1991 corvette-chatted last nite ..replaced fuel regulator now wont start at all. question?? if you disconnect the fuel line at the filter and turn on the ignition will the fuel pump continue to run or will it just run a second and turn off??

Maybe pressure regulator

fuel lines hook up backwards problem solved...

Fuel Pressure Regulator is located on the fuel rail.

1. Disconnect the negative battery cable.

2. Properly relieve the fuel system pressure.

3. Remove the air cleaner outlet tube(s).

4. Remove any necessary components to access the pressure regulator.

5. Disconnect the vacuum hose from the pressure regulator.

6. Remove the pressure regulator attaching screws.

7. Remove the pressure regulator from the fuel rail.

To Install

8. Discard the O-rings on the pressure regulator and replace them with new ones.

9. Lubricate the O-rings with clean engine oil.

10. Install the regulator into the fuel rail and tighten the retaining screws.

11. Connect the vacuum hose to the regulator.

12. Install any components removed to access the regulator.

13. Install the air cleaner outlet tube(s).

14. Connect the negative battery cable.

usually caused by busted diaphram in fuel pressure regulator allowing fuel to be drawn thru regulator directly to intake manifold. Pull vacuum line off regulator, plug line with golf tee, start car and watch to see if gas comes out of regulator. If yes, turn off car, replace regulator. The regulator sits near the fuel rail on the top of the engine as shown below. I will paste replacement instructions below from autozone.com in case you need to replace the regulator. Please let me know if you have any questions.

Removal & Installation

4.2L Engine

1. Relieve the fuel system pressure.
2. Remove the air cleaner outlet resonator.
3. Disconnect the engine wiring harness from the retaining clips at the front of the engine.
4. Disconnect the fuel pressure regulator vacuum line.
5. Clean any dirt from the fuel pressure regulator and the surrounding area.
6. Disconnect the fuel return pipe.
7. Remove the fuel return pipe retainer.
8. Remove the fuel pressure regulator retainer.
9. Remove the fuel pressure regulator.
10. Inspect the regulator filter screen for contamination. If contaminated, replace the fuel pressure regulator.

To install:

1. Install the regulator filter.
2. Install the new O-ring on the fuel pressure regulator.
3. Lubricate the fuel pressure regulator O-ring with clean engine oil.
4. Push the fuel pressure regulator into the regulator housing on the fuel rail.
5. Install the fuel pressure regulator retainer. Tighten the regulator retainer screw to 71 inch lbs. (8 Nm).
6. Install the fuel return pipe retainer. Tighten the return pipe retainer screw to 71 inch lbs. (8 Nm).
7. Connect the fuel return pipe.
8. Connect the fuel pressure regulator vacuum line.
9. Connect the negative battery cable.
10. Inspect for leaks:
    1. Turn ON the ignition for 2 seconds.
    2. Turn OFF the ignition for 10 seconds.
    3. Turn ON the ignition.
    4. Inspect for fuel leaks.
    
    
11. Install the engine wiring harness into the retaining clips at the front of the engine.
12. Install the air intake resonator.

it should only stay on for a few seconds,you have an underlying problem.it could be either your fuel pressure regulator or the check valve in the pump itself might be letting the fuel drain back into the tank,im guessing the car only does it after it has been sitting for a little while and after the initial hard start it will keep starting normally,the easiest way to test it is to put a fuel pressure tester on it and start the vehicle or just pressurize the lines by turning the key on and see if the pressure drops,if it does, pressurize the lines again and crimp of the line from the pump wherever it is rubber with a pair of vise grips and see if it drop then..if it doesnt it will need a pump if it does it will need a fuel pressure regulator,im guessing this car has a L98 5.7 ltr TPI engine in it

put in neutrsl, jack up rear of the engine
release fuel pressure
use svivel socket to unscrew filter

Crank sensor!

39 pounds is not enough. Make sure the regulator is good, check for injector resistance

If there is not fuel going thru Fuel injectors, then it won't start. You can buy NOID lights at any auto store to connect to Fuel injectors to see if there is a problem with Fuel injector module. Here how the NOID lights look like:

http://www.tooltopia.com/index.asp?PageAction=VIEWPROD&ProdID=5334&utm_source=shopzilla&utm_medium=cse&utm_term=OTC3050C&utm_campaign=shopzilla_r1

You plug these into the connectors of Fuel Injectors to check during cranking. If there is light then your Fuel iinjectore Module is Good.
Then there is a problem with the Regulator. Here how it look like.

The fuel filter is located Under vehicle, passenger side, below seating area, front of fuel tank, mounted on frame in fuel line. It's pretty easy to change out. Please let me know if you have any further questions. Thanks for using FixYa!