Never read about having to wait to pressurize the fuel system on the 09. I know that other DFI systems remain underpressure but not sure if for some reason the Porsche DFI does not. For example my Mercury Verado outboard engines on my boat remain under pressure because when I change the water/feual filter I have to push a button to relieve the pressure.

 

With 1000 miles on my '09 C2S, I notice that the engine surges for the first 30 seconds when cold. After that it smooths out just fine, but no other Porsche I ever owned had that surging when first started. I"ll try the starting procedure mentioned in the earlier post to see if it helps.

 

I don't know. Just an observation from the points in the thread - 997.2 DFI AND BMW 335i DFI fuel pump issues.

 

What do you mean by surging? A cold engine idles fast, say 1000RPM perhaps a bit higher, when it starts and then should slow to 750RPM - that's normal.

 

No it's not from the 997.2 manual. My car has a VAG 2.0T FSI direct injection engine, and alot of the other owner's report cranking issues when they open the door and sit down on the seat and turn the key right away. I dont know how the 997.2 is but the 2.0T FSI primes the fuel pump when the driver's door is opened, and my car has started almost everytime by holding the key on the "ON" position for 2-3 seconds before turning it over.

Doesn't hurt to try, let me know how that goes...

 

I know for sure the Cayenne is just like Audi/VW has been for years where as the pump runs to prime the LOW pressure system, when you open the door (everyone has forgotten to remove the fp relay an opened the door with the intake manifold out, fuel sprayed over to the next bay) so in those vehicles you should not need to hesitate to start the vehicle. Sports cars on the other hand I'm pretty sure both EFI and DFI cars do not run the pump when the door is opened but rather when. Either way all but one DFI starting problems I've seen have been high pressure pump issues, and leaving the key at run before going to start should not be necessary. If your new Porsche seems to take long to fire, take it to the dealer.

mdrums: Myself and most of the folks in ATL suspect that the old gt/turbo engine will be replace with one based on the current carrera bottom end, at that point both would get DFI. The new carrera motor seems to be built strong like the ol air cooled motors, where as the 996/997 carrera motors were rubish. Don't for get it wasn't long ago all 911 had the same basic motor.

Turbos will get PDK, but in my opinion if the gt2/3 ever lose their clutch pedals, it will be proof even they aren't safe from "The Man".

 

996/997 motors "rubbish"

 

Yep, like adias says it's normal! Almost all cars idle at a higher RPM when cold. My M3 fluctuated idle like no other when it was cold.

 

rubbish may be harsh, but the two piece crank/block set up and intermediate shaft design, is not the finest example of Porsche engineering. They got it right by 05-06ish but its hard to forget 3 Boxsters in the shop getting their second motor at the same time...

 

My '09S with 3000 miles dies when starting immediately after I let go of the ignition key every 3rd or 4th time only when then engine is cold. I suspect it may have to do with DFI system pressurization. Also, I have noted on several occasions surging immediately after driving off in cold car in first gear.

 

nope.

 

You should have that checked and afterwards please report back.

 

there are two pump for the engne fuel the first is low pressure like a non DFI motor and the high pressure pump (120 PSI) the high presure pump work only when the motor is on
the high pressure pump is just on the came shaft bolt

when you turn on your engine it,s only residual pressure in the high pressure ramp

sorry for my english,because i am french

 

You are referring to the pump on the left back of the engine as in the image below:



What do you know about that part? does the engine need to be dropped to replace that pump?

 

yes it is the high pressure pump,yes i think don't need to drop the engine to replace this pump but you ned to drop exaust

this pump create a 40 to 120 psi pressure in the too ramp to the injectors
this have a maximal debit of 180litre per hours a 120 PSI
this pump have a regulator built in and a thermal compenssator
this pump have high pressure bypass security

there a two pressure indicator built on each ramp by cylinder bank

i'am so sorry for my english,i can explain more in fench,i wish you undertand what i write
i' have a lot of more info about this engine