fuel tank pressure? is it normal?? help please

[300ZXttZMAN]

hello my name is mark i have a 90' 300zx twin turbo i have a idle problem only at normal opperating temp and im running really rich i have changed plugs. I have heard that its possible that the fuel tank being pressurized could have something to do with idle im not too sure if its a pressurized in the tank or vacum (suction)

thanks in advance

[txQ45]

If you have someone around you with a Consult, Nistune,,etc .. you could check the sensors, maf, injectors etc.

[300ZXttZMAN]

would the dealer have that??

[300ZXttZMAN]

does your fuel tank preasurize

[robomatic12]

Err... I don't think you are quite on the right track with this fuel tank pressurization thing... If you have an idle problem suspect the IACV valve being clogged, or perhaps a vacuum leak. This also goes for your rich condition. Check the 6P's (search) and check the ecu for any codes.

[300ZXttZMAN]

OK BUT IF THE FUEL TANK IS NOT PREASSURIZED AND NOT ALLOWING FUEL TO GET TO THE MOTOR THAT COULD CAUSE IT TO RUN POORLY BUT IS ANYONE ELSES TANK PREASSURIZED IT MAYBE NORMAL

ANY HELP IS GREAT

[itsa300zx]

The only time my tank gets pressurized is from the heat in the summer. The fuel pump it self should not pressurize the tank. Get a fuel pressure gauge and hook it up after the fuel filter to see if thats your problem.

[Ace2cool]

ALL CAPS DOESN'T REALLY HELP GET YOUR POINT ACROSS ANY BETTER THAN WHAT HAS ALREADY BEEN STATED. Try to tone it down from now on, thanks.

As far as your problem, sounds like some kind of a vacuum leak. Could be the IACV, as previously stated, or any other metal intake mating surface. On my last car, I had a "bouncing" idle, caused by loose bolts in the upper intake plenum letting air in past the MAF sensor.

A little more description than "idle problem" would also be helpful in diagnosis. The pressurization of the gas tank has absolutely no effect on the flow of fuel into the engine. That's what the fuel pump is for. Post a little bit better description of your issue and I'm sure we'll be able to help you better.

[adambullet]

The only time my tank gets pressurized is from the heat in the summer. The fuel pump it self should not pressurize the tank. Get a fuel pressure gauge and hook it up after the fuel filter to see if thats your problem.

hey thank you for this tip. i am also currently undergoing pretty much the same issues with my fuel tank and fuel pressure gauge.

[Ace2cool]

....On your Mazda 2? J/k man, we're here to help.

If you're talking about a Z32, you mentioned a fuel pressure gauge. You have an external gauge hooked up? What's the pressure reading on it?