what else should i be doing? - Page 2 - 6SpeedOnline - Porsche Forum and Luxury Car Resource

Mar 25, 2016 | 04:41 PM

#16

Macster

Registered User

Joined: Jun 2009

Posts: 2,190

From: Benton County, AR

Rep Power: 147

Quote:

Originally Posted by BLKMGK

It's possible for a fuel system to lose pressure and cause a prolonged crank at start however this will NOT result in any particular cylinder having additional fuel nor is it caused by cracks in lines external to the tank. Fuel pressure on the high side runs at least 3.8bar and any cracks would spew fuel pretty good! Misfire is going to be injector, spark system, or timing related.

Yes, you are right, which is why I was reluctant to accept a fuel system supply/pressure problem as the root cause.

I'm leaning towards an injector or two as being the problem.

But I have to note the engine didn't misfire this AM nor at lunch. And it has done both of these earlier this week.

When it gets closer to time to change the oil/filter I'm going to try a bottle of Techron to see if that doesn't help. In fact I probably should have tried a 2nd bottle of the stuff the tech gave me and I would but I don't recall the name of the fuel system/engine deposit cleaner. I can remember Techron though.

Mar 27, 2016 | 06:10 AM

#17

Ronny-

Registered User

Joined: Mar 2015

Posts: 215

From: Norway

Rep Power: 32

Quote:

Originally Posted by e8_pack

Any P/N's for the check valves? i had a brake pedal that kept going hard on boost so sure it was one leaking.

I found three check valves, one that has failed on mine and several others
99611013570

And two i've never heard about failing.
Both has 96411095001

And what a ridiculous listprice at 44bucks a piece.
For this..
http://www.autohausaz.com/images/96411095001.jpg