[Ether]

Hi Al,

Thanks for jumping in here.

This car spent its entire life in North Carolina and Florida until a couple of years ago when my mother stopped driving and gave the car to us. My daughters flew down to Florida and drove it back up here. I asked them to keep all their gas receipts, which they did. I was quite surprised (and pleased) to see that it got over 26 mpg on that road trip.

So being from the south, there's no rust and very little underbody or engine compartment corrosion.

If the pump is strong enough to supply the necessary flow and pressure to start the car and idle it smoothly for a few seconds, it's not clear to me why it wouldn't be able to keep the car idling.

So my working hypothesis is that the fuel pump itself is fine, but it's not being controlled properly once the engine is started.

In my previous post I attached a screenshot from the Chilton manual for this engine, indicating that fuel rail pressure is regulated by the engine control computer adjusting fuel pump speed (I assume by pulse-width-modulating the supply voltage).

That's why I asked question #3 in the original post. Does the engine computer for this engine have a parameter ID (PID) for the fuel rail pressure sensor? If so, I can borrow a scan tool and see what the fuel rail pressure sensor is doing.