After tuning part and WOT, I'm attempting to fine-tune idle in a 427 cu. inch '01 Z06 with Lucas 42 lb/hr (@3bar) injectors. The car idles fine up to operating temperature from a cold start (see DH8a.hpl), but will not idle when started with a warm ECT (see DH8b.hpl). The attached data was taken with closed loop control disabled (ECT = 284F). The RussK idle config histogram to determine RAF is #8. The current .hpt file also uses the stock (78mm) ECT Area Scalar = 0.0255 despite the car having a 90mm TB (s/b 0.0186-0.0191) installed.
Can someone explain why the car idles fine from a cold start and then stalls at the same operating condition under hot-start conditions? Why is this????
And despite searching extensively on this forum and elsewhere, I've yet to find a good description of how adaptive idle control works. If someone can provide a link I'd be very appreciative. Could the stock Z06 settings for the Max (or Min) InGear/ACOff adaptive idle parameters be causing the hot start problem given that the engine needs a greater volume of air when the engine is hot?
Has someone compiled a list of items that should be changed when increasing displacement?
Thanks in advance for any help.
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