P0300 lt1
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Teching In
Joined: Jun 2012
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P0300 lt1 I've been having this problem for some time now, code P0300 on my 1996 LT1. No other codes are being thrown. The spark plugs, O2 sensor, and MAF sensor are good. The car starts hard and backfires, especially under any load, when it hasn't been started for a day or so. I have a decent video of it if that'd help. It also occasionally puffs white smoke from the exhaust when it starts, although I'm not down on power so I doubt its a head gasket.
Any ideas what could be causing the misfiring? Fuel delivery, opti?
Any ideas what could be causing the misfiring? Fuel delivery, opti?
Check your fuel pressure. Might need a fuel filter or possibly a fuel pump. Once the fuel pressure is confirmed, you can move on from there. The opti is the go to for LT1s, but it is an 18 year old car at this point, so any number of things need to be checked as well.
You can try changing the pressure regulator at the rail, but I almost guarantee it's the pump.
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Teching In
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Super late update, pump fixed it. No codes, running well, only problem now is occasional puff of lingering white smoke on startup. The only thing I could think of is a head gasket issue, but there are no other signs of this as far as I can see. The engine feels strong, nothing looks milky
Teching In
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From: Gastonia nc.
I might be wrong but that sounds like a bad valve guid seal if it only does it when you first crank it up. If the seals are bad it will let oil down in your piston thus when you crank it up it burns the oil off and that would be you smoke you see. Hope that helped