Over-revving boxer 1.7 16v.

[Major_Day]

The problem i'm having is this: The problem arises when i am on the motorway driving between 60-70, it feels like the throttle is jammed,(although the pedal is free to move) i can lift my foot off and the car will happily carry on at the same speed, at about 3500 revs, when i come off the m/way and try to slow down by changing gear or slipping her into neutral and braking, the revs shoot up to 4000,and stay there.
Immediately switching the engine off and on again makes no difference.
Once i start driving again and make my way up through the gears (at 4000 revs) i can let the engine load drag the revs down to normal, after which everything seems ok (around town that is)
I have checked the throttle cable,linkages and butterflies,and everything is free.
This happens first thing in the morning from cold,so im wondering if its temp. related, i changed the maf for a spare one i had, but it made no difference.
Throttle sensor was renewed about 3yr ago,crank sensor,air temp. sensor, lambda were renewed last year.

I should point out that it only takes me 10 mins. to get to work in the morning via the m/way. but when i get to the traffic lights at the end of the slip road (leaving the motorway) the engine is stuck at 4000 revs.
This only started happening last week, so i'm kind of wary about taking her on a longer journey and revving over 4000, to see if the problem persists. (don't want to damage the engine)
Any ideas guys?

[Major_Day]

Sorted the problem out by doing an ecu reset, as described here:
Board Message

[96red-spider]

how do you re set the ecu i have a simular prob with mine

[Major_Day]

If you have a lumpy or high idle speed then the first thing to try is a throttle actuator reset:-

1. Switch on the ignition but don’t start the engine and leave for 90 seconds.
2. Switch off the ignition and leave for 90 seconds.
3. Start the engine without touching the accelerator.
4. Leave engine to idle for at least 10 minutes.
5. Switch the engine off and leave for a further 10 minutes before starting the car again.
6. Take the car for a spin and make sure you drive it in different styles including hard!
7. The idle should now be back to normal. If not continue with steps 7-9.
   
   Optional: ECU Reset (clears some of the stored ECU parameters):-
8. Disconnect the battery for at least 45 minutes (make sure you have a record of any stereo security codes).
9. Reconnect the battery.
10. Repeat steps 1-6 again.

NOTE: The 90 second period is quite critical so use a stopwatch. If you are over or under by just a small amount the procedure won't work and you will have to start from the beginning again. This means that it sometimes takes a few goes to get it right.