I have been having starting problems. after the first start it's ok the rest of the day. This is a follow up to a post a couple weeks back. I have a guage now, and, I have fuel pressure 40 lbs at start, and 30 lbs running. Is this ok? Someone suggested a fuel pressure regulator. Will a pressure regulator have intermittent operation, or fail completely? Should I just change it after 11 years to be safe. Thanks for any help Stan

 

There is a test for fuel pressure regulator .
Pressure should be 28-30 at idle, 38-40 with vacuum hose disconnected at the pressure regulator.

Disconnect the vacuum hose at the regulator and watch the gauge. If it doesn't change, and if there is vacuum on that hose, the regulator is bad.

Good luck,<!-- / message --><!-- sig -->

 

I have 30 lbs. without the vacuum disconnected to the fuel pressure regulator. I removed the vacuum hose at the fuel regulator, and the pressure went up to 40 lbs. I still have vacuum at the hose I disconnected. I reinstalled the vac line and the pressure went back to 30 lbs.
does this sound right? Stan

 

It seems pressure regulator is functioning correctly .

Have you changed your "fuel filter" lately ?

The other thing to check is Idle Air Control Valve (IAC) . That has to do with "cold starts" . To test it :
Hold the gas-pedal down 0.5-1 inch and see if it starts up and runs right , if so , it is the IAC .

If it turns out IAC is the problem , then make a search about its location and how to clean it . (By the way ,if you have a K&N air filter , it may be a good time to get rid of it , back to stock ).

Good luck,

 

I thought K&N were the way to go. I don't have one. I did change my fuel filter. Stan

 

K&N uses an " oil wicked " filter element . That creates problem at downstream sensors . The oil droplets carried by air-flow gets stuck on MAF (mass air flow) sensor , IAC valve and throttle . Their function suffers .

Do the suggested IAC test above . If that is not the cause ,you may take your question to V-10 forum for other ideas/suggestions.


PS. Did you check fuel pressure "under load" ? ( let's say @1500-2000RPM) . Pressure, should be 28-30 psi at idle, 38-40 psi at high load (or disconnect the vacuum to the fuel pressure regulator at idle, and it'll go up to 38-40).


Good luck,