Backfire during Idle
Thread Starter
1st Gear
Joined: Sep 2016
Posts: 1
Likes: 1
Backfire during Idle
So i finished building my 86 vette when i came back from korea and after putting i wanna say 6-7k miles on it i know have a backfire that increases in noise during idle especially when driving. i replaced spark plugs and used a timing gun to make sure the timing was still right, but to no avail it is still backfiring. I miss my driving my vette so any advice would be much appreciated thanks.
p.s. ive been thinking maybe one of the sensors went out but im unsure on how i would test them
p.s. ive been thinking maybe one of the sensors went out but im unsure on how i would test them
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
Backfire intake or exhaust? I would check rocker arm adjustment and for worn cam lobe. If you are using flat tappet cam it's possible for lobe to wear flat. A leak down test would show if valves are sealing against valve seats.
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Do a leakdown test to see if you might have a bad exhaust valve or mechanical issue. Change plugs (again) and wires. If all ok, check injectors.
