General Installation
When installing the injector on the blower or tunnel ram manifold, tighten the bolts evenly to prevent distortion. A gasket or silicone seal must be used on the bottom of the injector.

Metering Valve
This metering system uses two return lines, each with a check valve. The check valve on the bottom of the metering valve is for the idle circuit and is set to open at 15-20 psi. The check valve in the tee fitting is the main jet return and opens at 1-2 psi. The main bypass jet is installed in the fitting under this check valve. A blank bypass jet is installed under the 9/16 hex plug on the metering valve and should not be removed.

Main Bypass Pill
Every Enderle fuel injector is furnished with a set of bypass pills. This bypass controls the fuel mixture at full throttle and has very little effect on the idle. Use a smaller bypass to richen the fuel mixture and a larger bypass to lean it. When installing the bypass, make sure it is seated at the bottom of the threads.

Idle Control
The idle mixture is controlled by the turnbuckle on the side of the injector. To richen the idle, rotate the turnbuckle towards the rear of the injector, (shortening the linkage leans the mixture, lengthening richens the mixture). This adjustment is for idle and throttle response only and has no effect on full throttle operation. The idle speed is controlled by the butterfly shaft stops on each side of the injector.

High Speed Bypass System
Certain applications require the use of a hi-speed lean out. This consists of a bypass pill controlled by a high pressure check valve which leans the fuel mixture at high RPM. The check valve pressure is adjusted with shims to tailor the fuel curve to the engine’s requirements. The check valve opens when the fuel pressure is able to overcome the spring tension. The bypass pill controls the volume of fuel returned. Adding shims will make the check valve open at a higher RPM. Removing shims will make the check valve open at a lower RPM. The hi-speed should be thought of as a fine tuning device. The main bypass pill is the primary control of the overall fuel mixture.

Maintenance
The fuel system should be drained between races. It is important to lubricate the fuel pump with Prolong SPL100 or some other type of lubricant. Remove the inlet line from the metering valve and lubricate the metering piston to prevent stickiness and drying out.

* WARNING *
You must use a 3-way fuel shutoff with a return. A 2-way style shutoff will damage the fuel pump.