Originally Posted by kb8ymf
Thanks for bringing me up to speed. Now this is a whole different issue.
Flat gound? WOT only? how full was the tank? Could it be slosh like Casey is suggesting because of lack of fuel?
If that pump is only capable of 48ish thatISbe the issue. Can you get it to repeat? he has said it repeats Put a gage on it while it's running.he posted that info yesterday This one should be pretty easy to see.
You may also need to view the O2 sensor signal. If you're not seeing a good signal it may be leaning it out. Again a good streaming TechII will allow you to look at A/F ratio and injector pulse width and see if it's being 'told' to lean out or the fuel pump pressure is just low. I'm suspecting the latter as Whiterhino had a similar problem I believe a few years ago and a real pump fixed his problem. You also said your pressure was not up in the 60 psi range.
These engines require more than 48 psi. period.
Nothing else will cause the low pressure at the rail.