2002 Ford Focus - hesitates/surges with speedometer spiking

Please help me understand what is wrong with my car!

And thanks in advance to all you hardworking folks that help maintain this forum - a ton of great information here!

only owner, 2002 Ford Focus, ZX5, the bigger of two engine types, standard transmission, 70,000 miles, recent clutch replacement, 'check fuel cap' idiot light came on several weeks ago ... followed by check engine light a few weeks later.

I checked the computer codes, but the only one is for an emissions leak (check fuel cap light).

So, here is what it is doing... the car starts fine, but then stutters when I start moving. The problem seems to go away as engine rpm goes up (almost non-existent above 2500 rpm). I cleverly deduced that there must be some water in the gas line, or I need a new fuel filter (never changed). I guess I'm not that clever though. I bought a 'complete fuel system cleaner' additive and a water remover additive (alcohol), and dumped them in the tank. I bought a new filter, but haven't installed it yet. I'm about halfway through the tank with additives.

The stuttering happens in all gears at low rpm, but is most pronounced in first gear (and I think Reverse gear) under load ... like if I were to start moving from a red light on a hill.

Small jumps of the speedometer accompany the stutters. These speedometer jumps are typically no more than 3 to 4 mph changes, but they are sudden and spiky. Occassionally the spike is more pronounced. This morning, as I was pulling out onto the road in first gear at under 5 mph the car stuttered and I saw the speedometer briefly spike to around 60 mph.

It is this accompanying speedometer business that has me worried it is a more serious problem, but I don't know anything about where the speedometer gets its data or why it would jump like that.

Can you help me?

Wade I've been cogitating on this for awhile trying to make a connection between the spiking speedometer reading and the engine stuttering. I think maybe the speedometer fluctuations could be due to electrical interference because maybe the VSS line is too close to a spark plug wire. Maybe the stuttering is actually misfiring because of some kind of fault in the ignition system. But the engine idles smoothly and operates smoothly above about 2500 rpm. So what could cause misfiring only under load at low rpm?

The plugs and cables were replaced November 2008. But maybe the distributor cap was not replaced, or maybe there is a problem with the distributor/rotor. Could a poor connection on one of the cables cause these symptoms? Maybe I only need to check the cable connections for tightness/cleanliness. I can't check until tonight. Does my car even have a distributor?

Does anybody have any thoughts on this?

I wrote the fault code down, but don't have it with me. It was either P0442 or P0455. Does this sound like it could be related?

Any help or thoughts on this would be greatly appreciated.

Wade fought exact problem with daughters focus,found ignition coil cracked ,look for small arcing marks.and yes,speedo spiked Thank you so much for the response. That backs up my suspicions about a fault in the ignition system.

The problem is getting worse quickly, so I'm going to take it to a mechanic tomorrow. I can't spare the time to do the work myself right now, but at least I will go with some knowledge in my back pocket. I'll let you know what I find out. problem resolved.

Replacing the ignition coil fixed everything.

Thanks again - and I hope this thread helps someone in the future. Way to go p.hinds! I OWN A SHOP DOWN IN MEXICO AND I HAVE REPAIR THIS PROBLEM SEVERAL TIMES IN THIFERENT CARS FROM MY CUSTOMERS...THE PROBLEM IN ALL THE CASES WAS THE IGNITION COIL INTERNAL FAILURE...THIS FAILURE PRODUCES A HIGH MAGNETIC FIELD, AND THAT INTERFERENCE GOES IN TO WIRES OF THE VSS SIGNAL (VEHICLE SPEED SENSOR) THE Car Repair Talk's forum.