pining

[sportbiker929]

pinging

timing is sent to spec, ND plugs, HEI dizzy, High flow exhaust and cat. What is making this thing ping? Lets say 45mph 3rd gear and I floor it and push the pedal down and it starts pinging. It happens at all speeds? Can mixture cause this? Coul my carb be out of whack?

Ideas??

Mitch

ps, running chevron regular

 

[djanis99]

I have the same problemm, I assume that it is from carbon buildup inside the cylinder. My fix is to use 89 octane instead of 87. I figure $2.00 everytime I fill up my truck is cheaper than a blown engine.

 

[Cruisergreg]

If you are desmogged or the EGR is otherwise not working you can get pinging even at correct timing settings. Also make sure your HAC isn't malfunctioing because device will advance your timing to 13 BTDC, which can cause a ping at low altitudes.

 

[sportbiker929]

to update, when its pinging, if I pull out the choke it stops pinging.

 

[NocalFJ60]

to update, when its pinging, if I pull out the choke it stops pinging.

Have you rebuilt your carb or has it been apart recently?

 

[sportbiker929]

Have you rebuilt your carb or has it been apart recently?

No idea

 

[svo_jon]

If adding more gas fixes the problem you may need to rebuild your carb. Or, said another way, yes fuel can affect ping. If your mixture is too lean the temps in the cumbstion chamber go up and this can cause pinging.
Another thought is that your timing curve may be too steep. My DUI distributer as delivered advanced the timing too much at higher rpms, the centrifugal advance needs to be limited a bit.
Just my two cence
Jonathan

 

[NocalFJ60]

Do you still have a stock distributor? How about put it back in and see if the problems continues.Do you have emissions testing? Did it pass fine?

 

[import silvia]

Pulling the choke results in a rich condition and would be expected to eliminate pinging, along with fuel enconomy and emmisions quality.

 

[sportbiker929]

Pulling the choke results in a rich condition and would be expected to eliminate pinging, along with fuel enconomy and emmisions quality.

I realize the affects of pulling the choke, just using it as a test. I am more curious if the free flowing exhaust is causing it run lean? I might try putting the OEM dizzy back in.

 

[beaufort-fj60]

check your knock sensor

 

[sportbiker929]

check your knock sensor

That's funny