LS3 backfire help
Thread Starter
Teching In
Joined: Jul 2012
Posts: 2
Likes: 0
LS3 backfire help I am new to this forum. I have a crate LS3 in a 55 Chevy. Speartech ECM. The engine has only had start up time and a few others, when I fire it up. Been in the project 2 years. Starts fine, but backfires through the exhaust. If I let it idle for a minute or so it gets better, If I give it a few quick blasts on the throttle (DBW), it gets better. Then, it will clean out on its own. I can shut it off and restart it and it seems fine. No check engine light on, but it is on when the ignition is on and cranking. I haven't run any codes yet- car is in the body shop and painted. Almost have it back together and will bring it home next week to finish.
Any ideas/suggestions would be greatly appreciated.
Thanks
Terry
Any ideas/suggestions would be greatly appreciated.
Thanks
Terry
Sometimes you have to run a while to get codes.. Have you actually driven the vehicle and/or let it get completely up to operating temps? Are you sure you are getting a true backfire? My 04 Cobra had stainless exhaust on it and on cold mornings(well, cold for Louisiana, 20 degrees or so), it would pop like crazy on the way down if I tach'd it up past 3000. My neighbors loved it when I rolled out early in the AM and held it in first to warm it up.
Thread Starter
Teching In
Joined: Jul 2012
Posts: 2
Likes: 0
I think it was the 2 year old gas. it wouldn't start the other day, so I put gas in it. seems to be ok now. It is still in the building process, and has only been off and on a trailer to the exhaust shop and body shop.
Cool. Definitely love a cheap fix! The Sta-Bil stuff(red liquid available at any parts store) really works. I've used it for far longer than the labeling indicates and still no problems. I'm religious with it in any of my gas cans and other power equipment and drop a little in the Jeep tank any time I don't expect to drive it for a while. Helps with moisture in the gas and ethanol-related funny business as well I believe.
