David Lewallen

Took a trip for a week without driving the miata - previously had no issues starting - and now the miata is really hard to start

It turns over just fine but 10-15 seconds of cranking. If I roll it and bump start it then the car catches immediately and continues to run.

I thought that possibly the crank sensor moved a bit but that doesnt seem to be the issue. When cranking I ca hear relays in the dash clicking and the fuel pump turning on and off.
At times I will get a really loud pop out of the exhaust - assuming its fuel pooling since FP is turning on and off.

I attempted to do a composite log but I dont understand how to read it. Anyone able to shed some light on all of this?

Keuzy

Try turning up your cranking pulsewidth. I had this issue, especially in weather below 40F. Mine would act like it would want to start initially, but continue cranking for about 10 seconds while it slowly but eventually stumbled to life.

What solved this for me is setting the cranking pulsewidth to 500% at freezing and below, tapering down to 100% at 130. I also run e85, but it seems to work fine when the tank has the occasional 93 in it. who woulda thought e85 could start so well in freezing temps!?