Intermittent problems starting 172

[172_Bec]

Afternoon boys and girls
Having problems with my 172.
First thing in the morning, car starts straight away no problems. Then when I go to start it again (either after 10 minutes or 10 hours), it takes about 10 minutes to start. Key in ignition and it just will NOT start. My other half tried to bump start it the other day and it didn't want to know, then after a couple of minutes of sitting and swearing at it it started. Runs fine when going. Definately worse after its been driven the first time in the day.
Battery is fine
New spark plugs
New air and fuel filter
and oil change
Getting worse and more frequent (the car and my language!!!!)

Any suggestions greatley appreciated
Cheers

 

[wingrat]

My Mother has a similar problem on her 1.4SI (1999). The car start most of the time but on occassions turns over but will not fire. I need to investigate further to see if the Immobiliser is turning off once the key is inserted.

Have swapped keys around but still suspect.

Would be good to have a definitve list of steps to check as I seee many other peiple having this issue. Some mention keys, some CTS ?

Anypne ideas to start with and not having to go and buy new keys yet..

Tony