Had to retard timing 5 degrees to stop ping?

[RSTarga]

Originally Posted by universeman

RSTarga, printed on the decklid label of mine is 5 BTDC not ATDC:



Mine was set to TDC with hoses disconnected, and it ran hot. I advanced it to 5 BTDC and it runs much cooler, and starts a little easier.

Thats good to know, some years were ATDC. Some 0, some 5 BTDC. Thats why you need to check the specs for the specific year, also check the marks on the pulley as those changed too.

[911SauCy]

I. AM. Sub'd. Going through this same issue.

My car is exhibiting the exact same symptoms. After crying in a corner, sucking my thumb for a week, I pulled my lower covers to inspect for broken head studs as I was originally convinced (from reading old threads) that was my issue.

I was relieved and perplexed to find all studs in good order.

In relation to responses in this thread in hopes to shed some light for OP, my car has:
-New Magnecor wires
-Distributor was rebuilt 8k ago
-CDI was rebuilt as it died last fall (wondering if an improperly rebuilt CDI Box could cause this?)
-New fuel filter
-New fuel accum


I'm going to pursue the clean out the carbon route now as I was fiddling with my own take at CIS tuning and it was a rich adventure for a while.

I was also chastised by a couple fellow Pelicans for running 87 in my car...will be 93 moving forward.

If Chevron and/or BG44K and 93 octane don't help I'll be headed to a local race shop for a dyno tune. Any excuse to hit the rollers

[pmead]

After a successful drive with the timing set at 2 degrees advance, I advanced it a little more to the proper spec of 5BTDC. I was careful to set the idle to 950 during the timing process. The car has no detonation and pulls hard. I am not sure how the previous owner set the timing but it must have been advanced quite a bit. I should have checked it befor just retarding it to get rid of the ping. When I got the car it idled fast 1100rpm. I think the base timing may have been set with the fast idle and the vacuum lines attached. That may explain to much advance. Tomorrow I will check system, control, and residual pressures to trouble shoot the hot start issue.

[911SauCy]

This is pretty interesting outcome as I was thinking mine could also be a timing issue, which I will check. The ping I'm getting is all over the RPM range under load. Not necessarily hard accel but even taking off from a stop.

I have had an issue with my timing going off spec by itself before, how, I've no idea.

However, my issue has been getting progressively worse over the last 600mi of driving. It didn't just randomly start one day.

I put Techron and 93 in the tank and took it to the beach for the weekend to get the fuel through it as a first step...we'll see.

[pmead]

I started another post about my problem. After I found out I have very high control pressures I believe that this along with the timing issue may have been causing my pinging. From what I understand the high control pressures can cause lean conditions.