Cutting out / idle dropping / fuel tank noise after long drive

[pauljsgreen]

Hello again.

2000 Boxster S approx 70k miles. No fault codes stored. Unknown history other than me for the last year or so.

MAF cleaned, throttle body cleaned - no change.

UK summer approaching and the boxster’s getting its startup maintenance planned – not been used all winter.

One problem I had all of last year was that, after maybe a 20 mile drive @ 70mph (motorway / freeway), than enter a city and drive in stop start traffic for another 2 miles or so, the engine revs get very uneven and drop to a point where it almost stalls. Usually it picks up, but if it doesn’t, it stalls and is difficult to start.

All of this is usually accompanied by a fairly loud groan from the fuel tank area. Sometimes, removing the fuel cap, pressing the flap and letting a bunch of air in (or out?) helps the starting if it stalled or smooths out the dropping idle speed.

I have a new fuel filter that I didn’t fit last year, so I will do that shortly, but I was looking for some advice as to what other areas to tackle.

I appreciated you taking the time to look.


Many thanks
Paul

[jmatta]

If I'm not mistaken, the fuel pump resides within the fuel tank itself. This may be a sign of a pump which is starting to fail. Unfortunently, they don't seem to just stop, but act strange intermittently until they die.

I've replaced fuel pumps on some of my other vehicles that acted strangly, but do not have experience with the 986 series.

[Lil bastard]

It's a collapsed hose in the fuel tank stem. Fairly common issue which has had a TSB issued by Porsche, been well discussed here. Do a search and you find lots of reading.

[pauljsgreen]

Originally Posted by Lil bastard

It's a collapsed hose in the fuel tank stem. Fairly common issue which has had a TSB issued by Porsche, been well discussed here. Do a search and you find lots of reading.

many thanks for the rpely.

i've spent hours searching - can i just check - was that a typo "stem" - did you mean "system"?

also, no problem filling with gas / petrol / fuel.... and new air filter

cheers
paul