Lotta pingin, 82 CFI
Thread Starter
Burning Brakes
Joined: Mar 2010
Posts: 943
Likes: 15
From: Valdosta Georgia
Lotta pingin, 82 CFI
Its about to drive me nuts. I've verified that timing is set to factory, replaced the temp and knock sensors, tried 93 octane fuel, nothing gets rid of it. Anyone have any ideas? What else could it be? I'm at a loss here, the only mod done on the car is long tube headers and dual exhaust, and I added a heated 02 sensor, all the A.I.R stuff is gone.
Le Mans Master
Joined: Apr 2001
Posts: 5,000
Likes: 1
From: Minneapolis, Mn USA
What is your base timing set to? and was it done with the EST wire disconnected, so the ECM is out of the circuit? Although if was not disconnected, your ECM would have been further advancing it, so your 6 degree BTDC setting would be retarded as a base setting.
How clean was your knock sensor connector? If it's gummed up with grease-grime, it will not read the knock signal.
What plugs are you using? I tried Bosch and ended up going back to the proper AC Delco plug part for a smoother running motor and I believe less knock.
Just a few thoughts.
How clean was your knock sensor connector? If it's gummed up with grease-grime, it will not read the knock signal.
What plugs are you using? I tried Bosch and ended up going back to the proper AC Delco plug part for a smoother running motor and I believe less knock.
Just a few thoughts.
Thread Starter
Burning Brakes
Joined: Mar 2010
Posts: 943
Likes: 15
From: Valdosta Georgia
Timing was set with the wire disconnected, stock 6 btdc, plugs are AC Delco RTS-45's gapped at .45, knock sensor wire was toast, had to be replaced, used an 87 as recommended on this forum, along with the 87 sensor,none of this changed anything, even knocks with 93 octane in the tank. Also, I noticed the exhaust note changes as the engine warms up. Goes from a great deep rumble to a higher pitch, so I'm wondering if I'm going lean
Last edited by Drawmain; Oct 10, 2010 at 07:41 PM. Reason: clarification
Le Mans Master
Joined: Apr 2001
Posts: 5,000
Likes: 1
From: Minneapolis, Mn USA
How is your fuel pressure? I suggest the 85 TPI pump mod EP241 to keep your fuel pressure up with higher injector duty cycle. The CFI pump is marginal when new.
This may be a source of a lean condition.
This may be a source of a lean condition.
