ok, so my setups is 255 walbro pump, 370cc z32 injectors, fuel pressure set at stock. turbo chargd 3.0.

Now, i am getting about 12MPG which is insane!
My air/fuel is fine, normal driving (traffic, cruising, not flooring it) I have a/f set at 14.7 or very close to it below 3k. above that is another story, how ever there seems to be something else wrong other than a/f mixture. I HAVE to be leaking something out of somewhere. Is it possible for the fuel tank to be venting fuel vapors out of the tank? I was thinking of getting rid of the entire evap system, however I am not sure if the gas tank is supposed to have a breather or a vent? if i remove the entire evap system, just line from tank to fuel rail, and thats it will that be a problem or do i need to have some kind of vent so that the tank wont build up too much pressure (depending on weather and heat outside). I personally think my fuel problem has to do with the evap. (btw we dont inspections in FL which is why i dont mind removing it)

 

It's the Gnomes!!!!!

No really .... the fule injection system runs on a pressure system, therefore no vents (other than the evap - which I understand vents back into the tank ??) Are you sure you don't have a leaky injector or fule rail? Also, had a problem like this once in a Stanza ... turned out it was my FPR being bad. $15 later saved me a LOT of mpg's!

 

may also be due to some cheap *** ****'s not wanting to pay for their own gas...hehe

 

how can i verify if my FPR is bad?

 

well honestly, if the FPR was bad it would or could leak fuel...another way to see if its bad is to remove the vaccum source supplied to the FPR and see if there is fuel coming of the FPR vaccum nipple. if there is then its bad cause the diaphram within the FPR has failed.. replacing a FPR is not a common thing to have to do just so you know.

 

well i got a nismo fpr, basiaclly its just like the stock one but with a nut on it to adjust

 

sure ur tank isnt leaking? my tank leaks when toped off. and i know because it has stains on it and i can smell it but the tank isnt damged and neither are the lines. so i still have no idea where the fuel is coming from.

 

wash the tank down with a hose and brush .... let it dry, toss flour, or baking soda on it to find the leak. Ya know ... like doin the fat chick, roll it in flour and look for the stuff that sticks.

 

How many miles does is it taking to get to 3/4 ? 1/2 ?
I really dont think your fuel is "leaking" out of your tank. Your car would stink if that was the fact man.

-matt

 

I had a 3rd gen that got terrible gas mileage and on the rare occasion I smelt fuel. Well I checked the filler neck for sighns of corrosion cause its common on jap cars but everything looked good I even went over the fuel lines and couldnt find the leak untill one day some *** cut me off and I had to slam on the breaks. The car slowed enough to avoid accident and than boom no breaks . Luckily it was 5spd so I slowed it to near stop as could be and came to rest without incident thank god. When I took the car apart looking for the failed fuel line I found a spot where 2 brake lines and the fuel line run together and what happened was the fuel line had a pinhole I missed while looking and the fuel leaked onto the break lines causing them to corrode rapidly untill excess presure was put on them and they burst. I only tell you this story so you really take a good look at those fuel lines . I would hate to see someone get hurt because of something I didn't say good luck finding the problem. Also I would check all the junctions on the fuel system sometimes the end can get malformed without you knowing.