For the past 4 fill ups the fuel pressure has been insane so much so that I have to fill up before it gets to a quarter low cause it will make the throttle non responsive, the idle is fine so if I'm not near a gas station I will just release the fuel pressure and start the car and its run like normal. My first guess is that its the fuel pressure regulator. I could really use so good info guys. thanks a lot.

 

sounds more like an evap system issue, check that the charcoal canister isnt clogged up.

 

Try this, http://www.lexls.com/tutorials/maint...capgasket.html it might do the trick. I had some serious pressure, when the tank was low, until I did this.

 

Hey Dean, I don't understand this - isn't the excess gas meant to go through the charcoal canister, and the gas cap only meant to stop escaping vapors at low pressure? Replacing the cap seal would only increase the tank pressure?

 

"It's a special gasket that has a groove in it, probably to allow for some air to escape" quoted from the link.

the compressed/old one probably made the groves smaller/not even there anymore which will make for more gas build up.

 

^^^^ I don't know how it worked, it just did. When I did mine it was really an experiment b/c I was thinking the same. "How is this gonna work?" But it's fixed, no more pressure problems. I forget what I paid for the gasket, I got it from the dealer with some other parts.

 

Thanks guys I just replaced the o2 sensors and am getting much better mileage so it makes sense sort of. I will try that cause its cheaper than getting a regulator or damper.

 

I got a new gas cap today and it didn't fix the problem, still having an issue with surging while at idle and lose of acceleration while moving.

 

Checked for a trouble code to try to point me in the right direction but the computer says everything is fine,so I thought a vacuum line might be the problem but they are good to what else could it be.

 

The only time I've had an engine surging at idle was the engine speed sensor (crankshaft position sensor) on a disco2. It died a few days after that.

What if you leave the cap slightly loose for a few days and see what happens?