Alright here's the deal. I usually use 87 octane with my car and when the engines cold, I can notice some detonation but once it warms up it goes away. I tried a few tanks of 89 and it doesn't detonate but I have noticably less power when I use 89....HELP?

------------------
1983 Z-28
305 LU5 V8(Cross-fire Injection)
Radical Cam
Limited Slip Differential w/
3.23 Gears
700R4
T-Tops
Pics-- http://www14.brinkster.com/ctrwsz28/

 

no thoughts guys?

[This message has been edited by CtRw (edited August 30, 2002).]

 

Only thing that comes to mind is ignition timing....

 

and how would I mess with this?

 

Try a couple of tanks of premium. Maybe you have 89 Octane that uses ethanol or some lame *** environmental chemical. Bunch of people told me that in Miluwaukee area, they use some sort of Oxygenated fuel that makes some people sick and screws up the power levels in the car. Actually try some race gas and if it still knocks, change the oil to the thickest stuff you can find and if it goes away, you may need a new engine.

 

Our 89 does have ethanol in it now that I think about it. I doubt I need a new engine... only 57,000 original on it. I'll try some premium once.