My '04 Ford Focus runs funny when it's humid. This is consistent enough to be somewhat predictable. Specifically, it tends to run rough, jerky, and loses a lot of power when going uphill or suddenly accelerating from low speed to high speed. What's the issue? Is this fixable? Anybody got any thoughts?
Posted by aspectre (Member # 2222) on :
Once upon a time, the first thing ya'd check for woulda been a cracked distributor cap. Assuming the exhaust wasn't smoking. Nowadays there's too much electronics feeding back into each other.
From your mention of the car's age and of a problem exacerbated by humidity, I'd suspect DPFE*Sensor failure.
While the workaround might be useful in diagnosing your problem, DO NOT operate your car in that condition. You WILL pay for such abuse, heavily.
If you aren't an amateur mechanic with a strong car hobbyist background, don't even try the workaround. Too easy to really gum up the works, and end up having to shell out a LOT of bucks to repair what wasn't broken before ya decided to tinker. Cheaper to just replace the DPFE sensor than to mess up an experiment. From the looks of things, you'll only be replacing something that'll need to be fixed sooner or later anyways.
* DPFE stands for DifferentialPressureFeedback for EGR
[ November 24, 2007, 04:02 PM: Message edited by: aspectre ]
Posted by steven (Member # 8099) on :
I don't see how DPFE sensor failure accounts for the fact that humidity makes the problem much worse.
Posted by Jon Boy (Member # 4284) on :
My first thought was bad plug wires. If I remember right, it's fairly easy to test for, too. Get a spray bottle of water, start the car, and pop the hood. Spray a couple of times over the plug wires, and if they arc, you know they're bad and need to be replaced.
Posted by aspectre (Member # 2222) on :
Sounds like a way to get one HELLUVA shock, possibly heart-stopping. Have you tried it?
DPFE and moisture. High humidity condenses into moisture as the air containing it cools: eg hot showers and bathroom mirrors.
[ November 24, 2007, 02:08 PM: Message edited by: aspectre ]
Posted by steven (Member # 8099) on :
Here's what happened. On Tuesday, I left the lights/radio on most of the day by accident, and it needed a jump. When we finally got it jumped off, we could see blue sparks jumping out all around the wire leading into the engine block, I guess where the spark plug is. When I saw those blue sparks, I know Jon Boy had been right.
It cost me $150 (fuel filter and air filter needed replacing too), but it runs better now. Posted by Jon Boy (Member # 4284) on :
I'm glad you figured it out and that it wasn't too expensive of a fix.
![[Dont Know]](graemlins/dontknow.gif)
there's too much electronics feeding back into each other. ![[Smile]](smile.gif)