Technical Do I even need a fuel filter?

[Richenrygarcia]

I recently relocated my fuel filter from the engine compartment, to the front compartment, right after the tank, as recommended on the Italian Fiat 500 forums. It turns out this set up did not work well for me, as the engine would starve of fuel after five minutes of running in this setup. When I removed the filter, the engine ran just fine.

So after some thinking, I wonder whether I really have a need to mount an external fuel filter? The carburetor already has a screen which takes care of filtering the fuel headed to the engine.

The external filter would only serve to filter impurities prior to the filter. In this case, I wonder if the "juice is worth the squeeze" or is it just another unnecessary connection.

Thank you.

 

[Bigvtwin996]

......So after some thinking, I wonder whether I really have a need to mount an external fuel filter? The carburetor already has a screen which takes care of filtering the fuel headed to the engine. .....

Did Fiat feel the need to fit a 4th Filer "No"
Do Fiat know more about cars than the general public "Yes"
Is Fuel filtered at the pump and cleaner than in the 50s/60s "Yes"

If your fuel tank and lines are dirty or corroded then it would be better to clean them and replace the rubber fuel pipes with Ethanol resistant ones...


I don't believe there is a need for an extra filter, they are usually of dubious quality.. the main reason I see for them is to see if fuel is flowing, clear pipe to the carb would be better but this hardens and would need replacing when it does, so if you feel the need to see fuel. (I don't believe we feel this need with modern EFI cars)


Just my opinion.

 

[Richenrygarcia]

If your fuel tank and lines are dirty or corroded then it would be better to clean them and replace the rubber fuel pipes with Ethanol resistant ones...


Just my opinion.

Thanks for the reply. Funny you mention it, but I replaced the ancient clear tubing with modern black, rubber fuel hose this week. I was in the process of replacing the carpet so I took the opportunity change out the hose. The new hose looks far more robust than the old Cavis tubing.

 

[Bigvtwin996]

Thanks for the reply. Funny you mention it, but I replaced the ancient clear tubing with modern black, rubber fuel hose this week. I was in the process of replacing the carpet so I took the opportunity change out the hose. The new hose looks far more robust than the old Cavis tubing.

sorry if I sound harsh.. just I don't believe there are too many things we need to do to improve these cars....
they and other classics ran perfectly well when they were new...

There are a few things that can be done to improve classics using technology that wasn't available when they were built.

 

[phoenix1]

I had a similar problem as I had the in tank filter , a filter in the engine bay and a non return valve .My 500 L used to cut out after about 10 miles .So I eventualy took off the extre filter and non return problem solved. ( after much searching ) I had already fitted a new pump so I assume they are marginal on pressure .

 

[the hobbler]

I have discovered that the standard 500 fuel pump does not have as much suck as is does puff! I had a one-way check-valve between the pump and the carb---engine ran fine. For a variety of reasons I decided to move the valve to just outside the fuel tank. If I drove the car gently, no problem--but if I drove it 'enthusiastically' it would start to hesitate and hold back after about 5 minutes of running. This started happening 1 day before I was due to trailer my car to the 'Abarth' day at Rockingham--slight panic! I removed the valve, replaced it with modern fuel pipe----problem solved; the engine now runs as strong as ever. The original system has a minimum of 2 filters in it as standard---if you fit a bigger carb (in my case a Dellorto FZD) you end up with 3 filters. If they don't keep your fuel clean, you have a fairly serious tank problem.