TonyK
True Classic
The stock Abarth Fiat 500 platform uses a fuel pump that is located in the fuel tank. Gone are the days of having a fuel rail that has a pressure regulator connected to the rail and makes reference to the plenum pressure or vacuum. The ECU calculates the injector open duration based on MAP values. In simple terms, if the plenum is at 26 PSI boost and the fuel pressure is 36 psi then the Delta value is only 10 PSI. To get the required amount of fuel the injector must stay open longer. When the engine is operating under vacuum -10 PSI the Delta value is now 46 PSI and the duration of when the injector is open must be shorter. In the build that I have done I used a Bosch type external fuel pump. The problems with these pumps is that the rotor in the pump appears to be made of soft material and the pump wears out the slots in the rotor and fuel flow is starved. The issue I have now is trying to find a good pump. What I am saying is when I went to Car Quest they offered a Bosch pump for $300 when I asked is it a Bosch Pump or a Chinese knock off that will fail, they could not answer the question. Knock off pumps seem to last only about 3000 miles and present sudden drop in power followed by a surge and it repeats it's self. Like riding a bucking Bronco. The Abarth engine requires 59 PSI at the rail. The current pump in the car has an output of 72 PSI and a fuel regulator is used and set to 59 PSI. If anyone knows of a good quality pump please let me know. The knock off Bosch just isn't cutting it.
I have attached a few pictures of the fuel pump location on the Abarth X1/9.
Comments most welcome.
TonyK.
Grimsby Ontario Canada.
I have attached a few pictures of the fuel pump location on the Abarth X1/9.
Comments most welcome.
TonyK.
Grimsby Ontario Canada.