Crank sensor. Used to get this on one of my cinqs then used the crank sensor on my turbo and it done the same thing all good with a new sensor Whereabouts are you see if someone is local with a known good spare.

Edit just seen this has already been replaced. Was it a genuine one or aftermarket?

Thanks I have one coming tomorrow I have replaced it recently already and want to check if it is a duff I am going to replace the spark plugs too. I'm in Brighton East Sussex.

Bit hard to explain but there's a raised pip on the crank pulley the aux pulley has a hole which the pip goes into worth a check to make sure its on properly. Also make sure timing has been done right these have good tolerance to being out they will run OK with timing out but down on power,hard to start etc. I'm in Somerset if you get truely stuck and fancy a road trip

Good suggestions.

When I put my crank pulley on wrong with the pip not aligned it wouldn't start at all. Does the other position allow it to run poorly?

Never tried tbh maybe so. It just sets the ignition timing in the correct place in regards to engine timing the crank reads the missing teeth on the outer of the pulley so ensure this part is also clean no flakey rust etc and clean the area that the crank sensor slides through so it doesn't get dirty when installed

In the process of trying some of the above. Here's a better pic of the. Cable and connector the wire seems thicker than the ones running to the map sensor

If that wire runs to the D4 connector (inner wing chassis above gearbox) then it's for the air-con compressor supply.

Thanks I'm pretty sure that it doesn't have aircon although the heater has never got hot just blows air. Could it be for that?

I changed the plugs crank sensor and fuel filter today and it starts and runs (idles a little low and I'm not convinced it sounds as it should) ran up to temp fan kicks in and starts from warm so will use it and hope it's fixed the problem.
Now to find out what the mystery plug is for and then to investigate why the heater doesn't blow hot/warm air.

Thanks for all the help and advice so far.

Hope you have sorted the stalling. Sounds like it was the crank sensor?

I think the wire may be there on the loom in case aircon was fitted. A spare wire. Its probably tucked away on most cars? It looks nice and thick to provide power to something like that.

Has the cooling system been properly bled? There are two screws. One up on the bulkhead where the pipes enter and one behind the drivers headlight.

Has the heater ever been luke warm? It might be a clogged matrix?

Thanks purf yes the heater only ever gets lukewarm even with the system bled. I was going to flush it through this weekend especially as the head gasket had recently been done and looking at the color of the coolant reservoir it hadn't flushed through. I'll do some research in the guide section it can't be too difficult.

From my own experiences trying to unblock clogged heater matrix I would buy a new one.

At least its not too difficult to get at. In a punto mk2 the whole dash has to come out!

Thanks I have ordered one today. ?

Iv wasted a lot of time trying to flush one when it was blocked with rust. Even a pressure washer running through it didn't help!