ok, so i had a z6, for a year i ran premium(93) gas, then sold the turbo setup, ran 89 for about two weeks, engine blew(spun bearing). now i have the z6 head on the cx block... it had 89 in it(about half tank) that had been sitting for 1 1/2 weeks, and about 4 days old before the engine blew. it is spark knocking pretty bad since i started it... but only under acceleration, not when you are stopped reving it up.

i had about 1/4 tank left when i filled it with premium and put new plugs in it... it got a little better, but still doing it. any good way to fix it fast before it messes something up? i have about half tank in it right now. should i add some octane booster, or go to a local pump that sells 100 and put in a gallon of that? please help. thanks

 

if you want, pour 1 gal of toluene in the gas tank. can be had from your local paint store. will significantly boost octane.

octane booster doesn't do ****.

 

yea i know octane booster doesnt really help. but that pump that sells the 100 octane gas... i think that would help bring the level up a little. wouldnt it make it knock if the octane was too high? or would it just clean it out and run a little faster? thanks

 

or should i just go and keep the tank full all the time with 93 until it finally is all 93 and no more old gas...

or should i just let it run through the old stuff, then the whole tank will be clean and fresh. how dangerous is it? it isnt doing it very bad anymore, but it is still noticable if the window is down..... is it going to mess anything up? thanks once again

 

is your timing off? did you change it for the turbo setup

 

no, timing wasnt changed for turbo... but when i put the vtec head on my cx tuesday, i had the engine out of the car, set the crank timing notch at 0 by linning up the mark on the block with the one on the bottom timing gear? then turned the cam gear so the two marks lined up with the arrows, took off the dizzy cap to make sure it was pointing dead at #1, THEN put the head on the block, put the z6 belt on, tightened it all down......... THEN re-checked the marks on the bottom and at the cam gear... everything was perfect.....

only guess if cuz it was old nasty gas... and still some in the tank. just didnt know if i should stick out the spark knocking until it goes to E, then refil with premium, or if i should keep it full with premium and eventually the old gas will mix and be gone....or if i should put in a gallon of that 100 octane and let that bump the octane up...thanks for the help