what engine, 16valves, or 8valves. silver top or black?
MPI or TBI engine. they sold both and are vastly different.
hums dont mean a thing, only that the pump can make noise.
pressure rules (and flow #1)
ive personally fixed every fail possible on these, stalls.
owned many and fixed more. (own 3 and restored them to 100% )
unfortunately this older car is not OBD2 level ECU/PCM.
so no scan tools work.
Ever give it a tune up.? at the 60k mile interval.? repeats?
1: spare parts, both filters. and timing belt?
2: EGR ,main loves to stick open if it does engine will stall.
starts fine , yes
does engine get to 180F coolant temp and hold? if not fix that first.
is engine idle at 800RPM, hot? y/n? if yes, EGR is not stuck open.
if lower, EGR stuck. or other probs.
not knowing which engine makes answers hard, and only generic.
not knowing the transmission option too, makes it hard. 3,4,5speed.?
the 3sp can have vacuum leaks that can be real bad for the 16v engine, see? see how the work together? or not?
3: bad TPS.
stalling happens for 2 reasons (not counting bad engine)
the ECU (engine EFI brain, puter. etc) does all it can to stop stalls
it has 2 slaves to do that. one is ISC other is spark timing.
when stalls happens this is a warning that the ISC is bad,
or is overloaded.
A: MISFIRE. Gross.( 50 reasons, but can be to rich or just needs a tuneup.)
B: bogging . Gross (too lean, or called fuel starvation)
does hot idle run at 800 all the time. RPM.
does engine have full power on hills.
does engine stall coming up to traffic stops (EGR malf)
does the lost power. recover, with just holding throttle down? only?
can you tell the difference from bog and misfire.
bog is lack of power, its smooth
misfire is violent, it shacks the motor. does it?
when you pump the throttle, this engages ENRICH mode
in the ECU , and overrides lean,.
my guess, (cant drive it and if could , i can tell whats going on)
but based on your inputs, it say its lean.
if power is low on hills, i then.
grab my fuel pressure gauge. $20
i do this at every fuel filter change, since im THERE already
it has a test port, a 6mm plug.
i take this hose and check for 30psi,
see why guess here.
34 to 36PSI, key on, 3 times, (both engines, not stated, so..)
see the tool here,for next to nothing. costs.
the EFI totally can no work at 20 PSI or hums.
it must be at leas 34psi.
below 28 the injectors fail. (read injector spec, and see that)
if the pressure is good there is hope.
post engine type, 4 injectors or 1.
and can go way deeper and more accurate.
bogging is here