How to Install the Fast EZ-EFI Unit - EFI Evolution

We ditch our archaic '80s-era throttle body injection for a more capable EFI system that'll make the most of our engine.

Patrick Hill Feb 5, 2014 0 Comment(s)
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Ok. Let's start by stating the obvious … fuel injection has a come a long way since the '80s. You know it, we know it, and anyone with a car built in the last 10 years knows it. So, we'll skip the history lesson and rehash of what everyone knows already when it comes to EFI.

Here we have our '92 Camaro RS. A factory 305/automatic car, we picked it up for $800. No rust, never been in an accident, 205k miles on the odometer, and in overall good shape other than a worn out interior and non-functional power windows. But in the world of third gens, unless you've got manual windows, at some time or another yours stopped working too.

The factory L03 engine was rated at 170 HP, not bad for the time when it came to a base V-8, and healthy on the torque side. The L03 was the optional engine for the RS model (TPI engines could only be had with the Z28) and came equipped with a throttle body injection unit controlled by GM's Histrionics computer system. For its day the system got the job done, and since most TBI engines were left alone mod wise, they were more than adequate. Today there are still millions of them out there doing the job of mixing fuel and air for the engines in various GM cars and trucks.

But for anyone looking for performance, this system just isn't up to the task. After we installed a new Chevrolet Perofrmance Fast Burn 385 crate engine in place of the tired 305, we left the old TBI system in place to see how it would respond. While the car ran fine, we could tell the TBI unit was choking the engine for power, and the dinosaur EFI system did not really give us anywhere to go for trying to tune it. Years ago there were plenty of companies burning performance chips for older GM computers, but today most of them are gone.

Looking for the best solution that would make future mods easy, we decided on FAST's EZ-EFI self-adaptive fuel system. Using a high-pressure, fuel injector-equipped four-barrel throttle body, EZ-EFI is FAST's user friendly system that requires no laptop tuning, no complicated tuning software, and can be installed on almost any engine as long as the intake will accept the throttle body. It features an adaptive learning system that, once a set of base parameters are set (engine size, number of cylinders, etc.) will handle adjusting the various parameters until it finds the optimal settings for everything. All you have to do is drive the car around while the computer does the work. It's that simple.

Follow along and we'll show you…

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1. The starting point for our install is FAST's (Fuel Air Spark Technology) EZ-EFI unit. This system is one of the easiest ways to either convert from a carb to EFI, or switch from a limited factory EFI system (like in our case) to a modern one with programmability, and better adaptability to performance mods. The system uses a throttle body equipped with fuel injectors and sensors, with a Holley base flange. This gives the EZ-EFI system an almost universal application, as long as your intake can accept a standard Holley flange.

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2. The EZ-EFI kit includes a fully labeled wiring harness, tach driver, O2 sensor, fuel pump, and the various parts and pieces needed to install the system.

1992 Chevrolet Camaro Remove Tbi 4/47

3. The first step is clearing away all the factory TBI junk, then pulling the manifold. The old TBI system was fine (though not spectacular) for running the stock 305, but with our Chevrolet Performance crate engine, it just can't keep up. Plus, there's virtually no tunability with the factory system, leaving us nowhere to go if we add any other engine mods.

1992 Chevrolet Camaro Factory Fuel 5/47

4. We'll end up reusing the factory fuel lines coming from the tank, so after disconnecting them from the engine lines we covered them up and secured them out of the way.

1992 Chevrolet Camaro Factory 6/47

5. Next to go is our factory distributor. The EZ-EFI system doesn't control timing or spark advance, and uses a standard HEI-style distributor and coil.

Holley Street Dominator 7/47

6. Replacing our TBI intake is this Holley Street Dominator unit, part no. 300-64. It's for '87-up small-blocks, and uses the later model A/C and alternator mounting provisions, along with having a port for EGR, and all the runner vacuum taps needed.

Perfromance Distributors Billet Small Cap Hei 8/47

7. For ignition we went with a Performance Distributors billet, small cap HEI unit with vacuum advance and remote coil. It has a simple, three-wire hook up that'll interface with our EZ-EFI system for power, and provide plenty of spark energy to let our small-block make the most of the new fuel system.

1992 Chevrolet Camaro Fast Throttle 9/47

8. The FAST throttle body is pretty much self contained, with all the EFI sensors and fuel injectors already bolted on. It simply drops onto the intake and gets bolted down. If you're running a carb equipped engine that already has four-barrel linkages, you won't even have to change those to work with the FAST throttle body.

1992 Chevrolet Camaro Coolant 10/47

9. Once the intake was secured with new gaskets, we installed the included coolant temp sensor, along with our other coolant fittings, plugs, and vacuum hookups.

1992 Chevrolet Camaro Fast Throttle Body Fuel 11/47

10. The FAST throttle body can be set up to have the fuel line connection for the fuel rails on either side. We had to switch ours because the connection interfered with the throttle linkage.

Ez Efi System Control 12/47

11. The control harness for the EZ-EFI system comes fully labeled, so you know instantly where all the connections go with no mystery. While not fully plug-and-play, EZ-EFI has most of the work already done for you, with only some simple wiring mods on the car's factory harness necessary. If you're running an earlier, non-computer controlled vehicle, a lot of this you won't have to deal with.

Ez Efi System Control Harness 13/47
Mount 14/47

12. We decided to mount the ECM for the system to this bracket on the driver's side, outboard of the power brake booster. This keeps the ECM in a safe place shielded from rain, debris, and just about anything else that could harm it.

Mount Ecm Drivers 15/47
Tach Rpm Module 16/47

13. This tach/RPM module has to be installed so the ECM gets RPM data, and the factory tach also still gets a signal. Per the instructions and the labeled harnesses, it hooks into the EZ-EFI harness and the new coil.




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