I recently had the throttle body cleaned in my 1995 Bonneville. Ever since this had been done the engine idles rough and even stalls when it is cold. It does run better when driving the car now, but I did not have the bad idle before this cleaning was done.

The problem is likely a vacuum leak. Spray carb cleaner around the gasket on the throttle body and all vacuum lines. Listen for changes in idle.

I forgot to add that when you first start the car it revs for a few seconds and then almost stalls.

I was having the same problem after my motor swap and I put a different vacuum setupand it runs so much smoother, think I missed one but it doesnt jerk like it used to. So deffinately a vacuum line.

I have checked all vacuum lines and they are good. New IAC valve and EGR. Just replaced exhaust gasket that was leaking badly just below oxygen sensor.
When I start the car I get a very high idle for a few seconds and then it returns to a very low rough idle, although it will then jump to a normal idle for a few seconds and the back to a rough idle. It does this continuously almost like your flicking a switch. The overall engine performance is ok, but it has sluggish areas during acceleration that it had before throttle body was cleaned.
Thanks Fred

I have checked all vacuum lines and they are good. New IAC valve and EGR. Just replaced exhaust gasket that was leaking badly just below oxygen sensor.
When I start the car I get a very high idle for a few seconds and then it returns to a very low rough idle, although it will then jump to a normal idle for a few seconds and the back to a rough idle. It does this continuously almost like your flicking a switch. The overall engine performance is ok, but it has sluggish areas during acceleration that it had before throttle body was cleaned.
Thanks Fred

Have you checked the PCV valve?

Just had that out yesterday, it had a very little bit of sludge on it but it did rattle and i cleaned it and put it back in.

Did it have a O ring and a spring?