The 87 GTA I have been workin on finally ran for the first time this weekend after fixing multiple fuel leaks and small issues.

However, when I turn the key to prime the pump, and then when the car shuts off I hear a loud metallic "swoosh" type of sound that sounds like the fuel rail filling with fuel. It happens both before and after I let the car run.

Has anyone experienced this that may know the cause. I doubt this would be "normal" to hear.

Thanks in advance

 

Nobody?

 

What is your fuel pressure doing?

 

When I hit the key and the pump runs the pressure goes up to 45 psi. When the pump shuts off the pressure starts to drop even without starting the car. Am I correct that this is a regulator problem?

 

And even if the regulator isn't holding pressure is it normal to hear a lot of noise when it first primes? My other thirdgen had a carb on it when I purchased it so this is my first "true" tpi start up and run.

 

How fast is the pressure dropping off?

If you pinch off the return line, does the pressure still drop?

 

With the return line pinched off:

Pump primes to 45 psi and holds
Car started and ran at 40 psi
shut off car and held 40 psi

after unclamping the line the pressure fell to 30 psi.

*This car also has 24lb injectors if it helps with diagnosing the issue.

 

That would indicate that there is a problem with the regulator. Possibly the diaphragm is bad.

 

Is there any place to get a decent price new regulator diaphram or should I try a used one?

 

we carry them. Don't buy used. Over time these things tend to dry out and crack.

SORRY FOR THE DUPLICATE POST!

 

we have them in stock. Don't buy used...over time they tend to dry out and crack

 

That's kind of what I figured