Porsche Enthusiasts Club Forum

Just getting acquainted with my "new" 924. Next to the passenger side suspension tower and connected to the fuel supply, is something that looks suspiciously like a fuel filter. But the fuel filter is next to the fuel tank, so what is it? Pump?

Is it a service replacement part?

Looks like a fuel filter to me. A closer pic would be good.

No sooner said than done:

Yup fuel filter, fairly important to change on mechanical injection as fuel pressure is very important.

But there's one at the back too, or perhaps that is the pump.

The one in the engine bay is the fuel filter, the thing you can see near the tank is the fuel accumulator

Accumulator? AKA pump?

Whereas on the 944, both are at the back?

You should have a pump behind the right hand back wheel, and the accumulator after that, usually above the driveshaft area.

The accumulator is there to try to keep the fuel pressure high after shutting the engine down, to ensure you have fuel pressure when hot starting.. it is basicly a canister, with a diaphragm which is spring loaded, so when the engine is running the spring is compressed, so when you shut down the spring keeps pushing on the diaphragm and maintaining the pressure.

All CIS injection cars have them, as the fuel injectors need pressure to open them, as they are mechanical, not electrical. (effectively each injector is a pressure relief valve, with the fuel distributor altering fuel pressure based on the air pushing the plate open with increasing load and airflow.)

If you do suffer from hot starting issues in the future, one tip is that everyone jumps to replace the expensive accumulator, but 9 times out of 10 it is the fuel pump check valve, which is less than a 10th of the price

that is defo a fuel filter. I think that you should be able to get a replacement at most motor factors.

A good supplier is an outfit called frazerpart. hopefully a google search will turn up an address.

David

try this link. http://www.frazerpart.com/

No connection by the way.....


David

Thanks Jim, Jon, and David. I know that the fuel filter needs to be changed, and I don't have any problem sourcing one. I just couldn't work out what it was because I thought the filter was at the back of the car!