Pinging amd ac help
Thread Starter
ZR1TG
Joined: May 2005
Posts: 875
Likes: 235
From: South florida
Pinging amd ac help
Hey guys just picked up a 69 300hp auto with factory ac r -12
cant get the engine to stop pinging on acceleration .
Timing looks good at 36 degrees all in and 14 intitial. I tried retarding it to get rid of pinging and no luck. I tried adding lead substitute and octane booster no luck.
Car also runs too hot. Idles at 210 and if out ac on that jumps 20 degrees. Does not seem like ac cycles at all. Haven’t seen it shut off so not using it at this time but the ac blows very cold and is the reason I bought the car. When checking timing I did notice that the number one cylinder is not in the usual place on the
distributor. It’s one over and the timing mark seems to work out ok but can’t help if wonder if this has anything to do with the pinging. ? I also thought I would try a 160 thermostat to cool car off a bit but turns out it already had a 160. I put new one in anyway and of
course no difference. Very nice car. Frame off restored has orignal everything including smog pump but not running right and ac not working right either
Anyone have any thought or similar experience ?
Thanks guys !
cant get the engine to stop pinging on acceleration .
Timing looks good at 36 degrees all in and 14 intitial. I tried retarding it to get rid of pinging and no luck. I tried adding lead substitute and octane booster no luck.
Car also runs too hot. Idles at 210 and if out ac on that jumps 20 degrees. Does not seem like ac cycles at all. Haven’t seen it shut off so not using it at this time but the ac blows very cold and is the reason I bought the car. When checking timing I did notice that the number one cylinder is not in the usual place on the
distributor. It’s one over and the timing mark seems to work out ok but can’t help if wonder if this has anything to do with the pinging. ? I also thought I would try a 160 thermostat to cool car off a bit but turns out it already had a 160. I put new one in anyway and of
course no difference. Very nice car. Frame off restored has orignal everything including smog pump but not running right and ac not working right either
Anyone have any thought or similar experience ?
Thanks guys !
Melting Slicks
Joined: Feb 2017
Posts: 3,232
Likes: 1,232
From: PHX AZ
Dear Hard Hat...some general rules to follow and look at. (I have a 69 hence my screen name.)
1. Pre-detonation is caused by the following. A. Hi compression B Vacuum advance and or Mechanical advance. C. Carb out of stoichiometric LEAN. (vacuum leaks?)
2. Too much heat, get the car cooling! (I have a big block fan and big block max aggressive fan clutch.) SEAL THE RADIATOR with proper gaskets.
3. Carbon in the cylinders causing 'nucleation sites, that cause 'pinging'
4. Load...does the pinging occur only when the A/C is on?
5. Fuel...have you temporarily tried AVGAS? does the symptom go away?
6. COMPLETELY re time the car from SCRATCH! Wires off and re-do it right!
so...Timing, advance,heat, fuel, load, LEAN!
good luck.
Unkahal
1. Pre-detonation is caused by the following. A. Hi compression B Vacuum advance and or Mechanical advance. C. Carb out of stoichiometric LEAN. (vacuum leaks?)
2. Too much heat, get the car cooling! (I have a big block fan and big block max aggressive fan clutch.) SEAL THE RADIATOR with proper gaskets.
3. Carbon in the cylinders causing 'nucleation sites, that cause 'pinging'
4. Load...does the pinging occur only when the A/C is on?
5. Fuel...have you temporarily tried AVGAS? does the symptom go away?
6. COMPLETELY re time the car from SCRATCH! Wires off and re-do it right!
so...Timing, advance,heat, fuel, load, LEAN!
good luck.
Unkahal
Le Mans Master
Joined: Aug 2005
Posts: 6,541
Likes: 1,975
From: Temple Terrace Florida
Is it possible that your 50 year old damper has slipped? You can check for top dead center in the #1 cylinder with the spark plug out when the engine is coming up for compression. At that sweet spot, your timing mark should be aligned at the timing mark on your tab. Jerry
