Need some advice help please lol

[Joey95309530]

I have a 2001 tt Quattro 225. I've put new fuel pump,new fuel filter new injectors and new fuel pressure regulator. And still can't figure out the problem . It runs amazing . But when it sets over night . When I start it . I have to crank and crank and crank then it will putter and die. Then I crank and crank and it will putter a little longer . Then I crank and crank and it will putter longer . Then I crank and crank and it will finally start . Running rough . Then it slowly smooths out . And then runs amazing . Until I let it set for a couple hours . Then I have to do it all over again . I don't know what else it could be .

[Spinnetti]

hmm. I would have guessed fuel pressure regulator, but apparently that's not it. Dunno.

[ninethree2cc]

Hi, does fuel drain from the feed line on the rail after you have let the car sit? I'm wondering if your rail is draining somehow. I'd let it cool/sit. Carefully persuade the fuel feed line off of the rail. Be ready to soak up fuel with a rag.

[A6sport]

Coolant temp sensor?

[mizzenmast]

Or a break in the fuel line along the way? My hoses to the rail were pretty cracked and am replacing them.

[Saddrs7]

It sounds like you're dealing with a fuel delivery issue, likely tied to pressure retention after the car sits. Since you’ve already replaced the fuel pump, filter, injectors, and regulator, the next step would be to check for fuel pressure leaks or a faulty check valve in the pump. If the system is losing pressure overnight, it would explain the hard starting and rough idle when you first crank it up, as the fuel pressure has to build up again.

[Saddrs7]

Also, consider testing the injectors for leaks and checking the coolant temperature sensor for proper readings during cold starts.