Fuel injection / filter / fuel to engin

[PeterCapria]

I have a 1980 fiat spider 2000
I have changed the fuel pump, fuel filter , and the pressure regulator
The car will run great for a while and then start to loose power and buck like its not getting fuel until it will eventual stall
If I let it sit or change the fuel filter out even thought it is clean the car will run great again for a while and then repeat the problem all over again does anybody have any suggestions ????

[18Fiatsandcounting]

One possibility is that you're building up a vacuum in the fuel tank as the engine runs for a while, and eventually the fuel pump can't overcome this vacuum and it dies. Try doing a test with one of the vapor lines disconnected from the fuel tank and see if the issue goes away.

-Bryan

[SteinOnkel]

Also, see if opening up the fuel cap slightly (just to break the seal) alleviates this issue. If so, you're either using a non-vented gas cap when you should have a vented one or your vented cap is broken/clogged.

[18Fiatsandcounting]

Also, see if opening up the fuel cap slightly (just to break the seal) alleviates this issue. If so, you're either using a non-vented gas cap when you should have a vented one or your vented cap is broken/clogged.

A much better idea! Now why didn't I think of that...??

-Bryan

[spider2081]

Have you removed the fuel gauge sender from the tank and looked inside??? Is the tank clear of rust and water

[GeorgeT]

Hopefully the filter is not installed backward, they are directional.

[redcars]

Fuel injection cars are supposed to have non vented gas caps. There is a one way valve above the rear axle in the vent line. These valves get plugged up. If you loosen the gas cap and it runs OK then check the valve.

[RRoller123]

That is actually a two-way valve. It holds the entire system at a small above atmospheric pressure level. The FI system receives makeup air ONLY Through the vent at the top of the charcoal canister. If you remove the cap and hold your thumb over the charcoal canister hole while the engine is running, the car will slowly stall out, as vacuum increases in the gas tank. (it does this faster with a full tank, as less air volume in there, more rapid % change in volume). If it doesn't, there is a leak elsewhere in the vent line system.

[PeterCapria]

Thank you for all the reply's
I did the gas cap trick and i know i put the flow of the fuel filter right but the check value and the charcoal canister will be checked next thanks