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Hey,
New to this board. Just a quick question for all you pro's out there. I have a 2000 C5. Mostly stock, however, it does have a blackwing intake with corsa exhaust. I am getting a backfire on deceleration. (between 2000 and 3000 RPM) Also, I am getting a ping when I am on the highway at high RPM (holding close to redline). My thoughts are it is the air/fuel mixture but I have no idea how to fix the problem. Any thoughts.
Thanks
The Blackwing causes your engine to go leaner which causes ping. If you have a corvette tuner in your area you could have your car settings optimized(most tuners uses LS1-Edit).
Never have had anyone explain to me how a aftermarket air filter (i.e. Blackwing) fakes out the MAF into flowing more air than it can measure. IOW, I don't think the Blackwing is the problem with your pinging.
1. The knock sensor isn't working and therefore the PCM doesn't know to pull any timing out.
2. The combustion chambers have enough carbon buildup to cause detonation to occur. It could be minor, combining with #1, or it could be major, causing detonation to occur even with the max timing the PCM can pull out. In either case, check under the Tools menu for Tech Tips. There's a couple of procedures in there for de-carboning your engine.
3. Your PCV valve is flowing too much into your intake, actually pulling an oil mist into the intake air. Oil has a much lower octane rating than gasoline, and can cause detonation, as well as accelerated carbon buildup.
Hope this helps, have a good one, and enjoy your new ride!
Exhaust popping is normal on decel... more noticeable with aftermarket exhaust.
Pinging is another issue... you could have carbon build-up.
I and others have experienced pinging when driving the car easy for sometime and then getting on it hard... This goes away after some hard driving..
Try running your car hard for awhile and see if the pinging eases up.
Might be a very simple fix
mike
(heheh, sorry, couldnt help myself after seeing your subject line)
if you are getting an actual backfire (as opposed to just gurgling/popping on deceleration) then you most likely have an exhaust leak between the engine and rear axle.
btw, i've spent ALOT of time working on c5 exhausts recently. :cuss
Also check for oil consumption: source of carbon build up. Followed by pinging and pulled engine timing. Followed by richened mixture, incomplete combustion, additional carbon build up, and afterfiring (explosions through exhaust system, as opposed to backfiring through the intake system (a muffled thump under the hood)). A quick check for carbon: pull plugs and use a borescope to examine combustion chambers+pistons for carbon.
Does the afterfiring occur when the engine is cold, or also when hot? Cold afterfiring while the air pump is running is generally considered normal.
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Re: BACKFIRE!! (saltwaterfish.com)
You may have to have your air/fuel ratio set. Normally the car will relearn the settings after about 50 miles of driving. A good tuner should be able to do this for you.