Ok, so here's a little story. When, way back in April, I successfully broke an "A" cam and had to go back to my "M", the car idled fine, but would ping slightly under high load at lower RPM. The ping had not existed before the cam switching, but the car reved fine after...it was only under high load at lower RPMs after the whole ordeal. So I put in a "K" cam a few days ago, hoping that the pinging might leave. dumb idea. it still pings under hard accelleration. The thing is, i'm quite positive all the timing marks are aligned, especially since it idles and revs fine, so how the heck could I have gotten the timing off? I'm hoping it's just some easy thing i've missed...thanks a bunch!

nate gundy

Do you have any delay valves on the vacuum line to your ignition computer? Get rid of them - they screw with the timing for emissions purposes, but they end up causing ping more often than not. Make sure you don't have any vacuum leaks. And of course, check your base timing - should be 12deg +/-2, unless you've tweaked it.
--
Speed Racer, '83 240 R, '74 164 E, '93 940 OL1 (Manchester, CT)

Pinging almost always occurs when the spark is too far advanced relative to the engine speed and load.

Can you check the timing with a timing light?

Through 1988 the distrubutor could be turned a little to adjust timing. What year is your Volvo?

Good Luck,

Bob

:>)