9 replies to this topic

[Mr Apex]

When I started my NA after winter storage, it promptly dumped a load of fuel on my warehouse floor. Possibly as much as a litre suddenly appeared. Cue panic, switch off, roll car outside and wait for a safe period of evaporation prior to inspection. I couldn't find any obvious problems, so cautiously switched on ignition, fire extinguisher on standby. No leaks at all. Started the engine. Still no leaks. 1500 miles later, the leak issue has not reappeared. Still a worry, but I assumed that it must have been a system pressure problem.

 

Yesterday I switched on and the cabin filled with a really strong petrol smell. Switched off, jumped out, grabbed fire extinguisher and looked everywhere for a leak. No sign at all. Tried again after half an hour - same issue. The engine bay doesn't smell of fuel at all - the strong smell is definitely coming from the cabin.

 

Having looked at the system design and drawings, I'm thinking that fuel must be accumulating somewhere around the evaporation tank near the filler neck. Does that sound feasible? Any ideas what could cause it? How could fuel escape from that area?

 

Any ideas welcome before I take it all apart....;-)

[Nev]

When you switch the ignition on, a pressure valve connected to the evap/carbon canister switches position and to block (I think) vapour/pressure release from the tank. That vapour should be going to the inlet manifold, but I suspect maybe some pipework on it is cracked or broken and when the fuel pump surges pressure in/out of the tank initially, some vapour/fuel is finding its way out a broken pipe/joint.

 

Problem is, it's a rear clam off job to inspect it all. Arghhh.

 

Edited by Nev, 13 June 2017 - 03:52 PM.

[oakmere]

The fuel tank connections are in the cabin below the rear parcel shelf. It is enclosed but might be worth a look.

[Nev]

The fuel tank connections are in the cabin below the rear parcel shelf. It is enclosed but might be worth a look.

 

I think you could be right, even though it seems unlikely that they'd break/leak of their own accord, but would certainly explain why the smell is in the cabin.  

Edited by Nev, 15 June 2017 - 06:49 AM.

[The Batman]

Will need a midget to get there hands in there! Maybe worth replacing the fuel pump seal aswell

[Mr Apex]

The fuel pump was changed a couple of years ago, so that should be fine. I was thinking about sorting my fuel lines though - I currently run the original lines as far as the fuel filter, then braided from there to the rail. I noticed that Fezz had found quick release AN compatible connectors that fit the top of the canister, so you can run braided PTFE lined hose from there. Not sure how difficult that is though.... fuel tank out?

[Mr Apex]

Second thought - possibly the pump seal would not have been replaced at the same time as the pump?

[Spitfire Engineering]

Second thought - possibly the pump seal would not have been replaced at the same time as the pump?

 

It's unlikely this would have not been changed and certainly should have been.

Best to find the problem first though as it may not be relevant.

 

1 litre of fuel is a pretty major issue, maybe worth considering not using the car at all until it is identified and sorted.

If you take the under tray off you should be able to see some sort of tell tale in terms of markings as to which area the fuel is leaking from.

 

If you are getting a vapour smell then you don't want the car inside where the fumes can build up to a combustible ratio and the battery should be disconnected, again do this outside the garage.

 

[smiley]

I also had a leak once. Was a clamp. Drop the undertray and check near the filter.

Edited by smiley, 15 June 2017 - 11:04 PM.

[Mr Apex]

Thanks - I'll take a look. I'm keeping the car outside at the moment and being very cautious about checking for fuel leaks. I haven't seen any liquid fuel leaking since the original incident, so very tricky to locate the cause.