tkbennett1989

I have a 95 z28, it's a hard starter... It takes about 10 to 15 seconds for it to crank up. When it does it runs like a dream the throttle is responsive but there is a strong odor of gas near the back of the car and I originally just chalked it up to running a high grade of gasoline but now the pump is whining? What do you guys think it could be? Pump? Check valve? Regulator? Injector?

Injuneer

Check the fuel pressure. Should prime to at least 40psi, and when the pump shuts off after about 2-3 seconds, pressure should not drop rapidly. If pressure drop rapidly, will be harder to start. To check if this is the problem, cycle the key several times to prime the pump multiple times. If it starts easier after that, you have found the problem.

Could be the items you have listed. To rule out the injectors, pull the rails up, injectors intact, turn the key to "run" to prime the pump, and see if there are drips. A leaking fuel pressure regulator may result in wet fuel in the vacuum compensation line. Check for wet fuel. Could also be the regulator failing to close fully, allowing fuel to leak back to the tank via the return line. That is harder to check, because there is no easy way to block off the return line to see if pressure holds. Ditto with the pump check valve - closing off the supply line will help you detect that problem, but it's not easy to do. The dealer has a kit with valves that install via the quick connect fittings at the fuel rail hard lines.

Strong fuel odor at the rear of the car can be due to rotted vapor line from the tank to the carbon canister in the driver side rear fender. Hard to check, since on top of the tank. Or the canister could be saturated with fuel due to overfilling the tank. Or the EVAP purge system is not working.

gelbza

I would say the whining indicates the pump is probably weakening. I recently dealt with similar issues for a year, I'd replace the regulator first as it's relatively cheap and easy to do. There is a way to test it, but mine passed the test fine and yet was still bad. If that doesn't solve it, and there's no bad spark plugs or cracked wires, then go with replacing the pump. The easiest way is to cut an access hole (which I know several people are against, but I've found no issues with it and it saves a ton of labor, especially if you need to get in there again)

tkbennett1989

Thanks guys I'll take ya'lls advice. Thank you! I'll let you know