4TNV98 Fuel Injection Pump Speed Sensor

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4TNV98 Fuel Injection Pump Speed Sensor

Postby Dnkies » Sun Jan 19, 2020 6:46 pm

Hello Everybody,
I own a 2009 Gehl 603 Excavator that is powered by a Yanmar 4TNV98 motor. I bought the Excavator used with about 1500 hours on it. The tractor started having a reoccurring starting issue the first day I got it home. What happens is this...the tractor will start and run perfectly. Sometimes it will start and stop and then start back up normally. Other times it will start and then when I turn it off and try to start it again, it will act as though it’s dead except all of the electrical components will be fine, it just won’t engage the starter and the fault indicator will flash 6 times and continue to do so, until I turn the key off. Then if I leave the tractor alone for a day or two sometimes even more, the tractor will miraculously fire back up and run flawlessly. There is no rhyme nor reason to the sporadic starting. All of the manuals I have read point to a speed sensor on the injection pump. I replaced the speed sensor and thought the problem was solved since the tractor ran and started great for about a month (20 hours or so), but now is having the same problem. I put a new (third) speed sensor on it and it still won’t start. I am going just trying to figure this thing out. It’s important to note that one the tractor decides to start, it will run perfectly until I turn it off. Then it may or may not start back up. I’m hoping it’s not the CPU or the entire injection pump. Help would be greatly appreciated!

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Re: 4TNV98 Fuel Injection Pump Speed Sensor

Postby winston » Mon Jan 20, 2020 3:55 pm

There are 5 different things listed under the 6 flashes in your manual. I assume you have considered all of those. I know they aren't very specific. If you have changed the speed sensor 3 times I think you need to be looking at connections, battery, starter, etc.

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