924Board.org

James999 · Joined: 22 May 2008 Posts: 6 Location: South Africa

Hi all, new user here

my 78 924 runs just fine on nice highway runs and in town when there isn't traffic. but as soon as i get stuck in stop start traffic then the car starts giving problems.

the fuel pump gradually starts whining more and more, and then when the traffic does clear up the engine rev's freely up to a point and then the engine runs roughly, as if it is being starved of fuel. but after half a minute of driving at a decent speed then the problem starts going away again. if the traffic persists then the engine begins to stutter and eventually dies. following this people in fiat UNO's drive past laughing as i'm stuck pushing the car to the side. but back to the problem. the car does not start after that happens and i can't hear the injectors spraying when i lift the Air flow sensor manually. if the car is allowed to cool down for a while then it starts again perfectly and runs till i get stuck in traffic again.

any help would be greatly appreciated....
_________________
On the back of my Beetle i need a sticker saying "My other car is a Porsche!" and the Porsche needs a "My other car is a Beetle!" sticker.

Ozzie · Posted: Thu May 22, 2008 4:12 pm Post subject:

sounds like you need a new fuel pump.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

James999 · Joined: 22 May 2008 Posts: 6 Location: South Africa

but wouldn't that problem be a general problem and not just a stuck in traffic problem? the pump sounds fine until you hit the stop start traffic.
_________________
On the back of my Beetle i need a sticker saying "My other car is a Porsche!" and the Porsche needs a "My other car is a Beetle!" sticker.

924er · Posted: Thu May 22, 2008 5:35 pm Post subject:

when your car is stuck in traffic it consumes more gas, and temp rise when the car stops are goes.
_________________
80' Porsche 924 NA - Slower then a S L O W
86' Porsche 951- New toy

Ozzie · Posted: Thu May 22, 2008 5:40 pm Post subject:

On the early models IIRC they only had one fuel pump.
Check the hose to the pump is not soft and kinked and you could also pull the fuel pickup and check for blockages.

Otherwise I still think its the fuel pump not meeting demand.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

James999 · Joined: 22 May 2008 Posts: 6 Location: South Africa

So should i think about converting to run two fuel pumps in parallel, like on the merc's? but once the car has died then the pump still whines and even lifting the air flow sensor doesn't spray the injectors. which makes me wonder if its possibly pumping against a closed line and hence the whine. is it a possible problem with my fuel distributor?

But I will go get a new fuel pump, just in case! thank you
_________________
On the back of my Beetle i need a sticker saying "My other car is a Porsche!" and the Porsche needs a "My other car is a Beetle!" sticker.

Smoothie · Posted: Thu May 22, 2008 9:27 pm Post subject:

Yes, sounds like a fuel pump problem and resulting weak/inconsistent system pressure. -And I'd be willing to guess that the engine is hotter and compounding the problem when in the slower moving stop and go situations. (Make sure the cooling system is good, rad fan/s kicking in, etc., but think the primary problem is with fuel delivery.)
Wasn't the in-tank pump added due to temperature-induced problems? -I'm having a vague recollection of reading that somewhere..
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox