Pinging

[LannyL81]

The engine pings like crazy on acceleration. I set the timing according to the emissions lable....now what?
It's not overheating....
I've looked and all the vacuum lines are in place, no cracks seen...
New plugs and wires.....

Is it running lean somehow?

Thanks,
Lanny
St. Louis car
Tucson, AZ

 

[69_coupe]

Yes it might running lean, however your timing can still be wrong.
A common problem is that the springs for the weights are getting weak. This causes the timing to advance to early and the engine starts pinging.
An other problem, not that common, is that the outher part of the balancer is moving on the rubber band (crank balancer consist of two parts) this will cause the timing mark to be wrong. And of cause your spark plugs can be wrong.

Vidar

 

[vettenick]

Check that your EGR valve is working and or the passages are not blocked with carbon . If this valve doesn't work, your cylinder temperature will go above 2500 degrees and that will cause pinging. If you want to know how to test it, just ask.
Good luck!

 

[LannyL81]

Vidar,
Well I know for sure its not the weights causing the pinging....because there are none...this is an '81 remember...no weights...all controlled by the ECM.

As for the EGR, I will check it out tomorrow along with the balancer. I had a balancer separate on me once, so I know the problems that it can cause. Had not thought of it though.

Thanks,
LannyL81

 

[Tom Bryant]

Can also be excessive carbon buildup on the piston tops. Sharp edges of carbon are great places for hot spots that cause pinging. Might ask your technician about running GM Top Engine Cleaner through the engine as outlined on the can. It desolves the carbon. With the stock type bead cat convertor you need to seperate the convertor from the front pipe first so all of that carbon and junk doesn't clog up the convertor.

Tom