Fuel
Asked by GuruDX2N4 Aug 21, 2017 at 12:44 PM about the 1984 Porsche 944 STD Hatchback
Question type: Maintenance & Repair
My porsche has a fuel line coming out of the tank
then it goes directly into the fuel pump then a filter
after the pump. This makes no sense to me is it
possible to put a filter in before the pump ???
2 Answers
Hornet_2497 answered 6 years ago
That sounds correct for the older carbureted cars. Some even had a fuel filter that was threaded into the carburetor to block any debris like a failed fuel pump diaphragm. It might not hurt to add another filter on the fuel line going into the pump if you are concerned. But doing so could lead to fuel vapor lock on hot days. Here's what could happen. If the added filter starts to clog and causes a vacuum, gasoline under vacuum will boil up bubbles and the pump won't pump air or suck gasoline. Try it and see but if the engine gets finicky at low speeds on hot days, you will want to remove that added filter. (Gasoline under pressure will not boil/vapor lock at high temperatures.)