Ford Muscle Cars Tech Forum banner
1 - 2 of 2 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter · #1 ·
Hi I am trying to tune a holley 650 dp, which I recently bought used, with 2 oxygen sensors, one after each header collector. When I check wide open throttle the left sensor consistently reads about 1 AFR ratio leaner (13.4-13.8 mostly) than the right (12.3-12.6). At idle and part throttle (primaries only) the readings are even. I have tried spraying all the secondary passages with carb cleaner with no change. My Edelbrock carb gave even readings across the board. The engine is a 302 with ported heads, cam has 228 duration at 0.050. I spoke to holley tech support and the rep thought this was normal. Does this seem right? Any suggestions on other things to check or change? Thanks.
 

·
Registered
Joined
·
3,080 Posts
What intake? What do the spark plugs look like? It is weird that the readings would change when only the carb was changed. On a split intake each side of the carb feeds both sides of the engine, 2 and 2, so it really shouldn't be at the carb. Swap the O2 sensors side to side and see if the readings follow the the sensors, or stay the same. That will help you narrow things down.
 
  • Like
Reactions: cuthrell
1 - 2 of 2 Posts
Top