Land Cruiser Fuel Injection

Back when our '70 FJ40 Toyota Land Cruiser first hit the American shore, it was pretty high up on the techno scale. A basic one-barrel carb and a points distributor made for a reliable, yet not too exciting, performance package on the old straight-six, for both the street and trail. While we love our 'Cruiser, we have always yearned for more power, reliability, and throttle response provided by modern niceties like electronic ignition and fuel injection on the factory mill.

History Lesson
Toyota's inline-six cylinder engines in the F and 2F families are based on the 235ci Chevy I-6 built from 1954-62. Most F and 2F engines in Land Cruisers are fitted at the factory with a two-barrel carburetor. The later model in the '87 wagon's 3F-E finally sported factory fuel injection, but the engine was also de-stroked to turn higher rpm for highway use, resulting in less torque for the trail.

Prior Mods
In the years we've owned this 'Cruiser, we had made other modifications in our quest for power. To help improve the highway power and poor fuel mileage, we had Man-A-Fre install one of its high-compression, Weber-carbureted, rebuilt 2F engines, with an electronic ignition. This modification improved both power output and fuel economy, but did nothing to cure carb stumbling at angles or over bumps.

The Upgrade
Turbo City performed the fuel injection conversion on our pre-smog Land Cruiser using a distributor from Up And Over Innovations to interface between the Toyota engine and the GM computer. Unlike the factory Toyota unit, this distributor doesn't have a vacuum advance since the ignition advance and retard functions are now handled by the GM computer. In fact, the computer thinks it's receiving signals from a '90 V-6 S-10 pickup. Since the GM TBI system bolts onto the intake manifold much the same as a carburetor, the installation is simple. Just replace the distributor, bolt the adapter plate onto the intake manifold, install the TBI unit and a few sensors, add a high-pressure fuel pump, and plug in the new wiring harness and computer. It really is that easy.

The Results
After Turbo City finished the installation, we went for a testdrive. The first thing we noticed was that we had to feather the throttle some when accelerating from a standstill, to avoid wheelspin. Once on the freeway, we found that we could pass cars at will. In addition, the throttle response was very crisp. In stock form, the 'Cruiser would climb steep grades only in Third gear. After our Man-A-Fre upgrades, Fourth gear was usable but we were still at wide-open throttle to make the grade. After converting to EFI, we can climb grades in Fourth gear with enough throttle left to pass the slow movers.

After burning a few tanks of fuel, we also found that mileage had increased almost 4 mpg, from an average of about 15 to 19 mpg. However, during this mileage testing we were light on the throttle, while in normal driving we tend to enjoy the added power, so mileage is more like 17 mpg under normal driving conditions. In our off-road testing, the EFI proved even more helpful. Our 'Cruiser no longer exhibits the tendency to flood on steep accents, descents, and especially in hairy off-camber situations. We no longer need to feather the throttle to keep the motor from loading up, and the engine starts much easier, especially in extreme weather conditions. Best of all, the engine will run virtually upside down if we wanted it to, the only limitation being lack of oil pressure.

EFI Speak
Fuel Injection Glossary

Coolant Temperature Sensor (CTS)
When the engine is cold, as opposed to warm, the CTS sends a different signal to the ECU to richen the fuel mixture, similar to the choke on a carbureted engine.

Electronic Control Unit (ECU)
The ECU calculates the amount of fuel to be delivered by the injector nozzles based on information received from the various sensors.

Idle Air Control (IAC)
The IAC, located in the throttle body, uses input from various sensors to control idle speed through the ECU.

Knock Sensor
The knock sensor acts like a microphone listening for detonation. When detonation is detected, it sends a signal to the ECU, which retards ignition timing.

Manifold Absolute Pressure (MAP)
The MAP senses intake manifold pressure, then sends a signal to the ECU. The ECU then adjusts fuel delivery and ignition timing.

Oxygen Sensor (O2 Sensor)
The O2 sensor is installed in the exhaust. It measures the oxygen content of the spent gases and sends the signal to the ECU, which sends the appropriate signal to the injector nozzle to richen or lean the mixture.

Programmable Read Only Memory (PROM)
The PROM is a computer chip programmed with specific calibration information to meet the needs of a particular engine. The PROM can be compared to carburetor jetting and ignition advance curve. The PROM plugs into the ECU.

Throttle Body
The throttle body houses the injector nozzles. It has butterfly valves and looks like a carburetor, but has no float bowl.

Throttle Position Sensor (TPS)
The TPS is mounted on the throttle shaft and is basically a variable resistor. When the throttle is closed, it sends a low voltage signal to the ECU. When the throttle is open, it sends a higher voltage signal to the ECU and the fuel delivered to the injector is adjusted accordingly.

Turbo City provides a complete system that includes a throttle body, a distributor, sensors, a harness, and everything else you need to complete your fuel injection upgrade.
Turbo City provides a complete system that includes a throttle body, a distributor, sensor
The upgrade to EFI begins by cranking the engine to top dead center (TDC) on the number one cylinder, and then disconnecting the battery so that the motor can't be accidentally cranked over later. Next, the battery and the distributor are removed. When removing the distributor, note the position of the rotor. This is required so that you can index the new distributor correctly. If you don't get it in right, the motor will run poorly or not at all.
The upgrade to EFI begins by cranking the engine to top dead center (TDC) on the number on
Once the distributor is out, you will need to remove the air cleaner, carburetor, and any spacers or adapters under the carb. All you want to see is the manifold opening, because the new components will replace everything from there up.
Once the distributor is out, you will need to remove the air cleaner, carburetor, and any

The stock ignition coil and igniter module can be removed and tossed in the recycle bin. It's best to upgrade to a high-output aftermarket coil. However, if you are on a budget, you can reuse the stock ignition coil until your next paycheck. We kept the Toyota coil to get a truer idea of the performance gained from the EFI upgrade only, but trashed it after crunching the numbers.
The stock ignition coil and igniter module can be removed and tossed in the recycle bin. I
This shows a comparison of the stock distributor (right) and the Up And Over Innovations modified GM electronic distributor. If you look closely, you'll notice that the new distributor has no vacuum advance. The computer (ECU) now handles all the ignition advance and retard functions. This distributor is slightly taller than the stock unit and might interfere with some dual battery trays. If it does, modify the tray. It's worth the effort to get EFI.
This shows a comparison of the stock distributor (right) and the Up And Over Innovations m
Turbo City uses a GM ECU for reliability, durability, and programmability. Turbo City has off-the-shelf, basic PROM chips calibrated to run well in most applications. Each EFI package has a PROM tuned for the vehicle requirements based on application, gearing, and other specifics provided by the customer. Fine-tuning can be done with a call or two, or you can take your truck to Turbo City in Orange, California. The ECU should be mounted in a dry location. We chose to mount it in the glovebox.
Turbo City uses a GM ECU for reliability, durability, and programmability. Turbo City has

The throttle-body adapter plate is bolted to the intake manifold and then the throttle body is bolted on top of this. Install the gaskets between the adapter and the manifold and between the throttle body and adapter. If you don't, you'll get a ghastly vacuum leak.
The throttle-body adapter plate is bolted to the intake manifold and then the throttle bod
The ECU harness has a large plug on one end to connect the motor and sensors with the computer. Since we had previously removed the heater and blower-motor assembly, we ran the wiring harness through the block-off plate that covered the stock hole in the firewall. Turbo City installed a large grommet to prevent chafing of the wires. If you still have the stock heater, you'll need to cut a hole in the firewall to pass the ECU plug and harness through.
The ECU harness has a large plug on one end to connect the motor and sensors with the comp
The throttle-cable guide is bolted onto the base of the throttle body using one of the mounting bolts. The new throttle cable is mounted to the bracket and connected to the throttle. The other end of the throttle cable is routed away from hot or moving parts and connected to the end of the pedal rod as it comes out of the firewall. All of the original throttle-linkage transfer rods are removed, since the cable makes them obsolete. The throttle pedal-rod end may need to be modified on some applications by removing the linkage pivot ball.
The throttle-cable guide is bolted onto the base of the throttle body using one of the mou

The coolant temperature sensor (CTS) must be installed in the side of the thermostat housing in place of the stock vacuum sensor. This is a good time to drain and replace the coolant in the motor. After all, who can remember the last time they had a fresh 50/50 mix in the radiator?
The coolant temperature sensor (CTS) must be installed in the side of the thermostat housi
The manifold absolute pressure (MAP) sensor is one of the critical components of the computer feedback system. In our application it was mounted to the valve cover using the supplied kit hardware for ease of installation, and a hose connects it to the throttle body. Other sensors are mounted to the motor or firewall as required.
The manifold absolute pressure (MAP) sensor is one of the critical components of the compu
The O2 sensor is installed in the exhaust pipe just after the collector. This component tells the computer how much unburnt fuel is in the exhaust so that it can adjust the air/fuel ratio to the ideal 14.7:1. This ratio provides the best power and economy in most situations. You can have the O2 sensor bung welded in by a muffler shop before you begin the conversion if you don't have welding equipment. This is the only welding required.
The O2 sensor is installed in the exhaust pipe just after the collector. This component te

The stock mechanical fuel pump is removed and replaced with a block-off plate, with the knock sensor mounted to it. The new EFI fuel pump should be mounted as close to the tank output as possible. The fuel pump is mounted using the supplied vibration-dampening clamps. The fuel filter shown here is mounted between the fuel tank and the fuel pump. Any fuel filter mounted downstream from the fuel pump must be a high-pressure type and use the appropriate high-pressure EFI hose and clamps.
The stock mechanical fuel pump is removed and replaced with a block-off plate, with the kn
The new electronic distributor must be dropped into the block so that the rotor is aligned the same orientation as the original. We had Turbo City install premium sparkplug wires from DUI. These wires are pre-cut to length and numbered for ease of use. Notice the clearance between the distributor and the dual batteries--there is plenty of room using this system, but it might not be in all dual battery systems.
The new electronic distributor must be dropped into the block so that the rotor is aligned
The completed package mounted with the throttle body in place and the new K&N air cleaner mounted on top looks trick. While the filter looks small, the K&N passes enough air for a ski boat at wide-open throttle.
The completed package mounted with the throttle body in place and the new K&N air cleaner

Electronic Hand Throttle

The only concern we had with the EFI upgrade was the high idle speed for off-road use. With our carbureted 2F we were able to lower the idle speed all the way down to about 400 rpm, which was great for crawling on the trail. With the EFI, the idle speed was up around 650 rpm; a touch high for our taste. Turbo City can set up the system to idle at any rpm, but any lower than 650 rpm would result in a loss of streetability.

To handle our trail needs, we installed an electronic hand throttle (EHT) from Off Road Engineering. This unit plugs into the EFI harness between the computer and the idle air control (IAC). The unit has two switches on the face, one for on/off and one to raise or lower the idle speed (a red light indicates that the system is active).

Max rpm varies by engine type. With the shifter-mounted auxiliary idle control lever you can control the idle without taking your hand off the shifter. We can control our engine idle speed from virtually zero to 3,000 rpm with our fingertips. It's even smoother than our old cable-style hand throttle, and unlike the cable unit, we can lower our rpm if needed. Also available is an optional underhood wired remote that can be used to increase the idle when using engine-driven air compressors or mobile welders, without the need to reach inside the cab.