Hunting @ 2-2300 revs

[fordy]

I have a 1989 3.2 Carrera can someone help

when I am driving my car at a steady pace any speed in the 2000 to 2300 rev range the car starts to surge ( hunt ) violently only way to stop it is to change down to put the rev`s up

Have changed a few things , Air flow meter ( off my 964 ) new idle speed adjuster valve, new leads distributor cap & arm , had injectors cleaned the other year
not sure what more it could be

[fordy]

Now all sorted changed the throttle position switch, the new one had a higher resistor reading than the old one, Found the connections on the low tension side of the coil where movable so cleaned and tightened, found a bit of corrosion on both the inline plugs to DME relay & altitude unit cleaned them
Cleaned all other electrical plugs in engine bay
I bought a pair of crankshaft position sensor I was told it may be them but have not fitted them yet, getting fitted next week at the service
Now a joy to drive I can drive the car at the speed limit (30) without having to be in 2nd or 3rd gear to keep the revs up

[stlrj]

I'm still dying to find out which one caused the problem?

[fordy]

Stlry I am not too worried which one it was it only cost me £49 for the throttle switch and a few hour of my time, it could have been a combination of a few with small resistance’s on all of them as I found with the throttle switch
I talked to Charles Marsland register secretary of the 3.2 in the PCGB he had driven a lot of 3.2 cars and most of them had this fault in some way he said that he had changed a lot of sensors and parts on his car and slowly removed the fault but its still there to some degree, So I think it’s just a combination of the car getting old with old connections