Pressure Drop & Petrol Fumes

[vuey28]

My boost readin seems to be always on -5 when on start-up and never goes above 0psi even when I rev the cow out of it. Is this because of the Blitz BOV? and my car just recently started giving off petrol vapours right out of the petrol cap area. Anyone know why? sorry if this is stupid to some but Im one of those people

Thanks all.

[Mumbo#5]

make sure u still have ur filler cap ... and i hope you dont mean free revving it cause you dont get boost free revving the engine??

[vuey28]

Hehehe... Yeah I still got the filler cap... Ill assume it itsnt screwed on tight enough... and of course Im not free revving it.... LOL... its while Im driving that it always stays below 0psi.

[R33S2]

Check for leaks. Was it boosting before BOV install?

[someonestolecc]

If you get boost (i.e. you can feel your car mumbo) and don't get it registered on the guage it shouldn't be your BOV (although it might be).

Are you sure you're gauge is plugged into the right place ?

[05YKO_r33]

My car has the same thing with the fuel vapour, when i have just started the car you can see the vapours escaping from the filler cap area. yes the cap is done up tight before somebody makes that comment again. i thought it may have just been a pressure build up from the the fuel coming out of the return line into the tank and vapourising a small amount therefore pressurising the tank and venting it at the filler cap. anyway that is my thoughts...

[Beer Baron]

the fuel vapour problem is a simple one. when your car was complied they installed a fuel neck restrictor. now, this fits inside your old filler neck and needs to be sealed in there with some kind of sealant. if this was not sealed properly or the wrong type of sealant was used this will cause vapour to leak out. you will notice that when you undo the cap you won't get the really strong ppssssssssshhhht noise as there is not as much pressure in there as there would normally be. best bet is to remove the filler and fix it. use defcon to seal it.

[Oosh]

This may seem like the a silly question at first, but humour me...

Despite these low readings does the car feel any different to drive (i.e. sluggish) ???

If not then it could just be a problem with the gauge, i once caused a kink in the hard plastic line under my dash while sorting out some wiring, all my manifold pressure readings were low and had me real worried til i worked it out.

It was badly kinked, so straightening it out again only partially helped, so i cut the affected area out and re-joined it with some silicon hose.

[vuey28]

Thanks everyone for your comments. Ill see what I can do now. First things first the petrol fumes first. I dont wana c my car go booom when some idiot smokes next to it. :lol:

I dont know if pressure drop occured before Blitz BOV came on. I got the car with it. Im basing my readings on the stock/standard boost gauge. So Im gona assume the gauge is plugged in right. Unless the guy who sold me it was playing around with the wiring. Lets hope not. Ive only had the car for like 1.5 months now. Thanks everyone much appreciated.

I cant compare from the stock BOV and Blitz BOV driving cause I got the car with the Blitz BOV. So Im outa luck I guess. I owned a NA R33 before this "but" thats not gona help

Thanks again

[DOUGMO]

I HAD THIS SAME PROBLEM,

IT WAS THE FUEL BREATHER LINE NEXT

TO THE FILLER NECK,

AND THE O RING AROUND THE SENDER,

ALL FIXED AND NO SMELL AT ALL NOW

[vuey28]

Hey, just out of curiousity... but do I need a mechanic for this job? or something I can do on my own? Did you do it yourself? Thanks

[Sydneykid]

Sounds to me like you have a vacuum hose problem.

The carbon canister removes the petrol smell. There is a line that goes back to the tank from the carbon canister. There is another line that goes from the carbon canister to the inlet, this sucks any fumes (after the carbon canister has cleaned them) into the engine and they get burnt. If that line is split or not connected, you will get pressure built up, as the fuel in the tank gets hotter. The cap then lets this pressure escape. Hence fumes around the cap

This could also be the problem with no boost, if you have a vacuum line off after the turbo, the boost will escape.

I find spilt vacuum hoses on Skylines all the time, that would be the first place I started looking.

cheers

[siksII]

yep on my old r33 the line on the left side of the plenum that connected to the standard boost sensor (that gives the gauge its reading) split just where the hose left the pipe off the plenum have a look at that. it made a hissing sound which led me to it.

[vuey28]

I havent found any leaks on any hoses coming and going from the carbon canister. Weird... Im clueless now. I see only 2 hoses going/coming from the canister. One of them splits into 2 which I assume you said one goes to the manifold and the other no idea. The other hose also splits into 2. Very confusing. Ive been inspecting the car for abit today and found white/creamy substances (not biological!!!) powder like in the engine compartment. Im going to assume the guy who last owned this covered up something. I got no idea. My day just gets weirder.

Thanks everyone for helping me. I learned alot in so little time. Thanks all. :lol:

Im gona get a panadol now. Headaches bloody headaches. Hehehe

Like all Skyliners... I aint giving up... LOL

[DOUGMO]

see if the smell comes from the cap area or

if it is stronger when you put your head under

the car behind the rhr wheel,

thats how i found the leak on mine,

removed the tank my self and sent the tank to

be cleaned at a radiator shop,