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Junkyard Fuel Injection Conversion

Dino the Fuelie

Verne SimonsPhotographer, WriterTrenton McGeePhotographer

Fuel injection, it’s the wave of the future. Well, at least it was in the late 1970s and early 1980s. This was really the dark ages of fuel delivery in cars and trucks. Carburetors worked pretty well until automotive engineers had to worry about fuel economy and vehicle emissions. The first band aid to improve economy and emissions was to load engines with emissions-choking devices like smog pumps, huge EGRs, stuffy catalytic converters, and computer-controlled carburetors. None of this worked too well until electronic fuel injection introduced atomized fuel and electronic feedback systems. Efficiency went up and emissions went down with a system that could properly self-regulate fuel air ratios.

Enter Dino the Dinosaur, our 1970 Chevrolet Suburban 4x4 with a long story to tell. Predating both emissions controls and expensive fuel, Dino drinks gasoline like a fish. The truck originally came with a 307 V-8 fueled by a one-barrel carburetor. In the late 1980s the tired 307 was replaced with a remanufactured Chevy 350 and the one-barrel carb was swapped over to the new engine, which delivered fuel to the newish engine for the next 31 years without too much drama. Recently the carb was in great need of a rebuild, but we wanted to give Dino more power and better fuel economy and to improve drivability. We dabbled with the idea of adding a Motorcraft/Autolite 2100 two-barrel or even a Quadrajet four-barrel carb, both of which are known as good off-road carbs.

Another alternative that would bring Dino up to the standards of the late 1980s and early 1990s was to do a junkyard rebuild and install a GM throttle body electronic fuel-injection system. We have dabbled in GM TBI a few times on other projects and knew it was a simple, reliable, and fairly efficient system. The best part is there’s aftermarket support for GM TBI and the systems litter our local junkyards. Unfortunately it’s not quite as simple as bolting a throttle body onto the engine, but with a little research we were able to piece together a running system that could be replicated for virtually any V-8 with a displacement around 260-400 ci. Also GM TBI has a rudimentary onboard diagnostics system that can help indicate any problems with the system, and the system can be modified to run on a wide variety of makes and sizes of gasoline engines.

After gathering the parts needed to add GM TBI from our local junkyard we began piecing the system together. If used parts make your skin crawl, you can order a full TBI retrofit kit from a company like Howell EFI, which bases its system off the same tried-and-true GM TBI system we pieced together. We decided to do a little bit of both using some new and some used parts to piece our system together.

TBI Parts We Used on Dino

… except for those we forgot. Many sensors and parts can be sourced from the internet or your local parts store for a 1987-1995 Chevy 1500 Suburban with a 5.7L V-8.

• Throttle body with injectors (junkyard)
• Throttle position sensor or TPS (mounts to TBI) (junkyard)
• Idle air control motor or IAC (mounts to TBI) (junkyard)
• Wiring harness (Painless Performance)
• Temp sending unit (parts store)
• O2 senor (parts store, or junkyard if you’re feeling lucky)
• Oil pressure switch (we didn’t bother; Dino has an idiot light, but you could acquire the switch from a junkyard or parts store)
• VSS (Internet, Howell, Novak)
• Intake or adapter plate (ours came from Edelbrock)
• Knock sensor (junkyard or parts store)
• Knock sensor controller (junkyard or parts store)
• Fuel pump (parts store; ours is for a 1991 Suburban in-tank unit with tank; for inline use, a late 1980s Ford F-250 fuel pump)
• Fuel filters (parts store)
• Fuel line and fuel fittings (parts store or online)
• Coil (PerTronix)
• HEI distributor (PerTronix)