996 TT Fuel Problem
 

Does anyone know of a fuel problem that occurs to the 996tt. I was driving on I-95 about 70mph, dropped the gear into 4th.... stepped on the throttle and about 90mph the engine let go... I lost all boost and the rpm went to zero. It seemed like an intake hose let loose, telling the engine to shut down.
Took it to the shop. Put it on the lift..Inspected all hoses and undercarriage...no damage found. Put the computer on, no codes reviled any problems. No catastrophic failures. The engine will start up but will only run for 1-2 sec. narrowed it down to a fuel problem....fuel pump quit-(inop). Changed out fuel pump with new. New pump is working but no pressure is reaching the intake side of the fuel filter located in the back. According to the fuel diagram the are no check valves or adjuncts between the fuel pump and filter.
It appears for some strange reason....we can't get fuel pressure into the engine.
I blame this all on the ETHENOL...the shop had two other cars in with fuel related problems.
Does anyone know????
Thanks Pete

yes...the fuel line inside your tank ruptured....so the pump keeps pumping the fuel back into the tank. It happened twice to me.

search is your friend

yikes. an independent P mech advised me he's seen a hand ful of failed fuel pumps rolling in. ruptured fuel line and failing pumps common on stock fuel systems?

fuel pumps have been a weak spot for Porsche....the fuel lines is a mystery. There is a hypothesis that Ethanol doesn't play well with the polymer used in the fuel lines...although if that were true fuel lines would be failing all over on all European cars (they use less ethanol in Europe). I thought it might be toluene as my lines failed when I was filling up with 100 octane....I called the VP of technology for VP fuels and he said the basic chemistry of pump fuel and VP 100 was the same....so who knows.

I'm actually putting the new pump in as we speak.. Same exact problem!!

Fuel Lines
 

Has anyone contacted Porsche directly for a response to this problem, no recalls?
Has anyone found a good fix to this situation??

Porsche knows. They've at least updated the parts when the EPA heard there was a fuel leak problem. Their response to the govt is that the leak is internal to the tank, and the bad parts have been removed from stock. The new p/n ends with -02.
Porsche pays nothing for those out of warranty.

Well I found a memo from Porsche to EPA because it is a fuel system problem stating that a bit over 8% of the newer 996TT's had pump failures but no release to atmosphere of fuel. The corrective action is a revised part and old parts pulled from shelf.
Huh. I wonder as this is a report on the "newer" 996TT's. I wonder what the failure rate of the old ones are given the longer exposure to ethynol.
Also, 8% were covered by warranty. I wonder if another 20-30% or more were out-of-pocket? Mine is going on it's second replacement pump on a 20k mile car and I'm a little hot about buying a $500+ pump that's known to be a problem. Hopefully the newest incarnation does the trick. Just wish Porsche would pick up the part, I'll eat the tow.

Here's a link to the memo.

http://www.regulations.gov/fdmspubli...ontentType=pdf

Fuel Lines
 

Thanks for the info; I‘m looking at it.

So just installed a brand new stock fuel pump. Did not fix my problem just put a dent $550. So the car still shuts off. It has the Evoms GT700 fuel lines. I don't know what else to check.

Gt700 shutting off
 

what else should one look for?

I would contact EVOMS...

from pump to injectors
 

If your Pump is new and your lines are gt700 then check your fuel filter. Make sure your

getting gas that far and if so, check that fpr. Next the injectors if all is well and still no go.

Time to get drastic, would your hp require you to have an inline pump and or 5bar fpr, if you

don't have these already. However if you do then I would (and I know you're not me) spray

gas in the intake to know for sure that I had a fuel problem and not a computer problem. Just

my .02 I bet you know all this anyways, hope you get it fixed.

On the Gt700 there is only the stock fuel pump, no additional pumps are needed at this level, anything higher it might. What's the best way to check injectors?

thanks for the info. i hope you guys sort out the problem. no fuel in atmosphere but this could be catostrophic if failure occurs at WOT, time to do a search on aftermarket fuel pumps...

Tks for sharing info! :)