hey guys well over the past while ive done some things on my car to try and get rid of a high rpm miss and spark retard that usually only occurs when i go wot or if im just cruising along and punch the gas.

i took all the plugs out and i noticed one that was loose i could move it with my hand. also i found a plug wire where inside the boot it was black and sooty. all the other ones were good. i figured this was my problem so i replaced the plugs with ngktr55 and taylor wires.

after changing those the car felt better and there was no longer a miss anywhere up through the rpm range. so that cleared up my high rpm miss but i still had the spark retard and the exact same amount in exact same spots.

everything ive changed so far:
fuel filter
lt4km
coil
injectors - had a leaky one, car worked a little better after this, better throttle response
plugs
plug wires
knock sensor
coil wire
ignition control module
egr valve

after all this i still have just as much knock as before. on some of my logs ive even noticed as much as 5-6degrees pulled right after i let off the gas.
most of the spark knock is still pulled at certain points on wot or near wot run.

i usually never see any knock above 5000rpm right up to 6000. its usually right in between 2500-4500 almost all the time.

now people have suggested me get higher octane gas to test out or xylene to increase octane but the highest octane we have around here is 91 or 92 and thats what i use all the time. people wont sell me xylene and no where to get any other higher octane gas. do u think if i just left a couple gallons of 92 octane gas in tank and added some octane boost that would do anything to increase octane?

does it sound more like false knock or real? if u think real what else could i check? the only thing ignition related at this point i can think of would be the opti but i have no symptoms of a bad opti unless its possible just to have dead spots or something.

sorry for the long post but damn this is annoying.

 

well i have a 94z and if i get on it full throttle i see upwards of 10 degrees of retard . but if i just cruise around i usually don't see any. it was usually random amounts of retard through the entire throttle. so far i put in an lt4km and had it tuned for my cam, but it still has retard. my brother had a 95 firehawk that would see up to 15 degrees of retard. i don't know if you can totally get rid of it. but it sounds like you're better of than me.