911 won't start

[pbmitchell]

I have a 1987 Carrera Cabriolet which I've owned for 20 years. It's done
50,000 miles and starts on the button every time.

Well, every time except . . .

a) a few years ago when a relay under the left-side front seat became
loose

and

b) today. There's plenty of fuel in the tank and the battery is fully
charged but the engine just spins and spins without any sign of firing. It
was last started a couple of weeks ago when it ran perfectly.

I've checked the previously guilty relay and it's well-seated.

It has a Clifford immobilizer and I've tried clicking it on and off a few times. I've even disconnected and reconnected the battery but there's no sign of the engine wanting to fire.

Can anybody help?

[tr7v8]

You need to see if you have a spark & fuel at the engine end. Pull a plug lead off & plug an old plug in, see if you have a spark when you crank it. Pull a plug see if it it's wet. I suspect your imobiliser has imobolised it! You may need an alarm engineer to bypass the alarm. But first find out what exactly is going on. Are you an AA or RAC member they'll come out & do some diagnosis.