Starting problems
 

Hi have an 05 plate v50 with starting problems sometimes starts everything no issues then you can go back and take 5 mins to start then be fine again. With a lil bit of reading ignition switch seems to come up.alot ? Vovlo want 140 to put on computer but I don't think it will.show anything as there's no codes up on dash many thanks

Hi
What engine??
With the 2.0 D :- Generally with the ignition switch the engine won’t turn over and sometimes get “key error” message.

There are issues with sticking flaps in the throttle body. If one sticks shut it can fail to start.
Also there have been issues of cracked fuel filter housings and/or leaking o rings on the fuel line connectors.
I assume your engine turns over but doesn’t start??
Probably not the ignition switch.
Try the air flaps first and then for air leaks in the fuel system. There is no lift pump on these engines so any air leaks in the fuel system and fuel can drain back to the tank and cause starting issues.
Loads on the forum about the air flaps, just do a search.

Yes, +1 to what IainG wrote and also if you have a cheap Bluetooth obd reader check codes, bad cam or crank sensors can cause time to time not-staring problems.