hitachi ex75ur - zexel 101492-0992 fuel pump issue

[Walkerfarm]

Hey wondering if anyone can offer advice and help. I have a hitachi ex75ur digger than ran low on fuel and had a loss in power. After cleaning both banjo bolts, clearing the fuel line from tank, replacing the fuel filter and bleeding the engine I got it running. The problem is the engine is now over running and running at full blast and about 50% more. It feels like its getting way to much diesel. Is there any way of reducing or adjusting this?

digger - Hitachi ex75ur
engine - Isuzu 4JG1NAA
diesel pump - Zexel 101492 - 0992

Any help or advice gratefully received

Ken

 

[Walkerfarm]

fixed! loosen nuts 136 and 138, adjust 135 to set diesel flow and tighten up again happy days.

 

[Diesel Dave]

Welcome to HEF Walkerfarm
Thanks for following up with the fix !

 

[partsdic]

• Check Throttle Linkage: Ensure the throttle linkage is not stuck or binding, causing it to remain open.
• Inspect Injection Pump: Check for any issues with the Zexel injection pump, including stuck components or damaged parts that might be causing excessive fuel delivery.
• Adjustments: Some injection pumps have an adjustment screw for controlling fuel delivery. Consult the engine's service manual or a qualified diesel mechanic to properly adjust it if needed.

 

[thepumpguysc]

That is known as a “buffer screw”.. it’s to keep the engine from surging at low idle..
But if it worked for u, great..

 

[Driver2022]

How do you increase the fuel in this pump to give a few more hp? Which number do I turn 1/4 turn ?

 

[thepumpguysc]

336.. but it’s got a STEEL CAP on it that u won’t be able to get off..
If by the grace of God u do get it off.. u turn it “IN” 1/2 turn..