How to Install the Holley Terminator EFI on a Small-Block - Feeding Fuel

A high-tech EFI System teaches our small-block a few new tricks

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Aeromotive Stealth Fuel Tank 2/27

15. One super easy and great looking way to address the fuel system is to go with something like this Aeromotive Stealth fuel tank (PN 18567, $700). It's built around a powdercoated Tanks Inc. fully baffled, replacement gas tank. Inside, there's a 340 Stealth turbine-style electric fuel pump and a GM 0 to 90-ohm sending unit. This is an especially good idea if high-g maneuvers are planned since the design ensures the pump stays submerged even at low fuel levels. It came to us fully assembled and ready to install. We hit up Ground Up for their gas tank installation kit (B13-2-B, $13), which included new foam isolator pads.

Three Ports 3/27

16. The pump had three ports that needed to be dealt with: feed line, return line, and vent. The ports were ORB-06 style, so we had to make a run down to the local speed shop for some fittings. The system supports naturally aspirated EFI engines up to 850 hp, so it's more than capable of feeding our small-block. We should note that the Holley harness had a wire (green) that could directly power a pump up to 15 amps. The Aeromotive pump drew right around 15 amps, so we decided to play it safe and install a relay and use the green wire to trigger it. If you use the inline pump that comes in the Holley kit, then you're good to go since it draws less than 10 amps.

Billet Holley Fuel Regulator 4/27

17. We mounted the billet Holley fuel regulator to the firewall above the heater box. We also tossed on an Aeromotive 100-psi fuel pressure gauge. It's a great spot since Holley recommends that it be installed after the throttle body. In our case, we decided to use the Camaro's existing hard line as the return and run the new Earl's Super Stock hose for the feed. We felt more confident relying on the Earl's fittings to hold the EFI pressure rather than the hose clamps on the factory hard line. The 40-micron Holley filter was plumbed into the feed line from the tank.

Fuel Pressure Inducer 5/27

18. Since we wanted to be able to read fuel pressure with our handheld unit, we installed a Holley 100-psi fuel pressure transducer (PN 554-102, $112) in the fuel rail. If you want to skip it, the system will run fine, but you'll get an "LEr" message on the handheld display.

Mechanical Fuel Pump 6/27

19. We also removed the mechanical fuel pump and pushrod. To seal up the block, we used a plate and gasket that came in the Terminator kit.

Stealth Tank 7/27

20. And here's our Stealth tank installed under the '67. The old straps looked like crud on the freshly powdercoated tank, so we grabbed a set of stainless straps from Ground Up (PN XTS-F67S, $45).

Vent Fitting 8/27

21. The tank included a small vent fitting, but we really couldn't find a good spot to mount it. The problem was finding a spot higher than the gas cap that didn't let fumes into the trunk and was safe from road debris. The solution was this sweet billet tandem tank from Brian Finch over at Hot Rod Transformations. This is a great product since it mounts in the high area of the trunk and still vents to the outside of the car. Another big benefit is that, in addition to the fuel vent, it also handles the differential. The tank runs about $219 and comes with instructions and a mounting template.

Testing And Tuning

A new EFI system is useless if you can't get it up and running. And in this regard, the Terminator system excels. By setting some basic parameters with the handheld, the ECU is able to get the car started, and from there it learns as you idle and drive. For the system to enter learn mode, all the sensors must be plugged in, the unit has to have a clean tach signal, and the ECU must sense a water temperature of at least 160 degrees. It's not complicated, but it is a process, and thankfully the procedures, along with a troubleshooting guide, are well-documented in the installation booklet.

Here are some of the basics.

Holley Efi Sytem Camshaft Ype 9/27

22. In addition to tuning, the handheld also has monitor and gauge functions. These are very handy for seeing what's going on with the system and troubleshooting, if necessary. Using the calibration wizard, we started by answering some basic questions, such as engine displacement, what style camshaft, system part number, ignition source, etc.

Holley Efi System Main Menu 10/27

23. The next step in firing up the Camaro was to set the TPS. Once we got the message that the TPS Autoset was successful, we were ready to fire the engine. We then followed the suggestions for letting the system start the self-tune process. Once fired, we also checked the car for any coolant or fuel leaks and opened the Monitor menu on the handheld to make sure the sensors were all reading correctly. This is where we figured out that the temp sender needed to be moved forward to a hotter area of the intake manifold.

1967 Chevy Camaro Side View 11/27

24. The Camaro was running better, but was getting erratic IAC readings along with a high-idle rpm, and the system was stumbling a bit. To troubleshoot the system, we took the Camaro to the guys at Westech Performance in Mira Loma, California. Chassis dyno tech Eric Rhee was able to plug his laptop into the Terminator ECU and see a ton of information not available on the handheld.

Base Sytem Fuel Flow Rate 12/27

25. For the system to work, it needs a good tach signal. We had the yellow wire on the harness hooked to the negative post on our coil. Normally this is fine, but Eric found we were picking up excessive "noise," and that wasn't making the Terminator happy. The solution ended up being simple. The Terminator system has a pigtail for use with ignition boxes like the MSD 6A. The wires in this loom, unlike the yellow wire we were using, are shielded, so Eric tagged a wire from the ignition box pigtail and ran it to the positive post on the coil. We then used the handheld under Ignition Setup to tell the system we were getting our tach signal from a CD ignition box.

1967 Chevy Camaro Rear View 13/27

26. With a clean tach signal, the system was able to tune as we drove around. The more we drove the Camaro, the better everything ran. One thing that helped was to vary how we drove the car, so the system could "fill in more blanks" in the tune. Now the Camaro fires up just like a new car and runs silky smooth. And while we're pretty sure the engine didn't pick up any power, we did notice the engine's powerband felt a bit different—mainly more responsive. We also noticed a slight improvement in fuel economy, but our lack of an Overdrive gear made that a bit hard to quantify. What we do know is that our Camaro's driveability is much improved, and that makes the effort more than worthwhile.


Westech Performance
Mira Loma, CA 91752
Earl's Performance Plumbing
Bowling Green, KY 42101
Lenexa, KS 66214
Holley Performance Products
Bowling Green, KY 42101
Finch’s Hot Rod Transformations
Lokar Performance Products
Knoxville, TN 37932
Optima Batteries
Milwaukee, WI 53209
National Parts Depot - California
Ventura, CA 93003


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