gas/exhaust smell when a/c on, 1994 wagon

[sixis12]

1994 wagon.

has gas smell when a/c is turned on, but not when heater is on.


EDIT:

did some more test driving (just got the car), there is a definate raw gas leak somewhere nearer the front end of the car. when driving you can't smell it but at stop/idle the smell comes through the AC vents, but not when the heater is on, assuming the air is being recirc'd when on HEAT instead of being drawn in the front when on ac (intake vent near the source of the smell)

the leak isn't enough to produce a visable wet spot anywhere, just a strong raw fuel smell.

all the hoses look like their in good shape, no apparant loose connections etc.

HELP!

[TaurusKing]

If you run your a\c on max mode, it'll recirculate the interior air, any smell then?? You may have some type of vapor line that is creating the problem, or some related part, solenoid etc..

[shorod]

I think TaurusKing is on the right track. You may have an issue with the EVAP system that is venting fuel vapors and your air intake is picking them up. You may want to inspect the hoses associated with the EVAP system. The engine vacuum diagram under the hood should show what lines and components are associated with the EVAP system.

You can also pick up some dye for the fuel system. It is the same dye that is used for some other fluid, maybe engine oil. The bottle of dye should say if it is compatible with gasoline or not. Add the proper proportion to the fuel system, run the car for a bit, long enough to notice the vapor smell in the cabin, then use a blacklight to inspect anything fuel related for traces of the dye. This will only work though if the leak is leaking raw fuel. If the leak is only vapor, I doubt you'll see anything.

Keep in mind that fuel vapor is actually what's flammable, not the liquid fuel. If you are smelling vapor, get it fixed ASAP, and use caution or a qualified shop when doing so.

-Rod

[sixis12]

no smell when the car is on max air

done some more poking around,

looks like the check engine light is not coming on at all, not even blinking at start up,

friend thinks its possible the computer is pooched and car running in default mode and the car is getting over fueled (really crappy gas mileage).

going on the scope in a couple of days to sort out engine light problem, will see what else developes

[TaurusKing]

Don't go wasting money on a new computer just yet,,, get the computer scanned, either buy a 30 dollar unit at the local parts store, they're easy to use, or have the autoparts store read it for you, and if any codes, post them here... I believe, someone correct me if needed, that if the car is running in some sort of default mode, failure effects mode or whatever they call it, it should show up in a scan???

[sixis12]

not buying anything yet,

getting it scanned for free to see if the check engine lite BULB is burnt, or if its the whole computer.

thanks for all the replies

[shorod]

There have been quite a few posts recently of others having issues with instrument cluster flex assemblies causing all sorts of goofy things to happen. It sounds like it is not too uncommon to have bad connections on the instrument cluster. Maybe the lights on yours are not working due to similar flex issues. Maybe you could pick up a salvage yard cluster for $35 or so and see if it acts any different. It's not too hard to change out, and 45 minutes of technician diagnostic time would exceed that amount.

-Rod