z930m EFI loses power after 20 minutes

[FisherCat930]

What the fault code the engine is throwing?

Last time I took it into the shop they said it was:
0174 - Lean fuel condition at high load (open loop)

 

[FisherCat930]

Here's one of the plugs. Seems a tad white to me.

 

[StarTech]

Have all the following items?

 

[ILENGINE]

I am leaning toward a faulty EFI pump. Also keep in mind there is also a filter inside of the EFI pump that is non serviceable, and will clog if the wrong inlet fuel filter has been installed. If I remember correctly the internal filter is a 10 micron, and they recommend a 2 micron inlet filter on the Kohler engine.

There was a case of if I remember correctly it was an older CH26 that would run great for awhile and then loose power and throw engine codes. After running for like an hour the fuel pressure was dropping from 43 psi to 13 psi.

 

[FisherCat930]

I am leaning toward a faulty EFI pump. Also keep in mind there is also a filter inside of the EFI pump that is non serviceable, and will clog if the wrong inlet fuel filter has been installed. If I remember correctly the internal filter is a 10 micron, and they recommend a 2 micron inlet filter on the Kohler engine.

There was a case of if I remember correctly it was an older CH26 that would run great for awhile and then loose power and throw engine codes. After running for like an hour the fuel pressure was dropping from 43 psi to 13 psi.

The EFI pump is over $300 so I may resort to getting the $80 knockoff from Amazon just to see if it fixes the problem.. even if only works for a few months.

 

[FisherCat930]

Have all the following items?
View attachment 60199

I'll look into these as well.

 

[hlw49]

Try unplugging the O2 sensor and see how it runs.

 

[Gord Baker]

If the PTO bogs it down perhaps you have a spindle or other bearing seizing up? Loosen Deck Belt and make sure all blades turn freely. A lean condition may cause backfire.

 

[sgkent]

so the problem doesn't go away when the PTO is disengaged, it merely takes the load off the engine, allowing it to speed up. Maybe as others suggest, post the fault code.

 

[hlw49]

Code 0174 Component: Fuel System Fault: Lean fuel condition Condition: Fuel inlet screen/filter plugged, low pressure at high pressure fuel line, TPS malfunction, shorted connection or faulty sensor. Conclusion: TPS Learn Incorrect ● Lean condition (check oxygen sensor signal with VOA and see Oxygen Sensor). Engine Wiring Harness Related ● Pin circuit wiring or connectors. ECU pin Black 10, 12, 16 and 17. Low Fuel Pressure ● Plugged fi lters. ● Bad lift pump. Oxygen Sensor Related ● Sensor connector or wiring problem. ● Exhaust leak. ● Poor ground. Poor system ground from ECU to engine, causing rich running while indicating lean. Fuel pump module connection. See Fuel Components. Code 0201 Component: Fuel Injector Fault: Injector 1 Circuit Malfunction Condition: Injector damaged or faulty, shorted

Never attempt to disassemble ECU. It is sealed to prevent damage to internal components. Warranty is void if case is opened or tampered with in any way. All operating and control functions within ECU are preset. No internal servicing or readjustment may be performed. If a problem is encountered, and you determine ECU to be faulty, contact your source of supply. ECU pins are coated at factory with a thin layer of electrical grease to prevent fretting and corrosion. Do not attempt to remove grease from ECU pins. Relationship between ECU and throttle position sensor (TPS) is very critical to proper system operation. If TPS or ECU is changed, or mounting position of TPS is altered, appropriate TPS Learn Procedure must be performed to restore synchronization. Any service to ECU, TPS/Throttle Body (including idle speed increase over 300 RPM), or fuel pump module replacement should include ECU Reset. This will clear all trouble codes, all closed loop learned off sets, all max values, and all timers besides permanent hour meter. This system will NOT reset when battery is disconnected! ECU Reset Procedure 1. Turn key/ignition OFF. 2. Install Red wire jumper from Kohler EFI service kit on to service port (connect white wire to black wire in 4 way diagnostic port). 3. Turn key/ignition ON, then OFF and count 10 seconds. 4. Turn key/ignition ON, then OFF and count to 10 seconds a second time. 5. Remove Red wire jumper. Turn key/ignition ON, then OFF and count to 10 seconds a third time. ECU is reset. A TPS Learn Procedure must be performed after ECU Reset. TPS Learn Procedure 1. Turn idle screw clockwise one full turn prior to key/ ignition ON after ECU Reset. 2. Start engine, run at low idle until engine is warm. 3. Idle speed must be above 1500 RPM. If below 1500 RPM, turn idle screw up to 1700 RPM and then shut down engine and perform ECU Reset again. 4. Restart engine, adjust idle speed down to 1500 RPM. Allow engine to dwell at 1500 RPM for about 3 seconds. 5. After this, adjust idle speed to final specified speed setting. 6. Turn key/ignition OFF and count to 10 seconds. Learn procedure is complete.