I have a stock 99 4cyl accord 5spd with 60k miles, and it seems to be pinging on 87 octane fuel. Its summer time in South Florida, so its been hot out, but the manual says the car should be good for 86 octane or better. This is essentially an economy car so it should run on cheap gas under all conditions.

My only ideas are to use some kind of engine cleaner to remove any carbon deposits that may be in the combustion chamber, or reduce the base timing a degree or two. I'd rather not mess with the timing as the car is slow with the timing set where it is. Also, I see now reason why someone might have raised the timing before I bought it.

Any other ideas?

 

just use better gas. Not so much octane wise but brand wise. Is this the only time it has occured? Did you get a check engine light?

 

don't bother fooling with the timing. it's controlled by the computer and it's non-adjustable

run some sort of engien cleaner through it and see if that fixes it. otherwise try a different brand or grade of gas.

 

its a common problem with the accords...i had/have it on both my accords. the best gas i use for it is 89. anything higher doesnt seem to do the trick, oddly enough, only 89. anyway, its expensive, so i only usually put it in for autocrosses and i dont bring it up to high rpms under normal conditions.

 

Just put in 89.

 

Its not a matter of rpm, its a function of load. Detonation is most likely to occur near the torque peak, I get it in the 3500-4500rpm range at full throttle, it goes away above that.

Using higher octane fuel is a band-aid, not a solution. I'd like to determine what the problem is and fix it rather than mask the problem. A base 4cyl car should have plenty of margin for fuel octane.

Can't you usually adjust the base timing, and the computer adds timing based on its maps to base? I know in other hondas you can put a jumper in the harness that allows you to re-set the base timing.

This is more of a problem for me when I tow my boat or go-kart with the higher load, so I would like to find a real fix for it.

 

In the helms manual it says that ignition timing is not adjustable, if ignition timing is off, replace the ECU. typically if there is any way to reset or adjust something, it is mentioned.

i agree that it's best to look for the underlying cause. I'd run a fuel system cleaner through it. carbon build up is an easy way to get detionation, especially in the conditions you describe

 

Your keyboard is stuck

 

Ahem {clearing throat}
Agreed

 

93 octttttttttttttttttttttttttttttttttttttttttttttttt ttttttttttttttt