Hi guys... I have a 2002 V6 Hyindai sonata...
Bought the car second hand and was running great... Was told that car sometimes locks by itself so took ecu fuse out thinking this would fix it... When i put fuse back in car wouldnt start so took fuse out and put back in a car started.
Day after hubby degreased engine and wash it off with the hose... Since then car wont start in the morning but will in afternoon.
Got an auto electrician out and put obd on and threw no codes...He said one of keys were buggered... Bit started car later that afternoon will so called buggered key.
Then i thought it could be bacause i had both keys together for about a week and have messed something up.
Took it mechanic and they said crank angle sensor and cam sensor needed replacing...
Thats been done still no start.
So far have replaced crank angle and cam sensors, ignition coil, throttle body sensor, fuel pump and filter...
Will crank over but still no start.. Especially in the morning.
Can anyone give me some suggestion as i have read so much on Hyundai's and it seems to be a common problem with them.

 

Check the fuses again with a test light
There are two test points on the fuse.
If both sides have power then good fuse
If only one side has power then fuse is suspect
Sometimes the fuse may need to be seated properly (pin fitment issue).

If fuses check out good then back to basics
Check for spark, fuel delivery, fuel injector pulse, timing, etc

 

From what you have described, I would consider having a different shop , maybe dealer, check the vehicle. I say this because it seems whoever is doing the diagnosing doesn't have a good handle on where to look or check and is just replacing parts.

Can you tell us if there is a sizable temperature change between when the vehicle will not stat and when it will ?
If your vehicle has the immobilizer system, that would get my attention because something may be going on with that system

 

Have checked all fuse with test light and they are all good...
Yes my car does have an immobiliser...
I was thinking that may be the problem as I had the keys together for about a week while starting the car.
But if immobiliser is the problem i would suspect it would throw a code... And no codes have been found.. Which has stumped me.
When the auto eletrician came out he said the keys have to be kept separate..as i plays havoc on the immobiliser...
The difference in temperature between when it wont start to when it will is roughly 10 degrees...