El Camino EFI Conversion - Fuel Injection

Hopefully you anti-fuel-injection folks have not skipped over this story due to its nature-fuel injection! Having been around the hobby for a bit, we've noticed the great divide between the fuel-injected crowd and the carbureted crowd. While both sides have learned to coexist, there are still many arguments about which method of fuel distribution is best.

Carburetors are typically easier to install and cheaper to purchase, and they're required on restored vehicles that rolled from the assembly line with one. Carburetor technology continues to flourish on street and racing applications. However, in order to keep your ride performing at its best, carburetors require frequent maintenance, as well as jet and air bleed swaps due to alterations in altitude and ever-changing weather conditions, never mind frequent choke adjustments. Additionally, carburetors usually lay low on the "wow" index.

Pictured here is the Powerjection I EFI system 750-cfm billet polished throttle body accompanied by the Engine Management System (EMS), wiring harness, wideband oxygen sensor kit and module, port-styled injectors, and various sensors (the fuel delivery components are not shown). A quick glance and even the savviest enthusiast would be fooled.

Pictured here is the Powerjection I EFI system 750-cfm billet polished throttle body accom

Electronic fuel-injection systems are more on the expensive side, but include many additional benefits compared to conventional carburetion. EFI provides a broader powerband, as well as more consistent cylinder-to-cylinder fuel distribution. With various sensors giving feedback to the electronic control module, EFI can adapt instantaneously to changes in weather conditions as well as altitude. With EFI, you don't have to pump the gas pedal to get your hot rod started, and choke adjustments aren't necessary even in the coldest climates. EFI generally ranks high in the "wow" department.

We've all seen our fair share of cool stuff, and Professional Products' new Powerjection I EFI Fuel System is now on that list. How about keeping your current carbureted-style intake manifold as well as the existing ignition system while modernizing your fuel distribution method to EFI? It even looks like a carburetor for you traditionalists. Professional Products has made it easy to install. The Powerjection EFI contains two key features: a returnless fuel system suitable for engines under 500 hp, and a self-learning Engine Management System (EMS). While it is not necessary to program the EMS via a laptop computer, that feature is available for those who choose to do so.

The Powerjection system is unique because it can be bolted in place of your standard 4150-style carburetor. Its dimensions are similar to a double-pumper carburetor, and its fuel inlet kit, linkages, and air cleaner size and location are identical to the original. The Powerjection unit also allows you to retain the vintage look of a carburetor with the modern conveniences of fuel injection.

To test the Powerjection unit, we wanted a mild-mannered Chevy with excellent driveability, decent horsepower, and a tried-and-true Chevy 350 engine. After a quick phone call to our friends at Crazy Horse Racing in South Amboy, New Jersey, we were acquainted with Lenny Knell of Staten Island, New York. Lenny was a little hesitant at first, being an old-school Chevy guy (anti-fuel injection), but we talked him into letting us transform his '87 El Camino into EFI-promising him positive results, as well as less maintenance.

Let's get started with the install.

Before beginning any work, we decided to strap the Camino down to Crazy Horse's Dynojet chassis dyno for some before numbers. After a few stabs, we were less than satisfied; the 350 was sputtering through the rpm range and emitting black smoke from the exhaust (running rich). Horsepower numbers checked in at an extremely low 188. We believe this was due to clogged air bleeds in the carburetor, so rather than waste another minute, we began to install the Powerjection EFI system knowing it would alleviate these problems.
Before beginning any work, we decided to strap the Camino down to Crazy Horse's Dynojet ch
Installing the Powerjection unit is Crazy Horse Technician Glen Knell, who happens to be Lenny's son. Glen began on the underbelly by installing the inline electronic fuel pump and prefilter (which is a standard GM-style GF481).
Installing the Powerjection unit is Crazy Horse Technician Glen Knell, who happens to be L
Luckily, the El Camino already had 6 AN steel braided fuel line installed, which is required to handle the higher fuel pressure produced in a fuel-injected system. Since this is a returnless fuel system (one line from the fuel tank only), the EMS will pulse the pump to achieve the desired fuel pressure depending on the conditions set. Glen found a suitable location with easy access to mount the filter and the pump inline on the framerail.
Luckily, the El Camino already had 6 AN steel braided fuel line installed, which is requir

The next order of business was to remove the carburetor. Glen took out the throttle linkage, throttle return springs, vacuum lines, fuel supply line, and four carburetor-to-intake flange fasteners.
The next order of business was to remove the carburetor. Glen took out the throttle linkag
Once all was clear, the carburetor was removed from atop the 350.
A side-by-side comparison shows the similarities between the units. The Powerjection unit is much slimmer sans the vacuum secondary diaphragm, choke horn and plate, and electronic choke stat.
A side-by-side comparison shows the similarities between the units. The Powerjection unit

Housed within the so-called bowls of the Powerjection unit are the four port-style fuel injectors, idle air control, and fuel pressure sensor. A throttle position sensor (TPS) sits on the outer part of the unit, working off the throttle shaft to give the EMS feedback about the throttle plates' position.
Housed within the so-called bowls of the Powerjection unit are the four port-style fuel in
Once the 750-cfm Powerjection throttle body was set atop the intake manifold, Glen reconnected all the fasteners and throttle cable connections. It was then time to locate a future home for the coolant temperature sensor (CTS).
Once the 750-cfm Powerjection throttle body was set atop the intake manifold, Glen reconne
The CTS allows the EMS to determine engine coolant temperature in order to deliver the precise amount of fuel, whether it's cold, aiding in start-up, or adding fuel to an extremely hot engine to aid in cooling. A suitable location was found near the distributor on the Edelbrock Performance RPM intake manifold.
The CTS allows the EMS to determine engine coolant temperature in order to deliver the pre

Since we're using an electric fuel pump, the mechanical unit needs to be removed from the engine block. The El Camino also employed this inline filter, which we'll reuse, as the instructions indicate a pre- and post-pump filter should be used.
Since we're using an electric fuel pump, the mechanical unit needs to be removed from the
Once Glen removed the mechanical fuel pump, he used this block-off plate with a thin coat of silicone in its place.
Once Glen removed the mechanical fuel pump, he used this block-off plate with a thin coat
The EMS must be placed in a cool, dry area in the cockpit. Since the El Camino came from the factory with computer controls, we figured we would mount the unit in the passenger-side kick panel. A wideband oxygen sensor module also needs to be mounted in a similar manner to interpret the signal going to the EMS to aid in proper fuel mixture.
The EMS must be placed in a cool, dry area in the cockpit. Since the El Camino came from t

In order to help feed the wiring harness to the outside of the vehicle, Glen utilized an old oil dipstick to poke through the firewall grommet; once the harness was taped to the end, it was gently pulled through to the engine compartment.
In order to help feed the wiring harness to the outside of the vehicle, Glen utilized an o
Back under the Camino, Glen drilled a hole into the exhaust in order to weld in an oxygen sensor bung (provided with the kit). The instructions advise positioning the sensor away from the bottom of the exhaust to deter any contaminants from entering the sensor.
Back under the Camino, Glen drilled a hole into the exhaust in order to weld in an oxygen
Once the bung was secure, Glen installed the wideband O2 sensor and harness.

Coming down the home stretch, Glen found a suitable location on the passenger-side wheelhousing to mount the manifold absolute pressure sensor (MAP). A single bar sensor is used on naturally aspirated versions, although a two or three bar is available for boosted applications. It is advisable to keep the sensor close to the engine, allowing for a shorter length of vacuum tubing to be used.
Coming down the home stretch, Glen found a suitable location on the passenger-side wheelho
Finally, Glen went over all the fasteners, electrical connections, and fuel fittings to ensure they were properly connected before reawakening the Bow Tie. While most are afraid of performing any kind of wiring job, the Powerjection instructions are very detailed, making life easy.
Finally, Glen went over all the fasteners, electrical connections, and fuel fittings to en
Before starting the Camino, Chris Winter, owner of Crazy Horse, decided to attach the laptop to the computer system via a USB cable (not included) to be sure all the EMS parameters were correct and the sensors were functioning as they should. Chris indicated that the software was easily installed and operating. The Powerjection unit comes programmed to start and run a 350 containing a mild camshaft; a complete set of instructions is available to load the EMS for additional applications. Once the start-up program is loaded, the EMS does the rest-usually in a half hour's worth of drive time.
Before starting the Camino, Chris Winter, owner of Crazy Horse, decided to attach the lapt

The "before" graph shows our not-so-successful carbureted dyno results. The mild 350 was breaking up due to carburetor malfunction, putting out only 187.9 hp to the rear wheels.
The "before" graph shows our not-so-successful carbureted dyno results. The mild 350 was b
After installing the Powerjection I System, our power and torque curve smoothed out immensely, providing the El Camino with a far more respectable 238.3 hp and 306.4 lb-ft of torque. Beyond drivetrain loss, that puts the 350 in the 280-300hp range at the flywheel, which is not bad for a daily driver.
After installing the Powerjection I System, our power and torque curve smoothed out immens
With some basic automotive knowledge, a typical Powerjection I install can be completed within 1-2 days. Driveability improved greatly compared to the carburetor that previously fueled the El Camino, and throttle response was unbelievably crisp. Start-ups are now a snap without having to worry about choke adjustments, and never mind the much-improved image under the hood. This system as tested will cost you around $2,750 with the polished billet throttle body. One can opt for the die-cast polished unit for around $2,300 and the die-cast natural finish for $2,200.
With some basic automotive knowledge, a typical Powerjection I install can be completed wi