D-jet masters question/help needed, very low idle/stall when motor is hot Options

[DRPHIL914]

I think this has been getting slowly worse but I dont really run the car for a long drives around here and its been cold too, but yesterday during a longer drive to a PCA event, on my way back having a lot of stop and go traffic after the motor had warmed up and reached full operational temperatures, my idle was dropping below normal , about 500-600, and after stopping for gas and sitting for about 10 minutes idle was normal (1000rpm)

Motor is 2056 with d-jet, with ignition 123 distributor.
fuel pressure is perfect, timing etc all good. all sensors were put in new when this motor was built 3-4 years ago. and i have always left the idle about 1100-1200 due to the fact that when it was fully hot it would come tdownt o 850-900 but never wanted to stall.

My thought is that the CHT is acting up and the resistance must be too high hot and now is sending a signal making it just like normal d-jet would get heat sink if a hot motor sat for a short time then wouldnt start. - is that a lean or rich condition that happens i cant remember but looking for your ideas thoughts here.

Phil

[JeffBowlsby]

Here is another thought.

Maybe the 'below normal 500-600' is actually normal - what the air bleed screw is actually calibrated to. When idle later increased to 1000, it was really reacting to a free air leak. If this is true, then you might look for a small air leak allowing free air in, somewhere in the intake system. Suggest using a smoke pencil to explore.

[DRPHIL914]

Here is another thought.

Maybe the 'below normal 500-600' is actually normal - what the air bleed screw is actually calibrated to. When idle later increased to 1000, it was really reacting to a free air leak. If this is true, then you might look for a small air leak allowing free air in, somewhere in the intake system. Suggest using a smoke pencil to explore.

Jeff, i suppose this is a possibility, so i can recheck these areas, motor has been together for a couple years and about 5,000 miles. Tuning as you know, on a 2056 using d-jet can be a challenge but it has been running really well, It was on a dyno a few months back and at that time the AF used by them showed it pretty much where we want it for mixture until about 4800rpm then from there to 5500 it gets lean but at a cruzing rpm and part load it was perfect. hwoever certainly i can make sure i dont have a leak.

but since the beginning with this motor with all new seals etc its always required a bit more air at idle with the idle air screw partly open , it is timed correctly , no vac canister on the 123 distributor is hooked up no not having the vac retard on, but even with out this the idle would be very low. I am also going to recheck timing again but with the 123 the last 3 times i checked, it was spot on.
If i had an air leak wouldnt you suspect that the idlw would be too high not low at temp?