86 Pinging
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,234
Likes: 5
From: Herriman UT
86 Pinging
Just completed the last of the top end mods which was the installation of large tube runners and ported plenum. Since this last mod I developed a slight pinging on hard acceleration during hot weather after full warm up over quite a wide RPM range. No pinging prior even using mid grade unleaded (running premium now). Timing is set at 6 deg & have new EGR valve & everthing else up top. Do I need some work on the chip due to the latest additions? Any ideas?
Current mods; Cam, heads, headers, Big Mouth manifold, LT runners, ported plenum, Stage V chip, 52mm TB, etc.
Current mods; Cam, heads, headers, Big Mouth manifold, LT runners, ported plenum, Stage V chip, 52mm TB, etc.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 32
From: The Top of Utah
Lean mixtures run hotter and are more likely to detonate. It sounds as though your intake mods have added air and not fuel, making the mixture leaner than before. If so, you are going to need a chip update to get the A/F ratio back in line.
I don't know why the O2 wouldn't compensate. Are you running in closed loop?
RACE ON!!!
I don't know why the O2 wouldn't compensate. Are you running in closed loop?
RACE ON!!!
Drifting
Joined: May 2003
Posts: 1,730
Likes: 1
From: Charlotte NC
St. Jude Donor '05
Do you happen to have a chip in the car now? If so I would go back to factory and contact the makers of it.
Don't drive around with it detonating.. thats really horrible for the car.
Don't drive around with it detonating.. thats really horrible for the car.
Safety Car
Joined: Sep 2001
Posts: 4,134
Likes: 531
From: Glenbeulah Wi
Check your knock retard system. I also have a 1986 vette and I was experiencing ping at WOT with no knock retard on the scanner. The knock control module had failed and it did not set an error code. I replaced the module and the pinging went away.
