Hi All,
Following happened recently on my car (1993 Cobra Mk IV AKL with EFI engine, under boot flat fuel tank, fuel filler on right hand rear fender)
- car parked in a steep parking lot (slope of about 10-15%), nose pointing downwards;
- tank had been filled up completely including filler neck just about 2 miles before the car was parked;
- about 10 minutes later, fuel started to run out under the nose (not by drips but by steady flow);
- quick check revealed that fuel ran out from the most forward of the 2 "mushrooms" covering the two large ports of the fuel vapor storage canister (sitting on right hand side in front of front crossframe);
- I assume that the two "mushroom" are ventilation covers;
Turned the car around 180 degrees, now tail pointing downwards and nose pointing upwards, and the leak stopped.
Left the car overnight. Next morning it started normally and worked without any trouble during the first 500 meters. The road then took a very steep hill (gradient about 20%) and the engine started to buck, like getting no fuel for a couple of seconds; no misfires and no afterburning; when reached the top of the slope and we were again running on more or less flat ground with more standard slopes up or down, the engine ran perfectly as always; no further sign during the whole day where I covered some 30 kms with multiple stops. And travelled 200 kms in the evening and 800 kms next day without the faintest indication of any problem.
I assume that the vapor storage had been flooded with petrol when the car was parked nose downward on steep slope.
Two hoses connect to the 2 smaller ports at the front top of the vapor storage assy:
- one hose connects the interior port (the larger of the 2) to a copper pipe running alongside the chassis rail (hence obviously starting at the rear end of the car, but so far I have not been able to look under the car and trace the start of that line);
this is in fact the return line for the vapours and is connected to the tank at its upper side behind the rear right side wheel (24/7/2018) - the second hose connects the exterior port (the smaller one) to the injection system.
Can anybody explain the function of this vapour storage assembly, and the flows of liquid or vapour? If it should be a simple vapor recovery or ventilation system from the tank, and should be principally dry, I would assume that the larger of the two small ports would be connected at some point to the filler neck of the tank
(see addition of 24/7/2018 above)
The image below shows the 2 large ports unvovered; on my car they have a kind of "mushroom" form cover. I'll take another picture tonight.
Grateful for any advice hereabout.
Many thanks in advance
Constant