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High-Tech Jeep
Edelbrock EFI & Header Install: Modernizing a Balky Old Wrangler with Edelbrock Headers and Electronic Fuel Injection
story & photos by Steve Temple
Anybody who’s ever chugged up a steep slope knows the potential problems with a carbureted engine. Just ask Yogi Aguiar, shop manager of Adventure Jeeps. About four years ago he bought a ’76 Wrangler CJ-5 with a 304ci V8. Even though it ran pretty well at the time, he began thrashing it on some pretty demanding trails at Moab, Camelback, and Gorman, among other areas. After awhile the engine began to run a bit smoggy, and he had trouble with it stumbling when he would shift into reverse to prevent from flipping backward on a sharp incline. And, like most off-road adventurers, he wanted some more power in addition to better driveability.
To bring his old warhorse up to date, Aguiar decided to first rebuild the engine from top to bottom. He extrude-honed the heads, and also installed a new valvetrain and set of pistons. With a freshened block and stronger internals, Aguiar was ready to start pulling more power out of it.
That’s when Edelbrock joined the performance party, supplying a set of exhaust headers and a Pro-Flo Multi-Point Electronic Fuel Injection system. The weight savings alone are an advantage, as the stock cast-iron components feel like sea anchors in comparison to Edelbrock’s finely machined aluminum pieces, which also look a whole lot more sophisticated to boot.
Edelbrock headers
The exhaust headers feature individual runners that tune the exhaust pulses for more horsepower and torque. As for the intake, it’s similar in configuration to an Edelbrock Victor Jr. single-plane manifold that’s found on countless numbers of hot rods and muscle cars, but designed specifically for EFI applications. It not only has two more bores in the Weber air valve than found in the stock throttle body, but also individual runners for a ram-air effect.
An added bonus of the EFI system is the elimination of fuel sloshing that’s sometimes a problem with a carbureted engine. This system is ideal for Jeep owners who will want the all-weather, all-altitude performance of multi-point fuel injection. Edelbrock’s EFI is not affected by extreme inclines or angles, whether you’re rock crawling or storming sand dunes. You’ll get great throttle response throughout the rpm range, along with better fuel economy.
Edelbrock has an EFI available for a number of engine sizes and model years: 1967-69 AMC for 343 and 390, c.i.d. engines, and 1970-91 AMC/Jeep V8 for 304, 360, 390, 401 c.i.d. engines. It includes an assembled induction module (aluminum manifold, 4V throttle body, fuel rails and injectors), ECM with interchangeable chips, wiring harness, all required sensors, Calibration Module, billet distributor and fuel pump. And this EFI relies on a speed/density system for control over fuel and spark without a laptop computer.
Note the differences between the clunky stock cast-iron manifolds and Edelbrock’s clean-looking headers with individual tuned runners.
Another benefit of EFI is that it automatically compensates for changes in altitude, so you don’t have fiddle with changing jets when you’re planning on tackling a high mountain pass, or when it comes time to return to lower elevations.
The installation is fairly straightforward, though a bit easier if you remove the fenders first for more access. Some of the bolts may be a bit hard to reach with a standard socket, and you’ll need to install an oxygen sensor on the exhaust system, which requires drilling a hole in it and welding on a mounting boss.
The Edelbrock manifold simply drops in place, the same as the factory one. Just be sure to follow instructions on the gasket and sealant. The wiring harness simply plugs in to a variety of connectors and sensors. You’ll also need to add a block-off plate where the mechanical fuel pump fits on the block, because the EFI system requires a special high-pressure electrical pump and filter. Be sure your electrical system is in good order as well, as EFI requires a strong and steady current to operate properly.
Sources: Edelbrock Corp. • 2700 California Street • Torrance, CA 90503 • www.edelbrock.com
Buy the Pro-Flo Multi-Point Electronic Fuel Injection systemfrom www.4wheelparts.com.
 1. Test-fit the gasket on the on header before bolting it on. |
2. It’s easier to install the headers with the fenders removed (just four bolts to remove each one). |
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3. Ream out the bolt holes if necessary. |
4. Fitting the header on passenger side may be a bit more difficult due to limited clearance for a socket, so you’ll probably need a crescent wrench here instead. |
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5. Torque down bolts on header to spec. |
6. Add oxygen sensor to exhaust pipe. |
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7. Shot of EFI system with manifold. |
8. The old cast iron-intake looks pretty funky compared with the Edelbrock aluminum piece. |
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9. The high-pressure fuel pump and filter are key components in an EFI system. |
10. Place manifold into lifter valley. The new Edelbrock manifold uses stock gaskets and RTV silicone sealant. |
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11. Torque down the manifold bolts to spec. |
12. The ECU installs in passenger side footwell or in the glovebox. Be sure to route harness away from heat, chafing or potential battery acid leaks. |
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13. The Calibration Module plugs into the harness as well on passenger side of cockpit, so the system doesn’t require a laptop computer. |
14. Simply plug in the harness to the fuel injectors, water temp, IAC, and so on. Be sure the electrical system is well grounded and supplying plenty of juice, as EFI needs a strong, steady current. |
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15. Since you won’t be using the mechanical fuel pump any more, you’ll need to install a fuel block-off plate. |
16. The Mallory Pro-Billet electronic distributor is included with the Edelbrock EFI system. |
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17. A 195-degree theromostat is needed to keep engine from running too cold, which would otherwise make the computer run a rich, cold-start mode. |
18. The ignition amplifier is mounted on firewall. |
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Now you’re ready to plug and play. |