Club Triumph

Hi All, don't know if this has been covered before but I am thinking of fitting plastic louvers to the bonnet to try to get rid of some heat, I am a little reluctant but I am suffering from fuel vapour lock (I think) , the car runs fine but after 3 to 4 miles I start to get an irregular misfire which gradually gets worse, I notice looking at the see through fuel filter, fuel looks low, then looking again with the engine off it can look full again,  I have just fitted another fuel pump (mechanical) as I thought that was faulty, the engine is not overheating as I have installed a very powerful electric fan, trouble is the fan when it comes on blows that much heat around under the bonnet everything feels hot including the carbs, all thoughts gratefully received so thanks in advance, Paul

As a trial measure could you try removing the rubber seal off the bulkhead to leave a gap and see if theres any improvement? 

hi glang, yes I have seen it mentioned that someone on here did remove a section of the seal to try to improve the problem but don't know the result, thanks for reply, Paul.

I tried it on my Vitesse just to improve general cooling and didnt notice much difference except for engine fumes coming in to the cabin from the ventilation intake

dont know what happened there as half my reply disappeared! However carrying on: Instead I made some other changes including a new rad and am now very pleased with the temperature control.

More detail would be helpful, but on the face of it that doesn't sound like classic fuel vapourisation to me - that would usually occur when trying to restart a hot engine or possibly when moving slowly in heavy traffic. If that's not the case I'd suggest looking elsewhere first. For instance, there are a good many dodgy aftermarket rotor arms out there that become conductive when hot and cause misfiring.

are right, accuspark fitted new with rotor arm and power coil, timing done at 6 deg btdc and re-checked, advance vaccum working ok from carbs, spark plugs correct grade and read a nice auburn colour, engine temp normal all the time as power fan comes on when needed, it used to over heat until fitting of alum rad and unblocking of water ways, power fan creates the heat under bonnet, so engine overheat is not the problem, new mechanical fuel pump fitted, my thought on fuel vapour lock is mainly because when the rad fan comes on (which is a sucker fan) the heat that it blows from the fan when on is a lot and its blowing onto the fuel pipe that runs round the front of the engine and the fuel filter,  carbs are getting hot (HS6's) especially the front one, I do have heat shields on them, as I mentioned before the fuel filter (see through) sometimes seems low in fuel another time seems full, now I have stopped the car engine off the fuel looks low in the filter then going back sometime later without touching the car the filter looks quite full as though fuel has come though as its cooled off, strange eh, thoughts please, Paul.

Where do you have the filter located? You said this happens after 3 to 4 miles but surely the rad fan hasnt come on so quickly? As Dan says what happens on a hot restart which is when youd expect the worst heating to have occurred?

Hi all, I have delayed in replying as I have now sorted the problem fitted new spark plugs, fuel system is now electric pump and filter in the boot with braided hose running offside straight to carb, I also realized the accuspark coil should not have a voltage stabilizer, they do 2 types a red or blue coil, blue is with stabilizer red not, they had sent me a red, I believe this was the main cause of the problem, removed the stabilizer altered the wiring and now she runs lovely,, another mystery solved, thanks for all your replies, Paul.

Hi all, I have delayed in replying as I have now sorted the problem fitted new spark plugs, fuel system is now electric pump and filter in the boot with braided hose running offside straight to carb, I also realized the accuspark coil should not have a voltage stabilizer, they do 2 types a red or blue coil, blue is with stabilizer red not, they had sent me a red, I believe this was the main cause of the problem, removed the stabilizer altered the wiring and now she runs lovely,, another mystery solved, thanks for all your replies, Paul.

Hi all, I have delayed in replying as I have now sorted the problem fitted new spark plugs, fuel system is now electric pump and filter in the boot with braided hose running offside straight to carb, I also realized the accuspark coil should not have a voltage stabilizer, they do 2 types a red or blue coil, blue is with stabilizer red not, they had sent me a red, I believe this was the main cause of the problem, removed the stabilizer altered the wiring and now she runs lovely,, another mystery solved, thanks for all your replies, Paul.