Vw passat 1.9 pd130 2004

Vw passat 1.9 pd130 2004

Hi everyone new to the forum
I have a vw passat 1.9 pd130 2004
The problem is it very slow at starting 10 seconds approx battery is fine new turning over fast
Sometimes it will fire up instantly and then cut straight out and then it will do that repeatedly until suddenly it will turn over for 10 seconds and then start
Have changed crankshaft sensor
Temperature sensor
Egr valve
All good quality
Have also tried with Temperature sensor disconnected

Only got a basic code reader but no codes
Any help would be appreciated thanks