Car randomly cuts out.

[Steveb50]

I have had a issue over the last 6 weeks. Car randomly cuts out. It will happen when engine is hot or cold. It could cut out 2 miles or 32 miles. It has always restarted about 15 mins later and then drives normal. (AT THIS POINT I HEAD FOR HOME) Most of the time before cutting out it will run lumpy for a few seconds, when I try to restart it fires but seems lacking fuel. After it restarts it runs lumpy for a couple of seconds and then back to normal. Things I have done over the last few weeks. I have changed the coil, petrol pump, replaced fuses and tightened holders (some were loose) cleaned all connections to coil, pump, lumenition connectors etc. Cleaned rota arm. Removed pipes to filters, petrol pump and carb, petrol seems to be flowing from them all. When it cuts out there is a spark. I am now convinced that the issue is in the carbs (muck somewhere) Any advice would be appreciated.

[StagJonno]

Have you looked at/ cleaned the contacts of the inertia switch - that grey cylindrical device mounted on the bulkhead adjacent to the fuse box? Easy to open up. Don't worry if the big ball is a bit rusty - it's function is purely to provide the physical movement to cause the contacts.

Grampian Stags have a good post on this https://www.grampianstags.net in the Tech Section.

[Lemp1953]

Hi Steve50,
Had a similar issue a few weeks ago after changing the float needles. all was well for a while and the on way back home from Hebden Bridge she spluttered and stalled then restarted then stalled again and no go. Smell of fuel and drips on the road. Trucked home and started first time out side house , since then I've had her running for 20 mins, no issues, but later a small drip on floor. thought I'd check inertia switch only to find i has been disconnected by previous owner. Going to clean it and reconnect and what see develops, could do with finding out what the pressure is from the pump as not sure if it's an original one, other suggestions I've had are to fit a fuel regulator with a gauge and set to the right pressure. It's an ongoing investigation Hope you sort it out , if you do p.m me with your results please
Mike

[Steveb50]

My car does not have a inertia switch. It has not had one since 2008 when car was refurbished and purchased

[threeleggedstag]

Well, I'm a newbie, so treat my advice with caution but we had this issue on the first run out once back home. It was pretty clear on opening up the bonnet that the fuel feed pipe had been led over the left rocker cover and under the air filter holder, trapping it against the top of the water pump cover. I guessed at vaporisation, changed the routing and no issues since despite a couple of half hour runs and stops followed by stops then longer runs. May be worth checking your routing?

[mallardstag]

My car does not have a inertia switch. It has not had one since 2008 when car was refurbished and purchased

You should fit one it's an important safety device.

[MikeParker]

I have had a issue over the last 6 weeks. Car randomly cuts out. It will happen when engine is hot or cold. It could cut out 2 miles or 32 miles. It has always restarted about 15 mins later and then drives normal. (AT THIS POINT I HEAD FOR HOME) Most of the time before cutting out it will run lumpy for a few seconds, when I try to restart it fires but seems lacking fuel. After it restarts it runs lumpy for a couple of seconds and then back to normal. Things I have done over the last few weeks. I have changed the coil, petrol pump, replaced fuses and tightened holders (some were loose) cleaned all connections to coil, pump, lumenition connectors etc. Cleaned rota arm. Removed pipes to filters, petrol pump and carb, petrol seems to be flowing from them all. When it cuts out there is a spark. I am now convinced that the issue is in the carbs (muck somewhere) Any advice would be appreciated.

Hi,
Sorry to hear of your troubles. First thing is to try and find out if it is fuel starvation, carbs or lack of spark.

You say it runs poorly before cutting out. Try pulling the choke as soon as the problem starts. If that helps it points to fuel supply.

When the engine cuts, try unscrewing both dashpots and moving them up and down. If you hear a "plop" of the carb piston dropping, then that is your issue (sticking carb piston).

If none of the above, try to simplify the ignition circuit. It is worth getting a 12V coil (e.g. Bosch blue coil) and then connecting a new direct 12V feed to the +12V on the coil. This removes any chance of problems with ballast resistors or ignition switching. It could also be your Lumenition not working. It may be worth getting a Powerspark unit or the like and trying that.

Sorry to be so scatter gun but it is just a case of playing around and trying to narrow down the cause of the problem. Please get back with any further info and we can try and help.

Mike

[1005hansjoachim]

Hi steve50
Sounds like the issue I had a few years back. I did similar fixes that you did. In the end there was a blockage in both carbs. Just a tiny white corn.
I suspect that E10 fuel dissolved the fuel filter which probably was ancient when I bought the car.

[DJT]

Hi steve50
Sounds like the issue I had a few years back. I did similar fixes that you did. In the end there was a blockage in both carbs. Just a tiny white corn.
I suspect that E10 fuel dissolved the fuel filter which probably was ancient when I bought the car.

There are some iffy fuel filters out there. A few years ago I bought a supply from a famous auction site. They started to disintegrate after 3 months using E5 fuel. I ditched the lot and bought some from a reputable trader at a local car show. They have proven to last at least 12 months on E5 and, so far, 11 months on E10.