Fuel Injection for your Classic Comes of Age

Photo: Holley
Photo: Holley /

With the easy installation aftermarket fuel injection systems, it is time to take another look at replacing your carburetor. 

I have long been in the category of staying in the era of the car you restore when it comes to upgrading parts. If it was carbureted from the factory you should keep an carb on it. With the new easy fuel injection kits available from several manufacturers now, I have changed my mind on converting to fuel injection.

If you are like me, you have your project car that you wish you could drive more but worry about reliability. The new generation of aftermarket EFI systems take most of the concerns you had about driving your muscle car away. Not only will converting to EFI make your car run better, it will help with mileage as well. After doing the conversion myself, I am sold and recommend it to anyone who drives their carbureted muscle car or truck.

I got my hands of a two different easy fuel injection kits and found very similar results from both, the Holley Terminator EFI kit and the Professional Products Powerjection III. The advantages were instantaneously noticeable with a quicker start and and easier warm up. Installed on a moderately built Ford 460, in cold weather it cranked up like a new car right off the lot. It idled more gently after start up and dropped back to 750 RPM in half the time as my old Holley 4150 with electric choke.

Both systems require installation of a electric fuel pump that can come with the kit depending on how much you want to spend. Being this was my first venture into fuel injection on a classic, I went for the all inclusive kit that included the fuel pump designed to work with both the Powerjection III and the Terminator. It made installation easier with the correct colored wiring to go with the wiring harness from the kit.

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The most challenging part of the installation was the O2 sensors for the exhaust. Both kits come with no weld option instructions, but I went and had bungs welded into my exhaust for more correct and reliable installation. Both kits use similar broad spectrum sensors that are easy to find replacements for at your local auto parts store if one fails.

The O2 sensors are the key to the advantages of the fuel injection switch over. If you do the full installation and put a sensor on both sides of the exhaust (both kits are wired for either one or two sensors) engine trouble diagnosis becomes so much easier. It also allows for better tuning in high performance applications. If you find your engine running rough or have some concerns, plug into the system and find if either bank is running rich or lean. It will help reduce the time trying to find a bad valve or poorly adjusted rocker.

Both systems have the wiring in place to attache to an electronic ignition setup to take full advantage of the upgrades most people have already gone to. Holley even has an additional unit available for those with modern transmissions to help with shifting. With all that you can almost turn your weekend car to a daily driver.

Other than the electric fuel pump and and the O2 sensor the rest of the installation is very straight forward. The appearance of both kits is that of a typical four barrel carburetor so at first glance it does not look as if you defamed a classic. That had been the problem with older conversions, there was the spaghetti wires and odd looking TBI units on a beautifully polished intake manifold. With several finishes and colors to chose from, you can match whatever you have going on under the hood.

One of the advantages of the Powerjection III system was that the electronics are built into the unit’s “fuel bowls” so you don’t have to mount anything else. The Holley system does have a computer you must mount somewhere but it is really not much of an issue in the long run. With some time bundling the wires, the appearance of either system is quite nice actually.

After everything is installed and you are ready to set it up, you will be pleasantly surprised how little there is to do. All you have to do is teach the unit the range of your throttle pedal (a very important step) and off you go. Both systems are learning systems so if you are not looking to tune the system for peak performance you are all set. They take the information form the O2 sensors plus your driving style and will adjust itself for optimal performance.

In my application, a Ford 460, I used it on a Ford Bronco for off roading. With a traditional Holley carb I would occasionally get fuel starvation at odd angles when climbing rough terrain. That has not happened since, and is a great relief. Nothing like the engine stumbling just at the moment you need to accelerate to keep from rolling on your roof. The constant fuel pressure makes sure there is power when you go to the gas.

Profesional Products Powerjection III /

The self adjusting feature is a great advantage for all applications when you change altitude on long trips. Wether heading up the Appalachian mountains or going over Donner pass with you local club, massive altitude changes can really affect your tip and even hurt your engine. With the EFI systems they adjust to the altitude for you, keep your performance and help your fuel mileage at the same time. My Bronco gained almost 11% in mileage just from changing to EFI. Some might have been how I had the carburetor adjusted, but the consistency throughout the range of the throttle is truly amazing.

Here is where the two systems separated for me. I started with the less expensive Powerjection III system from Professional Products (MSRP $1,798) and was very happy with its self adjusting capabilities. When I went to try and plug it into my computer to tune it up I was not able because of no Mac support. From all the reviews I have read, people with Windows based laptops are very pleased with the the tune-ability of the system. For me, the lack of a Mac interface is frustrating as I am not going to buy a new computer just to tune my car.

The Holley Terminator EFI comes with its own control unit that you can plug in and adjust your settings or see your sensor data. For those who like to fiddle with the your settings and make adjustments, you can mount the included display and have easy full time access to everything you need to know. The Holley system is more expensive (MSRP $2,449) but for those who want easier tune-ability it is worth with the difference.

If you are thinking about making the change, there are several more options than the two I tested. They cover a wide variety of horsepower needs and specific applications, so take your time and do the research before you purchase. The technology has advanced to the point the only reason not to switch over is for originality, but if you want to enjoy your classic more and tune on it less the time has come to make the jump to EFI.