996 won't fire after fueling

[dbmies]

I have a 2000 996 with 107k miles

I had the AOS replaced about 20k miles ago.  I replaced my crank position sensor about 5k miles ago to prevent hot start issues.

For the third time in about 3 months (I don't drive every day)  my 996 wouldn't fire after filling up with fuel. I had been having issues with gas station pump nozzles shutting off prematurely - in California where we have the vapor recovery nozzles that aren't good for topping off the fuel.  But the only way I could get my tank close to full was to fill it very slowly.

The first time I had the starting trouble after fueling, the car started up normally, but as soon as I pulled out onto the street and stopped at a traffic light the engine died - as if the fuel pump had stopped. When I tried to restart, the engine cranked but with no signs of fire.  I pushed it back into the gas station and after 15 minutes with tow truck on the way I tried one more time - with the pedal floored - and it started after about 5 seconds of cranking.  

The second time about a month later, I was far from home and it wouldn't start at all after refueling (again after topping off).  I found something on the internet that said you can over-fill the tank and get fuel in/near the charcoal canister - causing some sort of safety shut-off to protect the canister from damage.  So I tried to siphon some gas out but my siphon tube went in the filler pipe at least 36 inches without getting wet I figured over-filling was the issue. Eventually I got frustrated, cranked with wide open throttle and after about 5 seconds it started.

I replaced the fuel line vent valve to fix the premature nozzle shut-off hoping it would fix both issues.  After doing so I drove to the station and filled up with fuel - no premature shut-off of the nozzle this time.  But again the car wouldn't start.  Without hesitation this time I cranked with wide open throttle and it started after about 5 seconds.

I found this link on the internet among others saying the cool fuel can prevent a worn piston from building pressure - http://www.fixya.com/cars/t3860084-after_fuel_fill_cap_removal_2003_996

Think my next trial will be to replace the fuel pump unless anyone has a better idea?  Should I test the pump pressure first before replacing?

It isn't throwing any fault codes - I'm getting some occasional idle surge with the engine is hot - just started recently.

Last I checked (after the first incident) nothing jumped out at me on the Durametric.

All advice and DIY links appreciated. Thx

Edited March 14, 2017 by dbmies
clarification

[Paul Grainger]

Check your fuel pump relay. I had similar issues which ended up -eventually - with being towed back home. Ended up being the fuel pump relay. My dealer said 'mmmm. They tend to fail after about 10 years. We sell a lot of them......' 

[Hilux2400]

I carry a few spare relays around with me.  The fuel pump relay is in the main panel near the fuses.

There's a post somewhere showing the relays and their functions.  I've been searching but can't find it.  I think it's under Relay Location posted by Richard Hamilton May 2012.

Edited March 14, 2017 by Hilux2400
Got relay location wrong

[dbmies]

Thanks - I carry spare relays in the car but why would it only occur after refueling?

[Loren]

Check you fuel pump output.

On a 17 year old car it is likely the fuel pump is worn and leaking back pressure.

[dbmies]

Replaced the fuel pump. Went straight to the station and filled up with 15 gallons. Started up no problem. Think that fixed it. Thanks all.