Hi guys, Just returned from a 2500 mile trip to Italy, where we've followed the Mille Miglia and cheered up a fellow F-chatter who was participating in a 1948 Fiat. The Dino held up incredibly well, keeping up with far more modern cars. One of the annoyances of this trip though was that the first 80 miles or so after refuelling, I could not take a fast righthander, or a LOT of fuel would be spilled overboard (like half a gallon in a long turn) Right under the fuel cap, there is a little tube inside the filler neck, connecting to a hose that exists below the car (right in front of the exhaust no less). In fast righthanders, fuel from the righthand tank will be sloshed to the left, and fuel will start spilling out of this hose. (Hose # 25 in the schematic below) I presume that this hose is for tank ventilation? A much more logical place to vent the tank, IMO, would be halfway the top cross-over tube (#22). This is a half-inch aluminium tube. T-ing this off and hooking up the vent hose there should make the whole thing immune to fuel puking. But before I start re-inventing the wheel - how is tank ventilation done on a 328?? These don't seem to have the puking problem that my early GT4 does... Italian engineering. Sigh.... Thanks! Hans Image Unavailable, Please Login
same Problem here ...81 GTSi simple solution ? I got used to not filling up ...always leave the last 3 gallons out
Pretty inconvenient. For starters, mine is by far the thirstiest car of the group anyway, and leaving 3 gallons out shortens the range even more (remember, I've just done 2500 miles in 8 days, this car is getting used), and how to know when to quick pouring gas in is another matter. I'd rather copy the 328 setup and solve the problem, rather than avoid it...
Very keen for a solution on this one too... Unacceptable for any vehicle to spew fuel onto a road surface especially in a corner, add water to this recipe and the guy behind you trying to keep up for a better look is going to career off the road! I was following a 240Z once (for a closer look) and mid corner about 5l of fuel shot out of his filler cap leaving me sideways with plenty of opposite lock. I caught up with him to let him know of the problem. Ironically he was a fireman in uniform and had left the filler cap back at the servo...
I feel that A solution would be to close the existing tank vent and add one halfway the top cross-over tube. This one is 3 to 4 inches above the top of the tanks to start with and should only carry air anyway. And even if fuel flows through that one (don't see how, really), then the placement halfway the cross-over would make it immune to cornering effects. But rather than that, I'd simply copy the 328 setup, since that works well. Anyone with a 328 care to give a description of how it's done there?
Have any of you chek if your fuel filling rubber tube is still in one peace? they age rapidly and most of car I know got cracked filling tube.
Hans not sure if you have already seen this but here is the spare parts diagram of the 328 fuel tank set up
Are you certain it is coming out of hose #25 and not the fuel filler neck or other top of the tank hoses on the drivers side?
Yep, on my 328 its exactly the same as in the picture above. It too will puke some fuel on a right hand bend if the tank is very full! I like your "revised" air bleed idea.
It seems to be originating from one of the overflow tubes that exit at the left-bottom of the car, just behind the rear wheel. These are the #25 hose and the overflow hose that is keeping the space outside of the filler cap dry. Since the cap seems to seal pretty well, I am assuming it's the #25 hose. It just occured to me that I don't even have to cut up that #22. What if I simply lengthen the #25 hose and reroute it to the passenger side and exit it there? Think about it, in corners that should do the trick too! I think I'll give that one a shot. Thanks for the link to the 328 system. Will study that one too.
Have you been able to inspect the hoses in that area? Have they been replaced? Has this been a problem in the past or something that has just started? I am wondering if jacking up the right side of the car (safely) would be enough to reproduce the symptoms. That way you could identify were the leak is coming from without the fear of it bursting into flames while driving. If this is the first time you have seen this happen it would lead me to believe that a hose, possibly #6 or #27 or #25, has a crack or puncture.
No, it's certainly not new. It has always been like this. Jacking up the passenger side makes a LOT of sense. Just fill up the tank (the gas station is only one block away), drive back and jack up that side. Good thinking, thanks!! I'll start with that. Hans
No problem. Remember to wait for the engine to cool before jacking it up. I am curious to see what you find.
Didn't jack it up as my lovely co-pilot for the day showed up before I got the chance. However, I am 99% sure that it is indeed tube #25 that is bugging me. It exits right in the "elbow" of the anti-roll bar, and right underneath the exit, it was very clear that dust had been washed away from the anti roll bar by some fluid, and a little fuel stain was there in stead. There was definately fuel coming out of that hose. I'll lengthen and reroute it to the passenger side. That way, in a righthander, the exit will be well uphill, preventing an overflow. Should work okay, I'd think...
No, it was probably 2 minutes before lunchtime when they got to designing the tank venting system and they remembered that there is that lovely Cavellino restaurant right across the road from the main factory gate...
Hey Hans is there enough room to rig a bottle to capture the fuel? That way you can take it for a spin and then check the bottle for fuel. If this is a design fault and not an old/leaking hose then I'd be very careful following a carbed 308 on the track.
If you're going to do this, be sure you route your new crossover tube with an uphill segment, otherwise you could wind up pumping fuel into the new hose on a right hander, only to dump it out the other side of the car when you straighten out.
