Strange Misfire / Speedo Failure - Linked?

[Davidkent]

As above,

I've a Mk1.5 1.8 Zetec Model on a 51 plate.

Its always had a very slight misfire type thing on idle, but its never bothered me, its done 142k but everything else is okay so far.

However, on occasion, my speedometer (Just the speedo) Drops to Zero, and comes back within a few minutes, occasionally its longer and all the numbers go to dashes - However, when the speedo drops, i feel an almost instantaneous power loss - Its nothing drastic, though causes a more severe misfire and stalling on approach to junctions and stops etc etc.

Are these problems likely linked, and what could they be?

The car had a new speedo Cluster from Main dealer in 2008, followed 300 miles later by a speed sensor.

Also, i'm unsure as to whether this is related, but when i change gear, or put my foot down on the clutch, the revs stick higher before dropping down again - I've been told this is common when the clutches near the end of their lives, and this could be the case, as to my knowledge, the clutch is original - Is this likely the case with this too?

Its still returning a healthy 35MPG on Combined driving, so i don't feel these problems are anything to worry about, just something i'd like to fix.

It was also serviced last weekend with Genuine Ford Plugs, oil Fuel and Air filters, Pollen filter etc

Any help much appreciated

David

[artscot79]

sounds like the vehicle speed sensor best get a garage to do it as its a pig of a job

[Davidkent]

I can do the job, but seems odd that it'd need another one - Box off soon for the clutch anyway, probably 5k's time

Suppose its done 65k since, but didn't think that'd make it run funny however?

[Stoney871]

Definitely speed sensor, classic symptoms.

Had it on my old mk1.

May be worth checking your throttle position sensor too to cure the ragged running.

[artscot79]

the vss can cause misfires cause the car to cut out running issues hesitation as for the job its an easy job but the pin usualy breaks and makes a simple job a major job at 65k id have expected it to go anywhere from 60k to 100k very common

[Stoney871]

As it's gone twice also check the vss wiring for wear.

[DJ_Andy_M]

My old MK1.5 had the speedo issue. Common Focus problem from that age of model.

You'll also find that if you have to stop with the speedo not working, the car will stall.

[Davidkent]

Yeah i suffer all of these, as mentioned it was changed at 76k, approx 300 miles after the new speedo was fitted - Its covered almost 66k on the new speedo and here's the problem again, so that may well be it.

Any idea of the part number and a decent place to buy the genuine part online? I don'd do ford dealers - Will obviously replace the pin at the same time.

Thanks

[martync]

had that problem for months and ive just changed the speed sensor today the speedo is now reading and the car is running smoothly again but the speedo dial has a little twitch ie will move up and down a centimetre or so from the correct speed every now and then,it has been fitted correctly,maybe there is something else that assists the speedo ?,spent an hour trying to get the bleeding thing out as well