I have a really weird issue with my 2003 Ford Focus. Manual transmission, just over 50,000 miles. I’ve been noticing a stumble or hesitation (like the engine is cutting out) at steady speed, but ONLY when it is snowy out, more if it’s windy as well. I don’t recall that this happens if it’s rainy or foggy. All maintenance is performed as specified, to include air filter changes. Any ideas?
I’d start with a throttle body cleaning.
The problem might be with the Crankshaft Position Sensor.
If the computer loses the signal from this sensor even for a nano-second, the computer see’s no reason to operate the fuel and ignition systems. So the engine can seem to shut off during the event.
You state this occurs when there’s snow and wind and not when there’s rain and fog. When there’s snow it’s below freezing. And when there’s rain it’s above freezing.
Crank sensors can be effected by temperature.
Tester
Good ideas above. If those don’t work, consider the possibility of an high voltage ignition component that is getting damp. That symptom would be worse when it is windy/snowy as the snow might be being blown though the front grill and land on the sensitive spot, melt, and cause an ignition misfire. Usually that would throw a diagnostic code. But not always, esp if it is just temporary. Spark plug wires, coils, ignition module, etc.
My dad’s 1960’s truck used to have this same problem. He installed something called an aftermarket capacitive discharge system on it, and after that every time it would rain or snow he’d have to get out of the truck, pop the hood, and turn off the cds. I never really understoon why he didn’t just remove the cds, b/c the truck ran fine without it. But my job was not to ask questions … lol …
See if you have any stored fault codes. They just might point you in the direction of what’s become moisture sensitive.
Post back with whatever codes you might find.
Appears it is losing it’s focus! Sorry. I couldn’t resist.
Two points off for missing capitalization. There goes your A+!
Thanks for the suggestions. As far as trouble codes, it has never thrown any. Ever. Would there be a code stored if it’s never shown one? How do I see if any are stored?
Spray coils with water and look for sparks.
Yes, there could be a pending code in ECM memory.