1987 Accord LX carb'd 2.0L w/AT.

Runs perfect until engine temperature is reached.While at road idle or accelerating, the vehicle runs smooth while below operating temp.The second the engine reaches normal operating temp the engine will give a little jerk/buck. From then on when accelerating, the enginefeels as though it is starved for fuel OR there is inadequate spark advance at distributor. At road idle it will give a little burp or stumble slightly occasionally. As though a control valve operates, when it warms up, causing a vacuum problem?

What do you think?

 

On the distributor there are 2 diaphrams, one of them is the cold start advance, the other is the advance for normal operation.
You can manually test them to see if one of them will not hold vacum.
I will recommend you take the vacum lines loose from the metal line when testing, the plastic nipple on the vacum advance is easily broken.
Also the hot air door diaphram on the breather snorkle needs to be checked.

If you can't find any problems with the diaphrams repost.