Results for "surging"

Despite my neighbor's Onan 4000 generator purring like a kitten, mine suddenly developed nasty surging issues yesterday — what's going wrong? It surges when cold, then settles down as it warms up. Under load it surges heavily until the appliance shuts off. Getting worse each day.

What are the main causes of generator surging? Need a step-by-step approach to diagnose and fix this - should I start with the carburetor, fuel system, or something else? …more

Ford V10 surges between 600 and 1200 RPM at idle and gets worse when the engine is warm. Already replaced the IAC valve and cleaned the throttle body with no improvement. Drives fine on the highway but sitting at a stoplight feels like the engine is about to stall. …more

Opened my wallet for a new catalytic converter, cleaned the MAF sensor, checked every vacuum line, and swapped the fuel filter on my 2014 Ford V10 motorhome — still getting P0420 codes and intermittent surging. Some days it runs absolutely perfect, smooth acceleration and no codes. Other days, especially during acceleration, I get this annoying surging that makes driving unpleasant, and that's when the P0420 code shows up on my scanner.

I've been methodically working through potential causes and have replaced quite a bit already: new MAF sensor, both upstream and downstream O2 sensors, checked fuel pressure (it's good), tested plugs and coils, cleaned the throttle body thoroughly, and even replaced the right side exhaust manifold gasket after noticing some seepage there. Despite all this work, I'm still getting the same P0420 code and surging, and my scan tool consistently points to issues on the right bank.

What's really puzzling me is the connection between the surging and the P0420 code - they seem to occur together. Could there be something I'm missing with the exhaust system that would cause both symptoms? I've already addressed the right side manifold, but I'm wondering if there's more to this V10 exhaust system that I should be checking. …more