Help with cold starting problem 1.4

[Rmachines]

The gauge often does work, as the ECU Sensor is the same part but separate outputs, usually shows on vag-com as intermittent fault, that is the coolant sensor and the only one, genuine isnt much more than after market, but tbh they all break after a few years anyway, so what ever is cheapest.  I cant see that causing this issue to such an extent to be honest but worth a try.

If i were you, i would pop the air filter housing off from the throttle body, and take a look down the butterfly, if your handy with the tools, take the throttle body off and clean everything up with carb cleaner if not, do it in place.   the AEX tends to produce massive amounts of mayo in the PCV system which dribbles down into the throttle body an gunks it all up, while your in there check all the pipes and hoses for leaks. The engine may run a bit funny after the throttle body has been removed unless you do the re-alignment with vag-com,  although it will correct its self with driving on these.   I would have said gunk in the throttle body is blocking the butterfly, preventing it to idle/start correctly, opening the throttle (pumping)  is introducing enough air to get it going.

[Only 1.4]

update
would not start when cold, when the weather warmed up during the day it would start no probs, new dizzy cap and rotor arm fitted, as the cap was a bit furred up, still no change, coolant sensor changed and it started but it wasn't a cold day. Took it out for a test drive and it wasn't running right put your foot down and it felt like it was going to die, felt like fuel starvation, new fuel filter fitted last sat morn, started straight away, although it was a warm day, prior to this had the air filter off to check for mayo in the throttle body and pcv pipes all clear, they are dry as a bone. Father inlaw tried to start it sun morning first thing no go, tried later in ther day when weather had warmed up and it started.

[Only 1.4]

o.k. guys this is getting really tiresome now, It still will not start cold, will start when the weather is warm, when the sun has been shining on the car for a while, I have changed the coolant sensor, dizzy cap, rotor arm, plug leads, fuel filter, even tried a different dizzy in it and still it will not start when it is cold, and not been warmed by the sun !!

PLEASE HELP !

[Greengolf]

Maybe its the Crank Position Sensor

[Only 1.4]

Where is the crank position on the engine ? The engine is a 1.4, the golf is an N reg base model.

[Greengolf]

Have a look at this post http://www.golfgtiforum.co.uk/index.php?topic=198567.0 gives you a good idea of what you need to do in order to change the CPS. Not too difficult, but need to determine if the symptoms described are similar to yours first.

[Only 1.4]

Greengolf thanks, I have read the post, Where will I find the crank sensor on a 1.4i ?

[Only 1.4]

Update, the latest is it idles anywhere between 600 and 1200 rpm and sometimes even cuts out, It now pinks when you drive it, new leads, rotor arm, dizzy cap, fuel filter what next ?