[smaurno]

This is typical of an engine running too lean. When it's not under load, it will idle and rev fairly normally, but under load, it misfires and stalls. I'm not saying for sure that it's the fuel pump, but I would at least suspect it. The problem I ran into was that, initially, it was cheaper to change the part than buy whatever was needed to diagnose the problem. I changed the following before identifying the fuel pump as the problem:

EGR valve
EGR solenoid
coil
wires
spark plugs
cap and rotor
vacuum lines
fuel filter

The only reason I suspected ignition was that the problem got worse when it rained. By the time I was done, it would have been cheaper to buy whatever needed to diagnose the problem such as a fuel pressure gauge.