Hey everyone. I installed an adjustable fuel pressure regulator along with new injectors a couple weeks ago. Recently i noticed my car was very hard to start. So i tested the fuel pressure and i found that my car wont hold fuel pressure for more that 2 seconds. It goes from about 45psi to 0 almost before i can look at it. I thought that my problem would be one of the new injectors but i unpluged my vacume hose to the regulator and with the car on it started dumping out gas. Does that sound like it could be the problem? also, is it the diaphram in the regulator that went bad or just a bum regulator?

 

so i tried clamping off the fuel return line and my pressure didn't drop as quickly. Does that mean i need a new fuel pump?

 

have you tried clamping off the incoming line right after the pump primes the rail?? if you hold pressure after clamping then the check valve in your pump has gone bad...if it doesnt hold pressure then you have either a faulty fuel regulator or your injectors are leaking into the manifold. if you clamp the return line and it holds this pressure then yes your regulator is bad but id check both you could have more than one issue showing up.

 

what about gas coming out of the regulater vacume hose, that isn't normal right?

 

You either damaged the diaphram or did not get it in properly.

Fix this first, then drain and change the oil before trying to start it....in fact it may not be a bad idea to drain the oil now....