Starting issue finally caught it in a data log

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This only happens maybe 1 or 2 percent of the time when cranking the engine, it happens on cold or hot start.

Looking at the first 10 seconds of the log you can see that it goes from run to warm, skipping cranking and ase.

Also iacv steps fall to 0 then start to recover but rpm falls below cranking rpm and then it goes into cranking mode and ase activates.

This has been happening for about 2 years but it is so random I haven't been able to catch it in a log until now.

I have attached a second log (functioning as it should) taken 2 days later with same conditions (cold start) except the ambient temperature is a little higher.

I am not seeing anything in the log that sticks out so I am at a loss as to what may be causing this issue.

When this happens I can cycle the key and it functions as it should.

David

EDIT: attached msq

[Matt Cramer]

Looks like it took a while to gain sync, and when it did, the engine was already turning faster than cranking RPM. That is what made it skip the cranking phase, and possibly the ASE as well.

[turbo conversion]

This is the first time I have been able to catch this issue in a data log and see what is actually happening.

I have noticed though that every time this happens the engine fires as soon as I engage the starter, there is only a .2 second delay.

I can always tell when this is going to happen because the engine fires as soon as I engage the starter.

I have skip pulse set to 5 and in the first log It seems to ignore that and fires the engine as soon as I engage the starter, in .2 seconds

If you look at the second log you will see the run indicator light up then in .39 seconds the crank indicator lights up.

Then in .547 seconds the engine fires and everything works as it is supposed to, this is what has me stumped.

What I can't understand is why it seems to ignore the skip pulse setting which seems to be causing the issue.

Is there anything you can think of that would cause it to ignore the skip pulse setting?

David

David

[Matt Cramer]

I see you're running an EDIS ignition. The EDIS module itself will spark regardless of the Skip Pulses setting. And the ECU will supply a priming pulse at key on. It seems like you're starting on the priming pulse and by the time the skip pulses have passed, the engine has already gone over the cranking RPM.

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Is there something in the settings I can change to solve this issue?

David

[Matt Cramer]

Zero priming pulse, or replace the EDIS with direct coil control.

[turbo conversion]

Thanks Matt, I will give it a try and report back.

David