hi_im_sean

iTrader: (3)

No

Arca_ex

iTrader: (2)

x2

Go look at the problem I was having with that in my thread. It ended up being a loose ground that intermittently turned the fuel pump off for a split second...

aidandj

iTrader: (5)

cool thanks.

codrus

I doubt you'll be able to see it with an NA cam sensor, there aren't enough teeth and there is a lot of error in the signal timing because of the cam belt.

There's probably power to be had by putting a crank angle sensor on there and gaining spark accuracy.

--Ian

aidandj

iTrader: (5)

I've looked into it. Almost got a spm damper with a 36-2 wheel. But there is also more power to be found by installing one of the VVT motors in my garage.

aidandj

iTrader: (5)

Finally got a good log. Captured 4 or 5 events. I'll post when I get home. I believe it's dying coils.

codrus

Indeed.

At least you'll have something to keep you occupied while you're not allowed to drive anywhere!

--Ian

aidandj

iTrader: (5)

I change my belief. No idea what it is. Hope its coils. I marked the log right after they happen. About 5 of them

https://drive.google.com/file/d/0B7v...ew?usp=sharing

Whats interesting is the tach drops all the way to zero when they happen. Which leads me to believe its a coil issue.

My tach is driven by my coils.

I wish. They need rebuilds.

aidandj

iTrader: (5)

Definitely happens more when hot/warm. Got these logs after almost an hour of driving.

patsmx5

iTrader: (16)

Tach dropping to zero makes me think the coils are loosing power.

Your logs, when I plot fuel pressure, show the fuel pressure fluctuating when the misfire happens. So injectors are changing when this happens, despite ecu not commanding them to.

My conclusion: Something that supplies power to your coils (tach dropping despite MS staying syncd) and fuel injectors not firing (fuel pressure change despite constant PW during misfire). I think you can narrow down what I'm getting at from this.

aidandj

iTrader: (5)

I don't have a fuel pressure sensor installed yet. Those are bogus values.

18psi

iTrader: (76)

coils or cas
or perhaps the ms is resetting

aidandj

iTrader: (5)

Ms resetting should have been caught by log. CAS should have caused loss of sync right?

I'm banking on coils.

Currently going around and wiggling wires while idling.

aidandj

iTrader: (5)

Pulled some toe out because of miscommunication last time around.



Got the misfire to happen on decel. Does not show up on the log at all. Tach dropped to zero, but log shows perfect decel.

Replacing all the coils tonight, checking and cleaning all grounds.

If that doesn't fix it i'll be going over all my coil wiring with a fine toothed comb.

patsmx5

iTrader: (16)

Yes and Yes.

Does your MS get power from the main relay?

aidandj

iTrader: (5)

I believe so. If thats what it does stock. I'll grab a spare main relay too.

aidandj

iTrader: (5)

Here is the log of it happening on decel. Its the deceleration that starts at 1321s. As you can see there is almost no variation in RPM. The whole time the tach was bouncing of 0 and doing crazy things.

curly

iTrader: (25)

Well the MS gets RPM from the CAS I think, as long as the MS is powered and the engine is spinning, you could have 4 dead coils and it would still ready an RPM. I think. The tach is your issue, cause that's driven off the coil signals. Correct me if I'm wrong, but the coil fires when it's grounded? Or with a 5v signal? I've dealt with too many ground circuits lately. Why is that 5v/ground signal stopping?

aidandj

iTrader: (5)

The tach is driven by the tach output on the coil. Which is a different signal than the 5v used to fire the coil.

The tach ouput actually monitors the coil and only grounds if firing was successful. There is a 5v pullup connected to the tach output and tach so that the coils generate a 0-5v square wave

https://www.google.com/url?sa=t&sour...1z2nT9KW44-eiQ (4 wire coil)

aidandj

iTrader: (5)

So far so good this morning. But I won't know until I do a real drive this afternoon.