302C Running On when key turned off
Got a car here (Xc) with a 302C on petrol / gas,
When on petrol, and the motor is hot, you turn the key off, and the motor keeps running on, and 'pinging' as it does so.
It only does it on petrol, and when hot.
On gas its fine
Plugs are BP6FS and new
Fuel Pump has been replaced (the old one was leaking)
The motor was rebuilt some years ago, although its only done around 50,000kms
The possibility's im throwing around are
1) Some fuel in the sump, and its running on vapours
2) Possibly leaking intake manifold gaskets, and sucking air / oil
3) The fuel line and soleniod (gas / fuel cut) get hot when the motor is hot, the brass bit of the solenoid is to the point you dont feel comfortable holding it for too long, Therefore the fuel could be boiling in the carb and the motor is running on the vapour.
The thermaquad carb on it has been reconditioned to try solve the problem, but made no diff.
I doubt it is due to carbon deposits in the cylinders, it has had top engine cleaner through it and also given a hard run...
Any other posibilities or people with similar probs?