Loss of spark / revs

[beingblueeyes]

so did you ever get this sorted out? I have a zx9r also and am toying with the idea of puting efi on her (shes a 94 B1) but im a little fuzzy on using it to control ign timing, so im thinking of just using it for fuel, is there a way of getting the stock ign to work to trigger the MS unit just for a rpm sig for fuel? also what size wheel id you get from trigger wheels.com?

thanks

[nakedninja900]

beeingblueeyes
I thought I broke my starter clutch so I pulled the motor and upon stripping it I discovered that it was just the alternator chain which broke. So I have started assembling the motor again and I'm hoping to have her up and running this weekend.
I am still not able to rev out cleanly to 12000 (I'm only getting 9700) but I have a selection of resistors to try on the pick up wires which I'm confident will sort that and then it's just a case of getting the fuel pump fitted and go injection.you could run injection only and trigger off the coil if you want but it's pretty easy to fit the trigger wheeling you can use the original ignition pick up so I would recommend going for ign and fuel. If you do let me know and I can send you my tune so far.
I'll measure the trigger wheel again and let you know (I can't quite remember the size)

[nakedninja900]

Well I've had a chance to get some miles on the motor while the weather is good here but I still cant get the motor to rev over 9700. I have tried a load off resistors and also tried increasing the pick up air gap but no matter what I do I always end up losing revs instead of gaining them, I am running the dwell at 2.0ms at the moment and I'm thinking that maybe I should bring that down to allow the coils to charge, is there a general rule of thumb of a safe dwell time or am I barking up the wrong tree?
Cheers

[24c]

Hi nakedninja900,

It does sound like this isn't an over voltage thing with your VR, especially as you can't change the behaviour by increasing the gap or capping the voltage with a resistor.
Have you got a datalog that shows what is happening around 9700 rpm?
What sort of coils are you using?

Mike

[nakedninja900]

Mike
I don't have a log from the last dyno run but I do remember that I was not loosing sync but the motor sounded like it was hitting the limiter (which is set to start retard at 11500) I am running 4 individual stick coils (2 wire dumb) through a Bosch amplifier. If I reduce dwell time will the duration time need altering or will the Microsquirt figure that one out?
Thanks'

[24c]

[quote="nakedninja900"...iIf I reduce dwell time will the duration time need altering or will the Microsquirt figure that one out?...[/quote]
The MicroSquirt AFAIK is just a switch, if you reduce the dwell time, the coil will charge for a shorter period, it doesn't optimise the charge into the coil like some external ignitors. If your voltage drops the dwell time is increased as per your settings...so you need to look at the coil specs and their charging times. If your lucky there will be a graph displaying kV w.r.t amps & volts in the technical documents, with different charge durations.

Hope this helps
Mike

[nakedninja900]

Hi guys.
Been a while since I've been on here due to various factors, mainly 4 cracked pistons! Due to me completely cocking up my trigger offset. So I thought if I'm replacing pistons I may as well put in big ones so it's now a 950cc
during the build I have been doing a bit of reading andi have noticed that many people are running quite a high number in the "next pulse tolerance" bins. In my running bin I am running 20% but many are running up to 70% my understanding was that the lower number would provide more accurate timing or have I that backwards? Could this cause the engine not to rev out?
Thanks.

[nakedninja900]

Well I seem to be back at square one. I cant get the motor to fire I did a datalog while cranking and the dwell is going absolutely nuts, could someone please take a look and see what you think.
Thanks.

[Matt Cramer]

The dwell is going negative - something really odd is going on. Can you post the MSQ that goes with that log?

[24c]

Could this cause the engine not to rev out?

Hi again, sorry you're having hassle, and as Matt says your dwell is going negative... most odd. Also you're getting frustrated, because that throttle is virtually wide open during that datalog! Also PW is flat ?? and PW2 is a big spike... something doesn't seem right there either.

Corrupted msq?

When I was doing my engine, it was noise interfering with the sensor causing the rev stumble for me. Later it was the wrong ignition setting, and not enough fuel. I could get it to rev out if I blipped the throttle repeatedly. Just a 2¢ observation.

Have you checked if your getting sparks during cranking?
Mike