Pressure surges up and down? - Karcher G 2600 VH Gas Pressure Washer

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Do It Yourself Diagnosis and Repair

The oil pressure quage is moving around because the engine is slowing down and speeding up. As far as the idle surging goes try this.

It's surging... your carburetor needs to be serviced. It's not giving the proper air fuel ratio to the engine...

BriMaxSmallEngineRepair
Gibbstown,NJ

Jeff I am having the same problem. Have you found a fix for this yet? your post is right on but for some reason we are the only two withthis problem and my local jd dealers have never seen this. , Brent

CLOGGED FUEL FILTER OR WEAK FUEL PUMP CAUSE CAR TO HAVE LACK OF POWER AND SURGE.CHANGE FUEL FILTER,CLEAN FUEL INJECTORS WITH CAN SEAFOAM BY ADDING TO 3/4 TO FULL TANK OF GAS.CHECK FUEL PRESSURE SHOULD BE 41 - 47 PSI FOR 2.0L OR 3.1L ENGINES AND 9 - 13 PSI 2.2L TBI INJECTION SYSTEM.IF FUEL PRESSURE GOOD CHECK TRANSMISSION FLUID LEVEL.FAULTY TORQUE CONVERTER WILL CAUSE LACK OF POWER AND ENGINE SURGE.A STOPPED UP MUFFLER OR CATALYTIC CONVERTER WILL TAKE SLOW CAR DOWN MAKE IT SPEED UP SLOW DOWN SPEED UP SLOW DOWN.

change the sparkplug

might be ur throttle position sensor

When your running out of gas the dirt, grime, and gunk is all you have left except water and that may cause it to surge then slow down irrelevant to the gas pedal pressure.
I've had a similar problem when I ran out of gas
I would try a can of expensive fuel cleaner and a can of dry gas before anything else but that's just me!

most likely idle air control sensor or low engine coolant I know sounds funny but IAC uses coolant to regulate idle. Idle air control valve or throttle body positioning sensor.

Try a simple test. It is ok to run the pump without water for a short time. Check idle speed without water in system to see if enginet surges. If it does not surge, then most likely the unloader/ pressure valve is causing the engine to surge when in the unloaded state. Life of unloader /pressure valve is shortened by letting system bypass for long periods of time. Enjoy