I've done a quick search to see if i can find an answer but i can't seem to find anybody that has had the same problem.
I have a NA fc and when i start it up from cold after i've knocked off the fast idle the car revs itself constantly between 1000 rpm and 1500 rpm as it gets warmer it gets a bit better but when its fully warm the revs will be going up and down between 400 rpm and 700 rpm and sometimes it cuts off because the revs are so low. Not very often though.
But even when im driving it at a constant speed i can still feel it doing it which is my main issue with the problem. The power drops off and then comes back and it makes it very annoying to drive at slow speeds.
Its almost like the fuel cuts off for a second and then comes back.
Has anybody else ever had a similar problem? or know what the problem might be?

 

Watch this video and tell me if its the same.

 

Probably a TPS issue. Set the Green/Red wire of the TPS to 1 volt w/key to on after the car has been driven for about 20 minutes so as to totally warm up the engine, which is required in setting this sensor.

 

I think I'm having Same issue as OP.........what do you mean by "set" TPS to 1 volt?

 

Measure the DC voltage of the wire as stated. What reading do you get? If it is not 1 volt then you adjust the TPS adjustment screw until it reads 1 volt.

 

I just went out and checked mine and i squeezed every pipe that comes off the sensor and it didn't make any difference to the idle.
I'll have a go at adjusting the tps sensor tomorrow.
Thanks for the advice

 

Thanks will try....

sorry for thread jack

Good luck OP

 

Might be a dirty air flow meter also if it uses one of those.

 

Found the problem yet?

 

know what else causes this problem? vacuum leaks. These cars have a tendency to bake their hoses till their hard and brittle. They crack and play havoc with issues like this. Set the tps as prescribed. If that doesn't help, try taking Carb cleaner and spraying around the intake system while the car runs and keep an ear out for the idle to bump up. For example, if you blast a little under the manifold and the car idles higher, get ready to pull the manifold.

 

Any luck with this problem OP?