Pinging on takeoff
- Thread starter Bonnewagon
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really could be a bunch of things. Easiest thing to check would be timing. Try blocking off all the vacuum variables and only plug the distributor ( no EGR, PCV, brake booster** ect ). I would suspect that in a car of this "vintage" that the distributor is getting worn or you have some slack in the timing chain ( which btw will run fine at idle and crap when under load ). If it still pings then you know it's likely either the chain or the distributor
** if you disconnect the booster leave lotsa room to stop when taking it for a test drive as you will have to stand on the brakes to get it to stop.
** if you disconnect the booster leave lotsa room to stop when taking it for a test drive as you will have to stand on the brakes to get it to stop.
Here's an update. Still pinged, but then a guy on Classical Pontiac suggested I was running the automatic trans advance system when I needed the manual trans one. He was correct. I found burried in the 77' Pontiac manual a sheet of specs and the correct vacuum routing for a manual trans 301. I needed to use straight ported vacuum for the advance and bump the initial timing up to 16 degrees. This cured allmost all the pinging. If I'm in too high a gear or start off at idle, it still pings. After this 'noreaster blows by I'm going to swap the EGR valve just to be sure.
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