So, assuming all else is well with an engine (94 F22B2 sohc accord lx) how would one elminate acceleration pinging? My ignition system is fine, I just did a carbon blow with some seafoam, and everything else seems fine... Looking down the spark plug tubes into the combustion chamber, there are still some little bits of black on the top of the cylinder, but its much better than before where it was all black with carbon.

so, should I carbon blow again?
Retard the timing even though its within limits?
richen the mixture a bit? (how?)
Could the ICV or FICV have anything to do with this if they were going bad?

thanks!
sohc

 

Knock sensor, mounted on the side of the engine block.

P

 

Actually, being I have a 94 F series, I have no knock sensor.

anyone else?

sohc

 

retard timing, about 4-6 degrees , also try the highest octane fuel

 

how do you know it's detonating?

higher grade fuel should resolve any detonation, but your accord should run just fine on 87.

are you sure the ignition timing is set right?

 

yep, being completely stock aside from a possibly leak in the exhaust (behind the cat) I have patched any rusty areas I can find. sometimes I get a "light pop" like tut...tut... which I assume is the exhaust leak, but could that cause the ping? it would seem the ecu would automatically adjust mixture to compensate??

I just adjusted idle speed and checked timing like 3 times in a row, and it is exact, except for my idle which will be 750 like it should, and then sometimes be at 1100, or 500 at idle, probably from a bad ICV.

I even went on a few test drives witht he timing retarded about 5 degrees, and once with it as far as I could go, but then it wouldnt stay running. It might have ran better at -5 degrees but I could still hear a "pinging" when accelerating. not loud, but noticable.

So, what is it?
Exhaust?
ICV?
It shouldnt need anything but 87!

Also, would it be bad to replace my exhaust from resonator back with a 127 dollar one from napa, or go with a honda one?

thanks all!
sohc

so now timing is once again back to exactly perfect

 

I'm willing to bet the sound you're hearing is not the engine pinging. Maybe the sound you're hearing is due to the exhaust leak?

A stock accord will not detonate for no reason. Is your cam and crank timing synched correctly?

How do your spark plugs look?

 

It has brand new NGKs (brass) and it still does it. the old ones only were about a year old and had a bit of black around the rim with a greyish L-arm until the tip above the electrode where it was whitish. no oil/deterioration or anything else on them. stock cap + rotor with some 1/2 year old bosch ultra premium wires, all conections have di-electric grease.

The sound is a tap/ping that is most noticable when in town between 1500-3000+ rpm when you "touch the gas" to accelerate even the slightest bit. if you let off enough to just maintain speed the sound stops and you just hear the hum of the engine. Some times if I accelerate briefly in town and let off slowely, the sound sort of expands like its echoing in a can or barrel.

If I do take it back 5 degrees and take a long trip is there a chance of screwing things up/ clogging the cat with unburnt fuel, fouling everyhting because its running too rich? or will the ecu compensate?

When I did a valve adjustment two days ago the up mark on the cam sprocket pointed exactly to the mark on the belt cover when the crank pully was exactly on TDC, so I assume that my belt and everything are in the correct position. Is there something else? and yes the dizzy pointed to the number one cylinder.

Im not sure how the exhaust could be making such a racket from the engine bay, unles it is pinging from being lean.

One thing, even though my valves are correctly adjusted, I have talked about this to my dealer before and they said a tapping engine was normal for the f22b2, but this doesnt really seem like a case of valve tick does it?

sorry for droaning on, I just want to fix this.

sohc

 

bump

 

i would say try to use seafoam again, maybe there is still excessive carbon buildup that you cant see and did not remove with the first session...