Fuel smell under boost/cruising mz20 7mgte

[Kedderz]

Gday, another set of questions from a learning 7m'er

My mz20 when I drive with the windows down under boost and crusing I can clearly smell a fuel vapour smell. Its not strong as in taking a whiff of a jerry can, but its definately fuel.
Q: Does the toyota ECU run THAT rich that you should smell the fuel? or do I have a potiential leak from somewhere? suggestions of where the leak might be?

QI am fitting a SAFC2 this weekend then going for a dyno tune, should this solve the fuel smells I am recieving by leaning out the AFRs?

On the subject of fuel ive had my AC fixed (which is great) and now after about 10 minutes driving I get the fuel smell in the cabin, again weak but definately you can smell it.
Tonight i removed the interior carpets from the foot well and go in there with my nose to see if there was perhaps a "leak" or a decent opening for the smell to come into the cabin and the only place I found such a hole was where my boost gauge line goes through the firewall and into the engine bay. This already has a hose for god knows what and is located about 30 cm underneath the charcoal canister. This USED to be sealed with a rubber oring which sat snuggly on the tube and then to the firewall. Since the boost gague line has run through there this hasnt been present.
I have now just tonight plugged this hole up and removed the boost gague hose but left the hose which ends inside the engine bay in tact and driven for about 10 minuetes and NOT smelt the fuel inside the cabin with AC on, so hopefully that is that issue fixed.

[payney8]

check ur lines for cracks etc even if u cant smell it in the cabin anymore because of plugged hole its still not a good thing to have excess fuel in ur engine bay

[Kedderz]

definately not good I know, and when i install the SAFC2 and do the service + replacement of vaccum lines that will be the time to inspect the fuel lines, what im after is if there is a common point of failure that 7ms have which could leak fuel.

[thechuckster]

re-check the lines associated with the charcoal cannister - if that system is not being purged into the intake manifold while car is runnign (e.g. line form tank is left open at engien bay) you will get fuel odours with no discernable leak point.

It's possible that lines were shifted/unplugged while other work was being done.

[Kedderz]

well some extensive research I have come up with this ->
http://tsurf.no-ip.com/supra/DWT/Wrench_it/wrench.asp

And it definately has helped BUT! I need a new petrol cap, ne1 know where I can get one or compatible one?

--If you are smelling fumes inside the car then more than likely the little VSV valve
on the thermostat housing that one vacuum line from the charcoal canister runs to
and the other line from the throttle body runs to (the plastic piece that ALWAYS
seems to break just before smog inspection) has failed and is not allowing vacuum to
the charcoal canister to "remove" the vapor from the canister.
When the canister is disconnected is just eliminates the feed to the canister which is
why there are no more fumes. The fuel tanks in cars are vented to prevent pressure
buildup within the tank (not good).
The charcoal canister was added for smog reasons where as old gas tanks used to
have vented caps that would just vent to the atmosphere.
Newer cars have "sealed" tank systems and a vent hose on the top that runs to the
charcoal canister.
If you do remove your canister DO NOT plug the line coming from the fuel tank.
Leave it open (this is what I did where the metal line from the fuel !
! tank connects to the rubber hose just below the brake master cylinder. If you plug
the line,
1) You will NEVER be able to fill the tank up completely,
2) You will have pressure inside the fuel tank that can cause cavitation in the
fuelpump, and the least important
3) You can cause a potential explosion. :-) (OK if it is a Honda but not
recommended for a Supra).

Charcoal canister removal. The charcoal canister is the black cylinder that sits on the
passenger side in the back of the engine bay. It filters excess gas pressure so that it
can be vented to atmosphere safely. You can leave the line unplugged and very little
gas fumes will come out. Or, if you are worried about fumes, run some more fuel line
from there to a hole in the frame rail straight down from where the canister used to
be. Its covered with a plastic cap. Remove the charcoal canister. Plug up the vacuum
line that goes to the AFM bracket to the thermostat housing bracket to the throttle
body. You might as well remove all those lines and plug it up as close to the throttle
body as you can. This wont really do much except give you a little more space to put
stuff (its a decent location for a PCV catch can).