QuestionI think I have a Honda TRX350 fuel pump or wiring issue.
I did the normal test for the fuel pump from the honda shop manual. I get 12V before the fuel pump shutoff relay. I get 3V after the relay at the harness plugs where the fuel pump attaches. I replaced the fuel pump cutoff relay with a brand new one.
Symptoms: It will not start except after a very long number of starting revolutions...60 or more. I used a spray bottle and sprayed gas directly into the carb and it fires right up and runs until the fuel is expended. After I get it running, If I let it sit a couple of hours, it has the same hard starting issues again. Its like the bowl doesn't keep fuel in it or the fuel pump volumn is not high enough or...?. I don't see any signs of leaking on the carb.
Bad ground? Bad fuse? What should the voltage be at the fuel pump at the end of the harness connectors? I get 3V. Book says it should have battery voltage.
Thank you for any suggestions you might have.
AnswerDave, I am really more of a vintage Honda street bike guy and not ATV/ATC and Goldwing/off-road expert... even though your TRX is 23 years old....
A relay is a relay, however and unless there are some resistors inside, battery voltage should be going in and most if it back out again, measured with a volt meter.
If the pump is drawing a lot of current/voltage, then you might be seeing the results on that side of the relay. The pump could be either shorting out or have an open/high resistance circuit that is out of tolerance from specifications.
Putting the fuel pump output line into a container, you should be able to determine if the pump is putting out sufficient output (volume) and attaching the line to a vacuum/pressure gauge will give you the output pressure. You are just feeding a carburetor, so you don't need a lot of pressure... only volume.
A bad ground can show up with weird symptoms, for sure, including low voltage readings. Rarely are fuses "bad" but I have seen them with hairline cracks through the middle, instead of being blown out completely. Test everything with meters and jumper wires to known good grounds.
Bill Silver
