I finished my complete engine rebuild a month ago. Started up adjusted timing and she ran nicely. After the break in drives per Wayne's book she started to miss under load around 2000 rpm but ran great above and below that. I thought maybe old gas from sitting during rebuild so put in sea foam, a full tank of premium and she seemed to run better but still some missing. Parked it for one week and today when I tried to start there was a massive backfire that knocked the air cleaner off. Only a few backfires before.
So now it will turnover and fire/backfire and twice the engine revved high without my foot on the gas. Like a demon was back there.
Notes:
SSI installed but no O2 sensor PO did not have it connected. I was going to put one in but The SSIs bung was not standard so I plugged it. At idle she searches so I assumed it is a little rich.
All new wires, cap and rotor. Original coil, cleaned up the distributor advance mechanism.
One issue is the 12 pin connector has a broken end for the brown wire. I could not find a replacement so I pushed the pin in to the receiver. I rechecked this also.
I have the CIS gauges but have not used them as I am new to this system. Need to learn. And will do later today.
Your help is very much appreciated.
I will post some pictures
