Kinsler Handbook #32 May 2025

Kinsler Fuel Injection, Inc, 1834 THUNDERBIRD TROY, MICHIGAN 48084 U.S.A. www.Kinsler.com Phone (248) 362-1145 Fax (248) 362-1032 120 TROUBLE SHOOTING CHART CONSTANT FLOW SYSTEM Fuel level in tank below pump (see reference #2 at bottom of page). Main or secondary poppet stuck open, or spring missing. Main bypass installed backwards or in wrong hose - see reference #2. Loose or damaged pump inlet hose. Idle mixture set incorrectly. Worn pump; pump set for wrong rotation; broken drive. Fouled spark plugs or weak ignition. Camshaft improperly timed. Main or secondary poppet stuck open, or spring missing. Restricted main bypass hose. Plugged or dirty nozzles, nozzle screens, or nozzle hose. Loose or damaged pump inlet hose. Vent in fuel tank too small - see reference #2. Throttle stops not adjusted properly - see reference #3. Throttle plates not synchronized or cross-link not adjusted - see reference #3. Twisted throttle shaft or worn throttle shaft bores - see reference #3. Throttle plates installed backwards or bent - see reference #3. Spring in main bypass too weak - see reference #4. Idle mixture too lean or air leak at manifold gasket - see reference #5. Fouled spark plugs or weak ignition. Main bypass poppet stuck closed or spring too stiff. Main bypass installed backwards or restricted bypass hose - see reference #2. Vent in fuel tank too small - see reference #2. Idle mixture set too rich - see reference #5. Nozzle vents restricted or plugged (nozzles located below throttle plates). Barrel valve spool worn excessively. Idle mixture set too lean or air leak at manifold gasket - see reference #5. Main or secondary poppet stuck open or spring missing. Improper barrel valve spool or linkage geometry. Ignition too far advanced. Bent or leaking intake valve. Camshaft not properly timed. Fouled spark plugs or weak ignition. Throttle plates not synchronized or cross-link not adjusted - see reference #3. Twisted throttle shaft or worn throttle shaft bores - see reference #3. Throttle plates installed backwards or bent - see reference #3. Dirty or bent rod end bearing. Manifold not evenly tightened down. Manifold damaged, bushings loose, linkage geometry incorrect. Bolt securing one of the rod ends overtightened (deformed ball). No shut-off valve or internally leaking shut-off valve. Fuel level in tank above nozzles without shut-off valve. Bad pump seal; leaks into engine (Not on belt drive pumps). Hose between shut-off valve and barrel valve picking up heat; fuel in hose boils, thus expanding into engine. FOR STARTING, IDLE, AND PART THROTTLE REFERENCE © 2020 WILL NOT START WILL NOT IDLE OR POOR IDLE DISTRIBUTION IDLES RICH BACK FIRES WHEN THROTTLES OPEN, OR POOR RESPONSE FUEL DRIPS CONTINUALLY INTO ENGINE WHEN NOT RUNNING STICKING THROTTLE #2 - See “Preferred Plumbing Schematic on Pg. #114 #3 - See “Uni-Syn” on Pg. #61. Note: Even through throttle synchronization only affects distribution at idle, it is very important, since the difference in idling cylinder temperatures that it causes will heat some spark plugs more than others. The warmer plugs tend to overheat during the run and cause detonation, especially in fueler units. The overheated plugs will at least give false readings even after a full throttle run. #4 - See “Bypass valves” on Pg. #88 and #7 See “Basic Adjustments for Constant Flow Metering” on Pg. #108