Alright so ive had an on-going issue for a while now but i havnt driven the car in about 4 months due to several projects going on and being to busy. Well i finally got it back together and need to drive it to get my exhaust welded up so i can get it licensed again and get some plates.

Problem ive been having even before i put it on jackstands for a while is it feels and sounds like its mis-firing at idle. After the car warms up the exhaust will pop randomly and i can see the rpm barely fluctuate on the speedo. Its not a machine gun mis-fire or anything crazy, just 1 pop but it happens continually every 2 seconds give or take after the car is warmed up. When this is happening if i turn on my ac or heat to full blast the idle increases slightly and stays firm, it may happen every few minutes with the ac/heat on but as soon as i turn it off the popping starts immediately and usually does 2-5 in a row then slows down again......

I have a wideband but until i get the exhaust welded up i cant actually see what its at. Car was tuned a long while back and its been an issue ever sense. I tried taking it to a local tuner to check out the a/f but at the time he wasnt a hondata dealer and had no way of checking it other than with a sniffer which from what ive been told is hardly accurate or a way of properly measuring it. Car still runs its ***** off but once its at idle its very irritating. Last dyno 199whp/132tq

Set-up is

93 del sol
00 jdm itr swap
s200
440cc injectors
msd box, blaster coil, cap, rotor
lots of bolt on's
stock bottom end, stock head
s2s1 cam's

was thinking of getting another set of plugs but if memory serves it did it on the last set as well

thanks for the info guy's, i really appreciate your time and help

 

tried fresh plugs, and had them gapped at 45, also tried gapping them at 50, no luck

also raised the idle through the idle control screw on the throttle body, didnt help'

basically the only way to keep it from popping/mis firing at idle is to turn on acessory power such as the a/c system', then it is about 95% gone'

car gets dropped off for exhaust system wednesday, then hopefully tuned the following weekend', going to change injectors to bosch 1000's to insure its not an injector issue and give me plenty of room for the future set-up

 

Without wideband data, you are guessing at what the issue is....
My guess is your idle is lean, turning the a/c on causes your load values to change, causing the vehicle to idle off different fuel values.

 

do you have the tuner stage 1's or pro1's?

when he have higher than stock output motor. u gap the plugs tighter my friend not looser. that may be your reason. gapping too wide makes the spark have to "jump" a larger range and cant sufficiently burn the mixture. try .038-.032

 

stage 1's there slightly larger than itr's but not by much, msd says usuing there ignition the gap can be made larger, they reccomend gap of 50 how-ever the plugs that are currently installed at gapped at i believe .44 but there the wrong heat range "****ing hate o-reillys", ordered the right plugs today and cleaned up the rotor, external coil, checked the connections and so fourth

anywho i got the exhaust welded up and wideband installed but its mis-firing really bad now...car stutters and stammers badly on WOT, the a/f dipped as low as 8 on the wideband when it started to mis-fire...

i still havnt figured out if its a spark issue which is causing the mis-fire and causing the wideband to read rich because of the un-burnt fuel from the mis-firing or if its actually just running too rich and causing the misfiring issue

it ran great before on WOT just had partial throttle issues, but driving home from getting the exhaust done it felt like ****, huge loss in power, mis-firing anything WOT after 5k rpms...took it easy and coasted it home'

bosch 1000's and fresh tuning next week reguardless', just wanna make sure its not a spark mechanical issue before i pay for dyno time...pulled the old plugs today "wrong heat range" but the tips looked like a good burn', will know once i get the new plug's in...then ill make a couple wot pulls and see what the a/f is, if it dosnt mis-fire i should get a decent idea', not too worried about it, car's getting towed in a week to be re-tuned on the 1000's', ill get it figured out then worst case scenario