Originally posted by Don Meyer
One item I have not seen posted is on the different types of fuel injection units:
1.types available
2. adv/disadv of each type including costs
3. aftermarket vs. factory
4.factory or aftermarket wiring harness
Don
Well Don,

This isn’t really a reply to your questions... but if you’ll indulge me, I just want to say a few things about the “basic” differences between my geezer carburetor setup and the computer driven electronic fuel injection systems.

Some folks around here know that I’ve been lusting for one of those Hilborn EFI’s for some time, so I’ve been trying to figure out all of the ancillary work involved in getting an EFI system to work properly. And from what I’ve learned so far, it’s a whole lot more difficult to convert a carburetor system to EFI than to build your project from the beginning with an EFI system in mind.

What I like about EFI (the Hilborn setup is icing on the cake) is that you can accurately fine-tune the system to provide the optimum air-fuel mixture for power (or efficiency) across the entire power curve of an engine. The down side appears to be “that it ain’t simple” for the average person to tune (or program) the system.

But before you even think about the tuning (or computer programming), you’ve got to have the right electrical and fuel plumbing system. There is a computer module and an array of sensors: O2 sensor to read the exhaust and determine if the air-fuel mix is too rich or lean, a manifold pressure sensor, an air inlet temperature sensor, and an engine coolant temperature sensor. And since the EFI system also controls the ignition timing, your ignition system is going to have to be compatible with computer controlled EFI too (no vacuum or mechanical advance).

What else is unique for the EFI system? You’ve got to have high-pressure type supply and return fuel lines (50 psi vs. 5 psi for carburetors), a special fuel tank with a sump (or modify your existing tank), a surge tank to help prevent air from being sucked into the fuel line, a fuel pressure regulator, special fuel pump, and special fuel filter. And also, your electrical system and wiring need to be in very good shape... static or noise in your electrical system will mess with the computer module!

I’m awfully intrigued by the EFI systems, but my ole geezer head has got some more learning to do. Maybe one of the young fellows can help to convince me that it's more simple than it looks

Dan J