Technical bad cold start but great runner when warm

[rojjadojja]

im new to posting but have used other peoples postings for advice in past.i have a 1.4 stilo 54reg its done 110k.
my car has recently developed a bad starting problem, but does usually start eventually.
the computer prestart check comes up as OK.
as no fault codes garage is at a loss diagnosing but suggest sensors and £s
other posts have suggested crank angle sensor changed that no difference.
next changing water temp sensor. battery seems fine green spot etc.
I THINK something at first start up (ecu etc) is not receiving a message from a sensor saying this engines cold and needs choke (or injection equivalent).dont think its anything major hope not anyway
once its started it runs fine almost immediately and i regularly do a 200 mile trip at 75 ish and average 50 mpg even after starting problem .
any one got any ideas to solve problem properly or make starting easier by imitating choke (temporarily) whilst working on trying to solve problem

 

[Davren]

There's a guide to testing the temperature sensor here:

https://www.fiatforum.com/stilo-guides/104106-testing-radiator-fan-engine-temp-sensor-circuits.html

It also shows how to substitute the sensor for a potentiometer (variable resistor). You could use that to send a cold engine signal to the engine management ECU for test purposes.

 

[rojjadojja]

thanks for the advice my first reaction to POTENTIOMETER was i havent got one of those and couldnt afford it, im only a diy car repairer with a basic circuit tester and the old faithful bulb holder with 2 wires attached BUT thought id get more info if i could and now realise its basically just a switch with varying output and only costs a few quid on ebay.i can add that to my CV.its certainly a good idea and will give it a try. thanks

 

[fender kev]

I had the same thing on my cinquecento
it was the fuel pump