Sync loss while cranking.
 

Hi,

I am having some issues where the engine stops turning while cranking.

I can see from the attached log that I am getting an sync error 31 quickly followed by a error 32 while cranking. Rpm jumps to around 2500 while cranking and ignition spikes to around 30. Seems like this is causing a backfire and it stops the engine from cranking.

I have attached a log from the startup, as well as the tune. I going getting a composite log tomorrow morning when the car has cooled down as I am not having issues on hot starts..

Battery voltage is dropping a lot just before the errors. Could this be due to a faulty starter? The battery is brand new!

BR,
Truls

https://www.miataturbo.net/megasquir...e-crank-80800/

Long story short, switch your rising/falling edge...

Will give it a try. Read that whole thread before posting, but read elsewhere that the MS2 should have Rising Edge.

Essential info: Stock 99 Miata, MS2E.

I don't think it is what the ecu "should have", but how the ecu reads the crank signal. Give it a shot and see, let us know!

It depends on the input circuit and decoder.

what exact MS model/variant do you have?

Reverant built MS2E. I haven't changed crank settings other than setting the offset.

you should ask him what's best for his unit. I'm assuming youll wanna keep it how it was setup to begin with.

Opto circuits. 90-97 = falling edge, 99-05 = rising edge.

Tried making some composite logs, seems like it stops logging sometimes while cranking. Anyway, I have made some progress. If I turn the key to the "on" position and let it sit for about 30-45 seconds before cranking, the chance of kickback is much lower.. Replacing the head this weekend, so I am going to clean the connectors at the same time, as well as checking grounds.

So back to this. Head replaced and removed A LOT of build up. Seemed a little better. Redid the cranking and pulse tables. All good now.