[KesslerR]

Well, I need more help. The engine still cranks for several seconds before slowly increasing the cranking rpm until its at idle.



I had the injectors rebuilt at RC Fuel Injection. One was dripping, one was fair, and two were good. They all were returned excellent and the injectiors were all within a 20th of a percent.

I pumped 15 gallons of gas with injector cleaner added through the system to the end of the feed hose at the fuel rail connection hoping to clean any other varnish etc left from 3 years of mostly sitting. i didn't put that gas back in the 968.



When it still didn't start right up I put a pressure gauge on the outlet provided in the fuel rail. Here is what I see.



Within 1 to 2 seconds I have 60 psi while cranking.

It runs at 55 psi and holds steady either at idle or running the RPM up and down. OK per the spec book.



Shut the engine off and the pressure starts falling right away. Its down to 10 to 15 psi after about 10 seconds and then seems to very slowly fall to zero in 8 to 10 minutes. Spec book says I should have 29 psi after 20 minutes.



After setting 5 minutes the engine usually fires in a second or two. After 10 minutes it may catch after a couple of seconds, but usually dies and then cranks for several seconds before idling.

More than 15 minutes and hot or cold it cranks for 8 to 10 seconds.



Is it the fuel regulator or the check valve at the fuel pump.Can I do the cheap one first? Or something else I am to stupid to know about.

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[banditsc]

You are in need of a new check valve, it's a quick and cheap fix..

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[DaveN]

+1, run with it, you almost never get a cheap and quick fix <img src="/forum/images/smilies/968/smile.png" class="smilie" alt="" />

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[KesslerR]

Thanks for the help. The local Porsche dealer could only get one from Germany, but Pelican Parts had one in stock and its on its way.

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[DaveN]

I am going to replace this valve myself but can't decide whick one it is; who knew there were all those valves back there!



944 608 951 01 the culprit?

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[KesslerR]

You have the right number for the check valve in the end of the fuel pump if no hoist is available, its not hard to change with the right rear wheel off. Good time to change the fuel filter.

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[DaveN]

Sounds good. The car is going up on blocks for winter cleaning and upgrading so access should be OK; my knuckles are doing the happy dance.

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