Kinsler_Handbook_#32 December 2017

Kinsler Fuel Injection, Inc, 1834 THUNDERBIRD TROY, MICHIGAN 48084 U.S.A. Phone (248) 362-1145 Fax (248) 362-1032 60 UNDERSTANDING THE IDLE Idle Speed is a balance of throttle plate opening and fuel rate. The unit should idle near the desired RPM with the proper amount of fuel. Never richen up the fuel rate to reduce the idle RPM; back out the idle screw instead. Mechanical fuel injection systems require a rich idle mixture for optimum throttle response since they do not have an accelerator pump. Any time the idle speed is adjusted, the fuel rate at idle may need to be readjusted for best throttle response... set it so you get the best response when you snap the throttles open with the vehicle out of gear. Engines equipped with an automatic transmission require richer mixtures “out of gear” to compensate for the load of the transmission when “in gear”. THROTTLE SYNCHRONIZATION AT IDLE If the throttle plates are not synchronized at an idle, then some cylinders will be richor lean compared toothers... thesewill NOT developmaximum power as quickly as the other cylinders when the engine is brought to wide open throttle. SometimesatW.O.T. theproblemclearsupquickly, sometimes NOT. A rich cylinder may take a fraction of a second to several seconds to burn off the excess fuel and raise combustion chamber temperature. A cylinder running lean at an idle is a prime candidate for serious engine damage. When the engine is brought to wide open throttle, the overheated spark plug may cause detonation. SOLVING SYNCHRONIZATION PROBLEMS Make sure the throttle plates are not installed upside down. They are machined at an angle! (seeTHROTTLE PLATES on Page #52). Check the intake manifold for gasket leaks; worn shaft bushings, shafts, plates, etc. Loctite ® #271 must be applied to secure the throttle plate screws Check synchronization side to side using feeler gauges Fig. 1 © 2017 See Pages #58-59 “HOW TO SETUP LINKAGE” 1) Disconnect the cross hex link bar and work on each side of the injection unit separately. 2) Back off the throttle stop idle screws all the way, so the throttle plates will contact the throttle bores. 3) Loosen or remove all the throttle plate screws. BE VERY CAREFUL NOT TO DROP THEM INTO THE ENGINE! Any New Kinsler manifold or manifolds serviced by Kinsler have Loctited ® plate screws. The screws may require heat to break the bond. 4) While holding the throttle shaft in closed position, tap the shaft back and forth lightly to allow plates to center themselves in the throttle bore and rotate plate in the throttle bore till gaps are equal on both sides of the plate at the location shown in Fig 1. 5) Install throttle plates and tighten screws usingLoctite® #271. 6) Do the same to the other side of the manifold. 7) Reconnect cross hex link bar. Adjust it so both sides maintain the closed position. 8) Turn idle screws “in” to raise plates just off the throttle bore. Depending on the engine displacement, throttle size, and idle speed you want, the throttle plates will need to be open about .002” to .008”. A small block Chev will require about .003” - .004” 9) Check that both sides of the injection open at the same rate. See How To Set Up Linkage on Pages #58-59. Do this only if you can’t synchronize the throttles using the Uni-Syn. If no problems are found: