Hi all, I just recently purchased an 08 957tt with excellent service history. It has been amazing so far! I do have an issue where when the car has sat for a long time, hours, it takes a little longer to start. I have noticed that if I put the key in and turn the car on but not the engine, and wait for 30 seconds, it starts perfectly fine. I am thinking it's loosing fuel pressure but not sure how to verify what part needs replacement. Anyone have ideas on how I can confirm or if you know based on this information? Thanks so much!

 

When you open the driver's door, do you hear the fuel pump prime? Do the interior light come on?

It will prime the first time you open the door but won't do it subsequent times for another 10 or 15 minutes.

 

Yes to both

 

When it slow starts, is the tach needle jumping regularly as the engine turns over or only moving sometimes and sitting dead at 0 with no movement other times.

 

The tach only moves sometimes. I just watched it and it sat at zero for the first 2 revolutions, then jumped to maybe 50rpm for a revolution or 2, then started with fully functioning tac. Although the car was cold, I did drive it about 5-6 hours ago. First start of the day may take 10 or more revolutions if I don't give the car 30 seconds upon inserting key.

 

I would replace your crankshaft position sensor and see if that doesn't solve it for you. The tach needle not moving regularly means it's not.always seeing the engine revolutions and doesn't know when to fire the spark and injectors.

 

Great, thanks so much!

 

I ended up ordering a scan tool to clear the service now message. It read a lot more codes than my other tool. I'm getting "P1023 Fuel high pressure too low during starting" and "P2181 Cooling system performance" (probably unrelated). I'm guessing the P1023 is my starting problem and I'm guessing its the high pressure pump. I read pressure at the rail with my new tool. It was steadily dropping with the car off. About 1 mbar/sec. Not sure if this is normal, guessing not. Anyone want to chime in on any other possibilities before I pull the trigger? Thanks!

 

Bump, Gulp, that HPFP is pricey! The car runs great so I definitely don't want to replace unnecessary parts (especially with inferior ones, as I cannot afford $3,500 for an OEM HPFP). Is there anything else that could be causing this P1023 code and/or excessive cranking? I would change the CPS but I would think I would see a code for it. Thanks for any help y'all can provide!

 

Does the car ever fire right up and only does the long crank occasionally? If yes, see if the tach needle is behaving differently during the two different scenarios.

 

It is similar in both cases. Just ones take longer to fire up.

 

Have you tried double priming the system to see if it makes a difference?

Open drivers side front door, close door. Wait 15 minutes, oped door again and try and start the car.

If it fires up faster this way it means you're losing fuel pressure from the system either from a faulty check valve or down into the cylinders from a leaking injector(s).

You can't open the door again sooner than 15 minutes as there's a countdown timer that prevents the pump from cycling again within a certain time window. I think 15 minutes is safe but it could be longer than that. If you don't hear the pump prime on the 2ns opening after the 15 minute waiting period, start again, but with 20 minutes between consecutive door cycles and listen for the pump that 2nd time again.