Ping monster has showed his ugly head!

[DZEE'S LX]

A couple weeks ago I noticed pinging. Thought it might be bad gas but a new tank now hasn't fixed it.
It has been hotter 90 - 100 deg but my car has never pinged during the summer for the last six years. Even after all my engine mods it has always been "pingless".
It is doing something else strange now. At full throttle and about 4500 rpm the engine suddenly pulls harder like an abrupt turbo boost, but at that same time the pinging starts and goes nuts. If I roll into the throttle gradually to wide open it doesn't seem to ping much.
It's almost like the timing jumps at 4500 which gives me more power but obviously is too much for the mid grade and 18 deg timing that I have always run.
Bumped the timing back to 15 and the pinging is still there at top end but the power surge at 4500 is not noticable now.

Is my distibutor the problem? What actually advances the timing as rpm increases. Still using the stock distributor.

I would blame it on hot weather and too much timing but it doesn't make sense that it has never done this BS before.

Please help this be a cheap fix!

Dan

[Capri306]

MAF sensor was the first thing to come to mind....

15°-18° BTDC seems like a bit much, honestly. 14° BTDC is more common, but it's still on the ragged edge for most motors. I usually ran 12° BTDC myself, to get out of the hole faster.

Spark plugs been changed lately?
Sure you're not losing fuel pressure?
Is the damper actually showing the correct timing?
How about the strength/color of the spark?
Has the TFI module been replaced?

[DZEE'S LX]

Thanks for the ideas.

Cleaned MAF recently when I was trying to get rid of my idle surge.

It isn't uncommon for people around here to run more timing because of our 4400 ft elevation. At least that's what I've been told, that you can run a few extra degrees at higher elevation.

Anyway I've been running the same 18 deg timing for years and years and never noticed pinging in the summer.

New 155 fuel pump wnet in at the beginning of the year. A/F ratio on the dyno seemed to show that pressure is adequate up through 6000 rpm.

TFI was replaced last year.

Plugs are in decent shape but they could probably use a change.

I guess I was thinking something was wrong with the timing advance since I get the power jump at the same time the pinging goes nuts.

Anyone know what mechanism/component advances timing?

Thanks,
Dan

[DZEE'S LX]

So I decided to replace the plugs with new 3924's so I can rule that out.
Now I'm at the classic gap question. Search this forum for the answer but there are many opinions. Stock is .054 but I'm leaning toward slightly smaller, like .048 to solve the ping problem. Also have stock ignition. Any opinions?

Also, this could be a stupid question, but I've always wondered why they include the ring in spark plug box. Is it optional? Do I use it with aluminum heads...?

[USMC302]

Use some antiseize with the aluminum heads, I run the same ones (plugs and heads). I would back off the timing until the pinging stops.

They could be deluting the gas trying to make it stretch a little since it costs so much now!! lol making you have to run premium. j/k