Here’s the problem.. My car has a slight missfire at idle. When the engine is first started from cold, it runs smoothly, no missfire, as it warms up it develops a missfire that practically disappears when fully warmed up @79c, although it is still there, it’s just a pop every now and then. I’ve heard other zeds doing the same at warm idle.. I asked questions, but the reply’s are the same.. cant find it, not sure. When my engine is free revved say to 2500rpm or held at a constant rpm, a slight missfire returns. The rpm drop to idle is also slow, when the car comes to a stop, any stop, foot of the throttle clutch in, the engine will high idle @ 900-950rpm before gradually returning normal idle 750-800 takes about 4-5 seconds, really annoying. When I accelerate the car in gear under hard or normal throttle, there is no missfire that I can here or feel, or see, on a logged graph.. consult datascan nistune. My first thoughts were Vacuum leak, so I started checking the normal things, did a BLT, found a tiny leak at one off the recirculation valves fixed that, started the engine same thing. Checked all the injectors the coil packs the spark plugs NGK PFR6B-11B which are new and gapped to 0.035" and firing. Moved onto the IACV, and air reg, no problems there either.. I should say that the air reg and the IACV have been internally (everything was dismantled including the air reg) cleaned to within an inch of there lives, and reinstalled with no change to idle. I new the Iacv and the air reg were good in the first place, because I could see both operating normally with consult, aac sits on 30% when up to temp, and can be manipulated up or down and make a difference using the program. I have twin maf’s selin setup, both mafs are Nissan ome and good, the tps is set at .46v and is also good. The engine is 3000 odd ks old from a top and bottom rebuild by joe imbesi, and is strong. So I pulled the plenum checked for any leaks round the gasket, nothing. Pulled the rails took them to asnew injector cleaning all good, checked all the vacuum lines while I was in there again, when it was back together I propaned tested the lot, nothing I could find sucked or leaked. Interestingly the stock boost gauge needle, at idle, sits pegged hard left, and the greedy controller shows vacuum at -99 which is as good as it gets.. So in reality I could possibly have saved myself the time of pulling most of the top of the engine apart and taken notice of the readings, but I had to be sure. So next I decided to do a compression test, and have as look at the bores with a endoscope.Warm Comp test showed even compression among the 6 pots varying by only a 4 psi peak was 180, the bores looked normal, piston tops were clean no burns, the battery was a little flat, so only one comp test was done. Did a vacuum test on the engine from the balance tube to get both sides, 20.5-21hg at idle, there was a tiny fast movement of .5hg @ idle smoothed out with any amount of throttle, I put this down to slight wear of the valve guides. The last thing I tried was the throttle bodies, they are pretty much set in perfect synchronization, and dialed in as per the manual. The tune I have is from czp by jim wolf for 16-18psi. So there you have it, another frustrated zedder.