as twice what it really is? Is there a way around this.?

Elliott

If there is an error in rpm it is usually double or half, so unless you think you should be idling at 300 or 1300 rpm, you should be ok there.

I have never heard of a coil having too much load (low ohm injectors cause problems but not coils), but I will check into this for you. Plus I thought COP coils had a logic input and the coil drivers took care of all the load. If that is the case you shouldn't need any capacitors, they should be built in to the COP drivers.

When you go to COP are you changing from one dual wasted spark coil to two cop coils ? If so, you may need to change your configuration to get the ECU to fire both COPs, or are you also going to add a cam.

I need to know: no cyls, no coils, crank wheel teeth, missing teeth and cam sync or not.

All this info tells how to configure so you get correct rpm. If the rpm is correct, the tach out should also be.

Hi, Grippo.

Two- or three-wire COPs are dumb coils, just like the big ones used with a distributor. They're just smaller, and thread onto your sparkplug. They need a controller - VB921, BIP373, etc. They can be arranged as, well, 'COP' or as wasted spark.

Four- and five-wire COPs are your smart plugs, charging and firing themselves according to a logic signal.

EEstrine - what are those COPs off of? I've never heard of 1.0 ohm coils - 1.6 ohm is the lowest I've ever seen for TCI (Yamaha R6, '06+), while CDI COPs are usually much lower primary resistance.

I talked to Bruce about your COP coils and he said you really ought to use external drivers for them. Many people ignore this (it is very clear in the manual) and many people have all sorts of noise problems.

Al, We are working with a 500cc Turbo, 2cylinder 4 stroke, 80 degree apart cylinders. When I put skip teeth to 9 as you said in a previous response, no spark on cylinder 2. Also, we ran the bike on our chassis dyno. The Tach said 5000 rpm, but we calculated the rpm from the wheel speed measured on the dyno and at 50 mph, estimated it was at 9000 rpm. Also
one run, we had 17 pounds of boost at indicated rpm of 6000 and just dnt believe the rpm is correct. Attached is the current MSQ I'm using.

Elliott

Forgot to mention in above that we have a single crank wheel with vr sensor, and two coils.

Elliott

You have 2 coils and wasted spark. That means you have to fire each coil (cylinder) 2x per 720 deg, or 4 total sparks per 720 deg. An even fire engine would fire 2 sparks simultaneously, but with your odd-fire you should fire 4 differently timed sparks every 720 deg. The procedure is to set the engine as if it were even fire, so that means skip teeth has to be 9 so you get 4 separate sparks. Then you add in odd angle so that the sparks are not simultaneous. Skip teeth causes a spark to be fired every skip teeth.

You need to figure out why cylinder 2 fires once and then quits. Have you read
http://www.megamanual.com/seq/multichannel.htm, there is a procedure for setting up an engine very similar to your. Your trigger offset or delay teeth or odd angle may be off.