The one hose I can almost with 100% certainty confirm that is not split is the 180* rubber hose. Since I have not had the actual unit out of the fuel tank I cannot 100% confirm this, I have however reached down inside the tank and felt all around the hose an it feels like there is no splits. My next guess would be possible split or non functioning venturi jets.


Also can someone confirm this:
Based on the video I posted and the tests I conducted, would it be safe to say that I should of been able to see fuel being fed via supply line either through the action of:

• turning the key to "on" and priming the pump
• the act of actually cranking the car
• commanding the fuel pump master relay to activate.

My guess would be that one of those tests should of enabled the fuel to be fed via feed line, correct?

 

If you unplugged the hoses coming out of the tank and toggled the pump, heard humming, and saw no fuel squirting then yeah its something in the tank and IMO fuel should've been shooting out pretty good from one of the hoses.

 

That is my thinking also. I will confirm this tomorrow at my buddies place. I'm going to pull off his supply hose and see if it will expel fuel when car is in the on position.

 

Ok so here's an update:


When I tested my friends 996 turbo the same way, clear hose to supply line and key in on position, it fed fuel instantly.


So I removed the pump system from the tank and from initial inspection of all hoses and connections, and joints I cannot find any splits or damage to any hoses. I'm going to double check tomorrow when the suns out since i'm using a flash light in a low lit garage.


So at this point I guess my next steps are to:
-test the green power wire to see voltage to pump
-test the fuel master relay (possible problem?)
-test the fuel pump out side of tank in gasoline to see operation, if it feeds at all (ill do this in the open out doors for safety)
-re-inspect all lines for cracks and damage
-I will even separate the pump from the basket to test on its own


Any other suggestions you may have would be great!


J

 

The Octopus lol

 

My auto tech buddies always cautioned me about leaving a fuel pump and lines that were submerged under gasoline out and exposed to air.

The plastic is designed to be in gasoline and kept wet with it. Once installed and in service the unit should be left in gasoline except when directly working on it.

Out in air the lines will dry out and shrink and could develop cracks or leaks. Or the cracks/leaks could develop once the unit is installed back in the car/tank.

 

what happened with this did u find ur problem ?

 

Just before you rush off to buy a new pump check the pipework inside the fuel tank.

The two small rubber hoses often split and cause intermittent loss of pressure.

Not easy to see but attached picture shows the problem,

E10 fuel in the UK and Europe affects both rubber hoses and they should be replaced with the correct type of fuel submersible hose.

It is very cheap £4-5GBP per metre and easy to fit.

In the UK it is available from Halfords and other outlets such as NAPA in the USA.

 

my sneaking suspicion is that after years of known split fuel lines on the oem pump, they *may* have been somehow improved over and seem less prone to failure than in years past.

probably only because i havent had one go bad in several years.

 

…on my 100k mile 996 turbo: engine started idling and running rough. Replaced fuel filter-got worse. I ended up replacing the pump and both saddle tank pickups. A rubber elbow inside the swirl pot area had failed (common failure that has been addressed by Porsche replacement part)

Before reconnecting the feed line to the filter and outlet side of the pump, I blew out the line carefully with air from fuel pump side into a mason jar to collect it (at the fuel pump). About 3 or 4 ounces or so of liquid was deposited in the mason jar. Almost half of the liquid was water.
Car runs fabulous now.

Easy fuel siphon trick: attach your long siphon hose (Home Depot clear plastic line) to the end of a 3’ long wire rod with a small band clamp. That way you can “aim” the siphon hose accurately into the lower recesses of the saddle tanks and get about 99% of the gas - and water - out of the tank.