Cold start fuel issue?

[Cornishman]

I could do with a little help please.
I have a recently bought csi which starts and runs well when hot, however if I leave it for a week then it sounds like no fuel getting to the engine when i crank it. The electric fuel pimps buzzes continuously and it won't start, leaving it key on for a couple of minutes and she will then fire a few times, after that she starts, runs rough for 30 seconds and then runs like a dream. My experience is mostly with diesels, from that I deduce it is leaking back and needs to prime itself again. Does anyone know if there is a check valve somewhere that could be the issue?
Perhaps by coincidence it had a new fuel lift pump, two filters lne by the pump and one jnder the hood, and all of the hose clips on the fuel system changed recently by the look of them.
Any other advice?

Thanks for any advice.
C

 

[61porsche]

Remove the two extra filters. Make sure you don't have a sediment / rust problem as three filters is unusual. Just one in the engine compartment. It might be helpful to know which FI version?

 

[Cornishman]

Thanks

Thank you. I will get the tank off and give it a clean this winter, also change the filters back to one as suggested.
How do I know which FI system is fitted, I realize that sounds like a stupid question, but I am new to this game.
Thanks
C

 

[bill]

CSis came from the factory with D-Jet, identified by the "log" intake plenum connected to the head with six "C" tubes. Also has an auxiliary air valve ("air slide") under the intake. Previous owners of your coupe may have upgraded with L-jet or something else...would help if you could post a picture.
As for your cold start problem, have you checked the operation of the cold-start valve (screwed into the log in the middle on the left side)? HTH.

 

[Sven]

C -

How do I know which FI system is fitted

Assuming you have the individual "C" shaped intake runners (the logs). The original D-Jet system used a very thin metal fuel tube feeding the injectors (smaller diameter than the rubber tubing). The L-jet system used a much larger diameter fuel rail. Motronic setups may also look like the L-jet (except for the ECU box is different). And some Motronics will use the newer single piece intake manifold. You can also check so see what ECU box is under the rear seat.