If the dieseling becomes a problem, you might consider fitting an anti-run on valve. Fitted as standard to the MG Metro,(and other BL cars) it's a simple solenoid, energised by the ignition, When switched off the valve opens and dumps air into the inlet manifold. It has a swiched live terminal, an earth terminal and a servo hose connection which must either go via a T piece into the brake servo hose, or if you don't have one, into the inlet manifold direct.
