Hello, all. I recently converted from TBI to TPI and have been chasing a gremlin(not the car) ever since. When I use a timing light I notice very eratic/unstable strobes while observing the timing mark either with or without the distributor control mobule connected to the ECM. Shouldn't the strobes be steady while runnig on just the distributor module? The engine also takes about 5 minuets to get down to a proper idle. I have replaced the O2 sensor with a heated unit(headers) to no avail. Help.

 

I had it happen to me the other day. Absolutly make sure you have the ecm disconnected and not the tach.

 

bad timing chain could do that

 

bad timing light, as well.