Pinging at low revs

[lexsmaz]

It could be a number of things but he does state that he is at Full load & so it would be WOT too, so its not No load its just low boost & lowish rev's at the time, so it still could be CR, but it would need to be a pretty high CR ..

[lexsmaz]

Didnt ask last night, but did you try backing off the load & bringing up the Revs & did it still ping then ?? or did you guys stop when you heard the Ping ..

[Roundy]

We did not try that no, we got out to double check the timing, only to find it had leaked oil from somewhere which is why the session came to a halt.

One thing I have just wondered, how does the ECU calculate the ignition to apply from the maps?

If the trace was smack bang in the middle of a tuning cell, would it use wholely and solely that number, or does it still interpolate from all the surrounding numbers?

[Cuzzo]

Firstly why tuning on month old fuel....

And yes id say timing too. Tdc with screw driver trick. Was any material machined off block or head? Timing markers could be out? You'd hope not enough to affect it this much though.

[jondee86]

If the trace was smack bang in the middle of a tuning cell, would it use wholely and solely that number, or does it still interpolate from all the surrounding numbers?

My understanding is that interpolation is used to obtain values when the trace is between cells. So if the cells were 2000rpm and 2500rpm and your engine speed was 2250rpm, the interpolated ignition value would be halfway between the values in those two cells. Likewise for the MAP values on the other axis.

Thus, if you could get the crosshairs right in the centre of the cell (vertically and horizontally) no interpolation would be required, and the ECU would use the exact value entered in that cell. Leastways, that is what I would expect

Cheers... jondee86

[Roundy]

Doing some checking on the weekend, the came timing on the exhaust is close, so not likely that is the issue.

However, Cylinder 3 is showing a very lean spark plug, with the others looking a bit rich.

So think that might be the cause, just need to figure out how to confirm the cylinder is running lean, thoughts?

[JustenGT8]

Borked injector? Pull them all and flow test

[jabbatron]

..........

[Roundy]

Flow test has all of them within 1% of each other up to 8000rpm...back to the drawing board

[jabbatron]

..........