Eurovan 92 with gas engine and automatic transmission.
The engine starts fine and is also working fine at higher rpm, whatever the speed or the load. However, when idling, the engine seems to be misfiring/missing, not very much at first but getting worse if it is left idling for a few more minutes. It does not seem to be as bad when the engine is cold, like when first started in the morning.
Distributor cap, finger, spark plug wires were changed last year. Fuel pump and fuel filter were also changed last year. I have installed new spark plugs a couple weeks ago and a brand new Idle Control Valve a few days ago. TB was cleaned yesterday.
Idle speed on the tach is OK.
Any ideas/suggestions about what could be the cause of this problem would be much appreciated.