JohnGT6

Apologies - I should have replied earlier. In answer to your question, I found that the fault is replicated when on the drive rather than taking the car out for a drive and it breaking down at random points - less stressful because when it starts to splutter it doesn't take long to cut out completely! I also found that the car seems to run a little longer with the bonnet up and the air filter off (again possibly pointing to heat being concentrated between the air filter and the engine).  Holidays etc have got in the way but I intend to do the cold water test this weekend. Thanks.

Thanks for the very helpful suggestions folks. I tried opening the fuel cap but that unfortunately didn’t help. I like the idea of pouring cold water on the filter and the pipe work and I will give that a try. The filter is currently situated on the drivers side towards the front of the engine near the water pump.  It has been there for as long as I have had the car (20 years+) and never caused me any problems. These days the car spends most of the time gathering dust in the garage and this problem has only recently occurred. I’m left thinking that perhaps a gasket has degraded as there seems to be quite a bit of heat around the exhaust manifold (particularly behind the left hand carb) - although I don’t notice any noise that would suggest a leaking gasket.  I’ll try the cold water approach and perhaps an electric fan to keep things cool and see if it will run for longer when ticking over on the drive. I’ll keep the forum posted in case anyone else has this problem.  Thanks

Hello. Wondered if anyone could help with a problem I have with my MKIII GT6 please?  Essentially, it runs fine when started from cold but then cuts out when it gets warm. If I leave it for 30mins it will restart fine but then cut out again after a while. I initially changed the fuel pump, the coil, and reverted back to points from an electric ignition but the problem still remained. I then noticed that the fuel filter generally empties before the car cuts out. If I detach the fuel pipe between the fuel filter and carbs immediately after the car cuts out, there appears to be some back pressure in the fuel pipe. If I turn over the car with the fuel pipe detached after the fuel filter, the fuel is delivered fine. I suspected a problem with the float valve in the carbs and replaced both on the Strombergs but that didn’t help (one was sticking so I thought I’d nailed it but alas this was not the case). I now suspect a fuel lock it generated - possibly due to some potential heat escaping from the exhaust manifold gasket but I’m clutching at straws now. Before I start taking the exhaust manifold off, does anyone have any ideas or suggestions for me please? Thanks.