I've done some searches and could do with some advice...

If I return to my car after 3-4 hours it cranks for a while and then starts, it's as if fuel isn't getting through. It's an 03 WRX PPP with 55k.

When it does start (hot or cold) it doesn't immediately have the gusto, it hesitates for a split second and then revs at normal cold idle.

Has anyone had a similar problem??

I have just put a new battery on, it was a little dusty and fear the shop may have had it on the shelf for a while. If it was the battery, wouldn't I see this problem more at cold startup (when it is fine!?)

Any help is appreciated.

 

Sounds like crank sensor to me, they brake down when they get hot. once started, the cam sensor takes over the job so you'll only have the problem when the car is warm

does the CEL light come on?

 

Thanks for the quick reply.

I've not noticed the CEL light, any other things I can do to prove it either way??

 

Not really apart from substitution sorry.

 

water temp sensor can cause this problem when faulty as the fueling is less at the point of start up when the car is warm and more when car is cold like old chokes used to be.....so if the signal is giving warm when engine is cold start it will not be enough to start it properly, as is when hot engine, if it thinks its cold it will throw a load of fuel in on start up and may flood it so to speak...

old vauxhalls with bosh ecu systems had this problem and dealer would rip people off fitting new air flows etc etc and all it was is a couple o quid water temp sensor as it didnt come up with the 50 quid ecu diagnostic cheak

 

TBH, when the water temp sensor usually fails, it's harder to start when cold and the fans come on.

Just a thought, you could take the sensor out, stick it on the radiator for a bit, put it back in and try and start it

 

Crank sensor had this exact problem!

T