Percolation? Heat soak? Don't drive during summer??

AJ/FormS said
Next time your engine is cold, in the morning; immediately after it fires up, just start cranking in some timing, until the engine rpm stops increasing. Now read the timing. What you see there is the correct amount of idle-timing for whatever the rpm rose up to. I'll guess you will see hi 30s to mid 40s. So even if your idle-timing is set to 18*, it is less than half of what the cold engine wants. And so, that is where the lightweight VOCs come in handy..

this is a test to verify what I earlier said, about all non-EFI cars being handicapped with retarded Idle-Timing, of necessity.

Put a scanner on your EFI car, and see how it is programmed..

I mean your other car, the one you normally drive,lol. Or your wife's car, or Mum's, any EFI car,lol. You will see how much cold timing the factory dials into them, so you can have a super nice drive-away.