I would start by replacing the fuel pump check valve. It allows fuel to flow only in one direction from the fuel pump. So, when you turn off your car the pressure doesn't decrease. But if this thing is dieing, then there might be a leak where after a day of sitting the pressure is slowly released and so when you get back into the car you need to crank it alot to get the fuel pressure back up.

I would also try the fuel pressure regulator. If this thing leaks then the fuel pressure will dies down in the same way and the pressure during operation won't be up to spec and the car might be a little under powered.

I think both of these parts are less than $20 from FCPGroton. When I replaced the pressure regulator it made no difference. When I replaced the check valve my car went from having to crank for 30seconds to starting in less than 2sec.

But if you suspect a pump you should check the current running to the pumps to make sure both are drawing the spec current.

Jim,
I am having THE EXACT same problem with my 1988 240. I suspect the pre-pump and am planning on replacing it. At the same time I think I may replace the fuel filter and see what I get from these changes. Anyone else care to chime in here?

If it's really poor on gas, then it's likely running rich.

Two causes of this (not the only two):

1) Failing fuel pressure regulator.

2) Bad connection at the temp sensor or a failed sensor (the two-wire sensor, not the one-wire sensor).

A bad sensor can mislead the FI ecu into thinking it's minus 100 degrees outside and send toooooo much fuel to the engine even when it's warmed up.

This can make very cold starting easy but can also cause flooding and/or hard starting on a warm engine.

An '87 might have a case of crumbling engine harness...


--
Don Foster (near Cape Cod, MA)