- Local time
- 9:58 AM
- Nov 12, 2019
- Reaction score
It is either a lack of fuel or too much air, maybe disconnect and plug the PCV for now to eliminate it.
If you have rectified the root cause you can put it back on again.
Since it is just on idle circuit it does not have anything to do with jetting or power valves so no point checking that out.
I know my car needs a rich fuel mixture for idle, you can try fatten it up to 12.5 AFR and see what happens as you mentioned when increasing just a slight amount of more throttle the lean spot disappears which makes me think your transition slot starts feeding at that point.
This would indicate the idle circuit is ok to idle but not feeding enough to get going until the transition slot gets active.
I plugged the pcv completely and then it got harder to start the car.
I tried to fatten up the mix and also raised the curb a bit.
Its boiling down to ign timing or manifold leak.