Road with a new fuel pump installed also new filter & relay pump cranks 65 psi pressure drops and quits, maybe if you crank long enough it might start, could this be fuel pressure regulator ?

no enigine told gas or diesel.
i cant see what you are doing
rules :
never run any pump dry, it is fuel lubricated and cooled.
if engine cranks and will not run (not told you)
then measure pump pressure only cranking, cranking matters. PSI cranking only matters, dead engine,.
some cars have key on prime pulse others do not. or based on air temps, yes/no. rules complex. avoid prime pump tests. (savvy?)
some new bosch pumps are 100% silent so noise tests are not good now, use use cranking PSI pressure only if wise. and hate taking a bath in fuel.
11vdc to pump pins cranked. (11vdc is battery resistance drop)
PSI cranked.
that is what matters.

below is battery voltage drop cranked, all 100% good
see the alternator wake-up, IT MUST./
11vdc cranked and 10.5 to pump (ohms laws Vdrop normal)

scopes RULE!

if it cranks at 65 psi the problem will not be in the regulator as the pump is producing enough fuel to exceed what the injectors need
What is happening is that the pump is not capable of delivering enough fuel to maintain that pressure when running so look for venting problems , hoses collapsing internally or blockage in the tank pick up

going backwards, ? (yes, i to check volts first) but...
you check fuel pressure cranking, (is press in spec or not?)
the FSM covers this, 1/.2 the cars only get pump activation,,
cranking and running, never just key on (the fsm shows this fact, i didnt look for you)
Yours is older loop system, not dead head.
there are 5 test just for the pump, (actually more)
pressure cranking and running, (leakdown test and injector balance tests and shut test for loop version) on V6 that 6 +4 ,10 total tests.
once the gauge is in place we do all 10s tests on v6.

ok say my pressure spec. is 40psi cranking and i get 10.?

spec: 32-40 running, pSI, vac, hose conn. (cranking will be more)
in loop systems the cranking pressure is about 10 PSI more.
after it starts, the vacuum sucks pressure from say 50psi to 40.
(its also altitude compensating)

Voltage checks, (any voltmeter)
use a voltmeter to see if full power reaches the pump.
i check voltage and its 8v. (bad) cranking volts can be near 11v due
to battery load, 200amps or so... what i do is measure battery crank
voltage and expect same to pump , using the 0.5v rule. (drop)
the connector over here to pump is all corroded. ,,
fix that and bam, now full presssure
or i find a bad fuel pump relay, replace that and bam.
or i find 0v, to pump.
i find relay bad. (simple tests on relay) (its not bad ECU)
ok i find 12v. at pump. so what is wrong?, i check my fuel pressure
regulator at the fuel rail, its stuck wide open because the shunt test
passed (one of 4 tests above) so new reg and bam, 40psi to rail.
i can test the reg with my hand vacuum tool that all shops have.
i can see pressure, running and cranking and check fuel pressure
with no vacuum (50psi?) then pump it to say 20 "hg (simulates idle)
and see 40 pSI, and check the diaphram for leak down.
my reg was bad.
there are other tests:
1: fuel pump current. (if excessive, its a bad pump)
2: scope test or use a current probe on pump and see it spiking
like made, , it has bad commutator and will die so.

there great videos on all this at. Duane's site.
http://www.youtube.com/results?search_query=fuel%20pump&sm=3

check the pump cranking

do not hot wire the fuel pump relay
if you slip 1/.8" you blow up a nice $400 ECU, (or more)
the ECU drives this relay (with a transistor, you dont want to explode)
if you feel compelled to hot wire things, disconnect the pump
and hot wire that.
now the relay.
it has 4 pins 12vdc in, 12vdc out to pump (contacts)
and 2 coil pins.
you put your meter to coil pins (across) i get 12v to coil cranking and running, that is the ECU working right
i get 12vdc in and zero out the contacts, the relay is bad.
lets say you see 3v out, that can be a shorted pump. or wire grounded out to pump. I check the current with my amp clamp and see 15amps
the pump is bad. most draw 4-6amps. normal.
i keep an open mind, what is bad, its only the pump 1/2 the time
or less. maybe 1/3? (reg, pump, wires and friends)
corroded connectors big time...some even burned up.

Was the problem there before you replaced the pump ?
The one way valve in the pump could be letting fuel pressure drop to zero. The fuel pump relay may be faulty too.
Have you checked the fuel pressure before and after cranking the engine ?

What is the condition of the plugs, wires & air cleaner? Also, what is the fuel like that's in the tank. Poor fuel quality will make an engine act like yours.

SOUND LIKE FUEL PUMP FAILED. FIRST CHECK REPLACE FUEL PUMP FUSE AND RELAY. THEN CHECK FUEL PRESSURE.SHOULD BE 25 - 65 PSI 4.6 ENGINE VIN CODE H AND 60 -65 PSI FOR ENGINE 4.6 VIN CODE W ENGINE 4.0 VIN CODE E THAT ALL FUEL PRESSURE SPECS. WITH NEW FUEL FILTER.

The s10 have a fuel shut off relay to shut off fuel supply in case of an accident. They also have a anti-theft system that prevents fuel in case of theft.Pull the fuel line off and crank the engine to see if you get fuel. Sorry I can't be of more help but without hands on vehicle it is hard to tell.Also your fuel pump maybe sounding like it is pumping. In other words it may be running but not pumping fuel it mat have a ruptured diaphragm in the pump.The pump is running but not pumping fuel. Pull the fuel line off at the fuel filter and turn on ignmition or crank the engine you should have about 50PSI coming out.If you don't install new fuel pump.These vehicles are common for this problem the fuel pump runs but does not pump fuel or not enough pressure these vehicle require 57 PSI to start if it has less than 51PSI it will not start unless you use starting fluid then it will run.It will run with less fuel pressure it will just not start with less than 57PSI.

Hope this helps

Did the engine just quit going down the road? or was it parked and then would not start? Did it have fuel before you replaced the filter? Did you check all the fuses in the fuse box. I think 2 of the fuses is marked ECM, check both Fuel pump relay? swap it with another relay in the fuse box. You should hear the pump come on for 2 seconds when you turn the key on, do you? If not as you are cranking the engine have someone rap on the bottom of the fuel tank with a mallet or block of wood, or hammer and see of the pump will run. If that gets it running, the pump is bad and will need replacement.

Check The Fuel Filter And Your Fuel Pump Its The Problem %99 Of The Time.
Sincerely,
Michael Scott

From what your describing this sounds like you have a bad fuel pump and should be easy enough to verify.Install a fuel pressure gage on the fuel rail. Cycle key on and check for a minimum of 50 PSI. Start engine and verify fuel pressure maintains at least 50 PSI during symptom.

If pressure drops, lower fuel tank to check for B+ on the Pink/Black (PK/BK) and good ground on the Black (BK) while fuel pump relay is energized. If OK, replace faulty fuel pump.
Fuel pressure should run between 50-65 PSI. Fuel pumps are a common failure item on this vehicle especialy during warmer weather.


lower the tank to get to your filter