[hharney]

I have a new exchange fuel pump and throttle body on the front engine. In earlier post I had the fuel divider overhauled and still had the draining issue but worse than before it was overhauled. Sent it back to the repair station and they bench tested it and said all was fine. So that's when I sent everything, pump, throttle body and divider valve (injection lines and injectors) to ACI in Texas. They said that the throttle body was old and obsolete, had the wrong adjuster set screw in the servo, fuel pump was also obsolete (all these were original) and they charged me a bunch of money for new exchange units off their shelf. Well we got it all back together and low and behold the drains still leak. Post flight or engine operation, fuel will leak out of the cylinder drains. ACI did not mess with the divider valve because it was under warranty and they said their bench test was good.

The divider valve will hold 4 PSI under operation and 2 PSI while static. We put a gauge on the line from the servo and it reads just barley 1 PSI. We also left the line off the servo overnight with the fuel selector on to see if the fuel could be coming from somewhere else but there was not fuel leaking in that procedure. So after spending well into $2500 it still leaks. Yes I have a new pump, throttle body, divider valve, etc. but this whole issue started with the fuel leak that is still there. Next step is to send the divider back to the repair station and bench test again. It has to be passing through the divider.

On a second note, we did some fuel pressure adjustments too. It was suggested by the Texas shop to just verify their factory settings. The fuel pressures were low so we did some ground testing and adjustment. The one thing that is concerning is that you can't get full RPM on the ground. There is an correction table that provides multipliers for compensating but it only indicates to -120 RPMS max and I could only get 2550 RPMS. The procedure calls out 2800. Well that's -250 RPMS. We did some calculating and came up with the multiplier and set it. When we flew the aircraft it achieves the 2800 on take off but the fuel flow was pegged on the engine we adjusted. We turned it back down a little and I need to fly it again to see where it's at. Next month we are installing the JPI 760 with fuel flow that I purchased at Oshkosh this year. I really don't trust the fuel flow gauge in the panel for accuracy.

Anyone else ever have fun with fuel pressure adjustments?

And to end it all, I can't get my G5 power mac to start up, really weird thing going on there too.

Stay tuned.