95 blazer 4x4 4 door w vin 4.3 v6 ignition problems
4.3L , L35(RPO engine)
has 1 fuel pump relay PCM controlled
has 1 fuel pump.oil pressure sensor , too.
not sure at all me what a pulsator might be.Ahh Dampener.
what matters is spark first, it must have spark or the PCM cuts fuel dead on all EFI car. (if the PCM detects spark bad in ANY WAY)
the comes cranking the pump just receiver 12vdc cranking
KEY ON ONLY is only 2sec prime puls best is forget that unless have 2 person to test prime, but cranking matters first.
some new pumps are silent, (like top Bosch) so sounds prove little. today what really matters is PSI pressure cranked,
the PCM brain or the oil pressure switch allow the pump to have power cranked, and running.
that is how to test it, cranked only.
"starting with start fluid,but now it just cranks over ,only."
does this mean starting fluid now fails.?
we check spark at all spark plugs no just 1.
we check oil pressure to, if zero PSI cranked that is bad .
last is fuel pressure if not at spec, it will not start.
spec fuel pressure is 58-64 psi
yes some fuel rails or near by or near tank, have pulsator that is really regulator/dampener.
it prevents old cheap pumps from madly pulsing the rail and causing injectors to mess up. vane pumps do make pulses some worst tan others, (some even by pass it, but there is their call)
Is this a TBI throttle body injection? or MPI.
the SM states this. (it has a 2 second prime for sure)
If the engine does not run, turn the ignition ON, but do not attempt to start the engine. Listen for the fuel pump to run. Within 2 seconds of turning the ignition ON pressure should be 58-64 psi (400-440 kPa) while the pump is running. Once the pump stops, pressure may vary by several pounds, then it should hold steady. If the pressure does not hold steady, wait 10 seconds and repeat this...