11Budlite Posted April 24, 2008 Posted April 24, 2008 All, I've been having a blast driving the Birkin to work and some quick pleasure drives. I've made a few adjustments to the Emerald map to get rid of a rich running condition on low/no load sites and fixed a couple moderately lean conditions at some higher load/rpm sites. One thing I haven't been able to correct is a fuel smell from the back of the car that I can't trace to a visible leak. I have a Fuel Safe fuel cell that I installed and plumbed the same way the original Birkin tank was installed. Here's a couple pictures of the installation and fuel vent cannister. The small filter is actually hooked up to the rear end breather. http://www.usa7s.com/aspnetforum/upload/316676069_20080425_0001.JPG http://www.usa7s.com/aspnetforum/upload/459852140_20080425_0006.JPG I'm seeing some fuel in the clear hose from the check valve (on the lower left of the 1st picture) going to the fuel vent cannister after driving. Since I believe this is a roll-over shut-off valve, I think that could be normal with a full tank. The fuel has gone over the top of fuel cannister and rested in the bottom of the loop but when I removed the fuel vent cannister, I didn't see any fuel collected. What I was wondering is if I'm doing anything obviously wrong that would be causing the smell. I was thinking of turning the check valve around 180 degrees, running the vent line up the left inside of the rear bodywork, back down again after a 180 degree loop and then continue the existing route to the fuel vent cannister. I was hoping that might keep some of the fuel from making it to the cannister. I was also concerned that the fuel return that's hooked up to a bulkhead fitting in the fill plate was causing some problems when the gas was being dumped back into the fuel cell, so I made up a 3/8" line to take the fuel closer to the bottom of the bladder between a couple of the foam blocks. Here's a pic of the fill plate with line: http://www.usa7s.com/aspnetforum/upload/146872848_20080423_0003.JPG Maybe I have a leak that I haven't located yet, but if anyone has some advice on my installation or helpful links I'd appreciate it. Thanks, Bruce :7drive:
slomove Posted April 25, 2008 Posted April 25, 2008 Whoa, this is an issue that has plagued me since I got this fuel cell (I have the same one). I think the problem is because the flap in the filler neck can shut really airtight and the sloshing fuel may sometimes surge into the vent line. I tried to fix this with a tiny check valve in the vent line which works very well to prevent fuel from dribbling out but it allows for pressure buildup in the cell when it gets warm outside. After I got sprayed all over with fuel when filling up (no fun) I removed the check valve. I finally punched a tiny hole (maybe 1 mm) into the filler flap to allow pressure equalization and added a vent line to the filler neck (connected to the left-hand-side vent line and the breather with a tee-fitting. That works pretty well so far. Unfortunately the cell has now developed a weeping leak somewhere else. I heard that pinholes are quite common. It is very little and I ignore it for now. But with 5 years the design life of the bladder is up and I should not complain. Gert
Al N. Posted April 25, 2008 Posted April 25, 2008 Bruce- As you know, I don't do any of the work on my own car, but here's what I know about how my cell is rigged up...my rollover shut off valve/vent was run up my roll bar and terminates pointing down...when I asked the mechanic about it he said, that's if you roll over... Don't know if this helps at all, but I do know that the open end of the vent is at least 2 feet above the fuel cell itself. I don't notice a fuel smell (from that particular region of the car, at least!). We can compare set ups at Carlisle if you are going out... -Al
11Budlite Posted April 25, 2008 Author Posted April 25, 2008 Thanks Gert/Al. I'm going to do a more thorough check for leaks this weekend and play around with the vent line routing. You don't smell it when driving, but after leaving it parked in the garage you can definitely smell it....:ack: Al - Did your mechanic run the vent inside the rollbar? And yes, I(we) plan on being at Carlisle WITH the Birkin! Thanks again, Bruce :7drive:
Al N. Posted April 25, 2008 Posted April 25, 2008 Bruce- The only smell I notice in the garage once in a while is coolant (I don't think I've hooked up my raceline water rail exactly right...another thing we can compare at Carlisle). My vent hose is attached to the outside of the rollbar (the right side upright) with zip strips...the hose itself seems to have some sort of rigid liner so that it doesn't deform under the zip strip. The wire to my wolo light bar is run up the right hand support bar. See pic below... http://www.usa7s.com/aspnetforum/upload/1923877586_Cat Bar Detail.jpg
WestTexasS2K Posted April 25, 2008 Posted April 25, 2008 If you have a remote check valve that should be mounted vertical with the hose on the bottom. This allows the valve to be open and vent tank pressure. In case of a rollover the valve shuts and prevents spills. Mounting them horizontal or upside down keeps them from working properly.
11Budlite Posted April 1, 2009 Author Posted April 1, 2009 I'm doing a little maintenance to my fuel cell (replacing gaskets/checking the foam blocks/etc) and have it completely disassembled other than the bladder is still in the can. It seems at first look that it's going to be a PITA to get the bladder out of the can. It looks like I'm going to have remove the nut plate assy's (they seem to be lightly glued to the bladder) to be able to fold the bladder enough to get it to fit through the 6 x 10 opening in the front of the cell. Has anybody done this before? I don't want to damage anything but it'd be nice to give the outside of the bladder a quick look for any issues while I have it this far apart. Any advice would be appreciated, thanks.
slomove Posted April 1, 2009 Posted April 1, 2009 I took it out when I had the pinhole leak and inspected from the outside. Did not find anything and put it back in. Yes it is a pain in the @rse. Especially if you cross-thread the bolts in the soft die-cast alloy of the bulkhead frames. Anyway I still have the pinhole leak and it still bothers me but I am not going to invest $1200+ right now. Gert
11Budlite Posted April 1, 2009 Author Posted April 1, 2009 Thanks Gert. It sure would have been easier if they made the top of the can removable.
11Budlite Posted April 5, 2009 Author Posted April 5, 2009 I took it out when I had the pinhole leak and inspected from the outside. Did not find anything and put it back in. Yes it is a pain in the @rse. Especially if you cross-thread the bolts in the soft die-cast alloy of the bulkhead frames. Anyway I still have the pinhole leak and it still bothers me but I am not going to invest $1200+ right now. Gert Gert - I ran across this repair kit when I was checking out Fuel Safe parts availability. It might be worth a shot to fix the pinhole leak. Here: http://www.hrpworld.com/index.cfm?tpc=Fuel_Safe_Bladder_Repair_Kit&form_prod_id=267,100_4523&action=product
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now