Hitachi EX75 UR

[Oakfield]

Hi,

I had a very reliable 1996 machine, however problems now beginning to surface, first thing was the level sensors, so had a guy out to disconnect them so she could work again, next came the trottle which is hydaulic or fly by wire, had a guy out again he changed over a new hydraulic trottle control and no difference so the deduction was electrical again. This time he said it mus be the brain (main control board), anyway that cost to much to try so still have a rope for a trottle!!, last week I started the machine and after 10 sec she conked out and wornt start since however it is turning over, the selonid fuse is ok for the fuel pump. Pretty sure its not getting fuel, I removed the filter checked for water (none) check were injectors getting fuel (no) so guessing the pump, however Im asssured by a hitachi guy that he never has a pump go in all his years working on them. Anyway the pump is awkward to get to and so want to know if eletrical could be the issue and if anybody else had experienced probs with this model? Shes a jap import 1996 with a one click to start never failed nissan engine. up to now anyway :)) Thanks

[Muz]

I'm guessing you don't see any smoke from the exhaust when you turn it over ? Could be a failure of the solenoid if the power supply is good. Ive had some that the pintle gets bent during operation, causing it to stick.

[Locofitter]

Did the guy you had out connect a Dr.EX diagnostics computer into the machine?

From your post, it appears you're not getting fuel. Have you started on the basics first? IE have you primed the system of fuel? If you're unsure how to do this: Loosen fuel return bolt and bleeder bolt and pump away until pure fuel only flows then do up the fuel return bolt. Pump again until only fuel (no air) flows from bleeder bolt then also tighten this bolt.
Just as a double check I then undo one of the injector connectors on head of the engine and then pump again, purely to make sure the entire fuel delivery system is free of all air bubbles.

Be worth cracking out the fluke and start tracing your voltages.
I suspect no fuel delivery would have something to do with a fault condition relating to the Engine Control angle sensor.

Unsure if you fixed your issue and I only have schematics for Isuzu engined machines.

[v8druid]

I'm guessing you don't see any smoke from the exhaust when you turn it over ? Could be a failure of the solenoid if the power supply is good. Ive had some that the pintle gets bent during operation, causing it to stick.

stop solenoid'd be my first 'go to'., too Muz