[jkeyzer]

Kurt -

Thanks for the tip but that is the first thing I did in my extensive MFI troubleshooting. I have been through just about every piece of the system short of having the throttle bodies or pump rebuilt!

It is possible I don't have a gasket in the right place as there were no gaskets on my thermostat when I took it apart. I added one between the body of the thermostat and the pump cut out of sheet gasket material. After reading the literature it seemed like there should be one there.

Maybe I've got it wrong?

Aside from this problem it is running fairly well. I've got things synchronized pretty well by the book. I have a little bit of hesitation at part throttle once in warms up but if you really stomp on it there is a lot of power there. I'm also getting intermittent backfiring through the exhaust but I have an exhaust leak somewhere.