Standalone coil pack

[Eeyore]

ok guys bit of an update!

Swapped out the injectors, fitted the tu coilpack with ht leads, cleaned up the earths, took the omex apart to check for dry solder... no change!
In the mean time also swapped the thermostat out.
Took it up to carl chambers pre track day and still as stumped. sat their idling fine for 20 minutes with no issues and went for a drive and it misfired twice.
Next day brimmed the tank and no misfires. Seems that if the tank is more than 2/3rds full there are no issues whatsoever.

Only thing ive changed around the tank is fitting a new walbro 255 pump. Modified the housing to make it fit but that doesnt cause any issues.

What I guess could be happening is that the fpr is set so hard that there is no fuel being returned? the fuel pump housing has the external pickup bag and an internal bag as well which is where the returned fuel goes. If no fuel is being returned i guess it could be using up all the fuel inside the housing and then not drawing fuel in effectively. The housing has a hole near to the top so i guess when the tank is full it sloshes over the top and fills it.

thoughts?

googled image to show my thoughts...