My Isuzu 4FA1 diesel is hard to start and I noticed that there is no fuel flow in the return line. Are the injectors needing cleaning or could it be something else? Any help appreciated. Thanks.
Hi Cathead, I'm in the same case as yours on my Isuzu campo pickup 4JG2. The fuel system is hard to prime ; once done it starts well. After engine stops a few minutes, it loses prime rapidly and I need to insist to start it again. The day after, it needs to be primed again. All fuel hoses are replaced and checked with transparent ones (no air) ; fuel filter and hand primer too. Then I checked the return rail line from the injectors and surprisingly there is no fuel coming out. Did you find how to solve this issue ? Thanks for your help. Greatings from France
Some fuel systems have check valves that start to leak fuel back to tank. You will have to get some fuel system schematic for your exact unit to find out what is hiding where on it. Simon C
HCampo , Ti invio MANUALE DI SERVIZIO per ISUZU 4JG2 Regards
If you’re checking the return fuel after the injection pump, there is a tiny orifice in the return banjo bolt.. U probably aren’t gonna see a lot of return.. If priming is an issue, if there’s any rubber lines from the tank to the inj pump, you could plumb in a low volume pressure pump and have it run off the key switch..