What could cause Vauxhall Cavalier g reg petrol to cut out after 70 miles and then restart after a rest?

Answer 1

If the vehicle is carburated I'd suggest looking at the fuel pump in case it's "vapor locking". But if it's injected that isn't a possibility. If the vehicle is injected, carry a spare sparkplug with you and next time the vehicle cuts out, pull one of the spark plug wires and plug in the spare plug. Put the plug somewhere in contact with engine metal and have a helper crank the engine while you carefully watch the sparkplug. If you get no spark, you probably have a bad coil, ignition module or ignition pickup. If this is carburetter engine,it's likely to be the fuel swirl pot causing starvation.I have spent much time solving this.Look for a egg cup sized black plastic container with three fuel pipes on it.One incoming from fuel pump,one outgoing to carb.and one on top (angled stub pipe)returning excess fuel to tank.You need to remove this pipe and put a restriction inside it,I use a piece of steel bar,6--8mm dia. for a good fit depending on pipe size.It only needs to be about 10--12 mm long with a 1mm hole through it.This will prevent fuel returning at full pump pressure and starving the engine.