Backfire/pre-detonation

[Dan Owens]

Okay Guys,

I've been running the car to burn off the extra oil that was sucked into the engine and have had great success. Also still breaking in the engine from the rebuild. Actually once the airflow meter was replaced the thing has run like a champ until this morning. It ran great still a bit of a rough idle and a little low on the RPM's but okay. Ran strong in higher RPM's but just before shutting it off It backfired once and cut out. I had reved it up to about 3500 RPM's and it was coming back down by itself and then backfired and died. It now starts but has a pre-detonation (lack of a better description) into the intake plenum but only on one side. No knocks or smoke but just a strong ping inside the plenum like it's getting spark inside the intake. Not on every stroke but frequent. I listened real close and it's definitely only on one side of the engine and the plenum gets hot from the detonations. Any suggestions or ideas? This is an '84 with motronic. New caps and wires and rotor. New plugs, new DME relay, new airflow meter, new fuel filter, rebuilt engine. Any chance the timing speed sensor or refernce sensor came loose and needs to be adjusted? Any other ideas?

Dan O