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Fuel running down exhaust, to muffler

2533 Views 2 Replies 3 Participants Last post by  B10alia
2004 neon, sparkplug spit right out the top..... messed up treads, are the least of my worries..... went to start it and a fire broke out under the hood, then noticed fuel in #1 spark plug, and gas smell.... looked around and noticed gas pouring out my muffler..... HELP what could this be? and no we haven't started the car due to it pouring gas out the back, but prior to all this the cam sensor needed changed, and it idled very rough
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· Super Moderator
1966 Crown Coupe, 2016 200 S AWD, 1962 Lark Daytona V8.
17,289 Posts
Welcome to Allpar. You will want to tap or heli-coil the #1 plug hole to securely install the plug. It will be no good running on 3 cylinders.
A fuel injector would have to be stuck wide open for several minutes of key-on, not-running to fill an exhaust system up. I can't even see how that could happen unless the fuel pump relay was jumpered on with a failed injector.
I would not even attempt to crank or start the engine as the explosive/fire hazards of the fuel-loaded exhaust system could do a lot of damage and injury. Are you sure that it was gas pouring out? How did this happen?
You may want to remove the entire exhaust system and flush it out with lots of soapy water followed by a rinse and a thorough drying or just replace it.

· Registered
878 Posts
Wouldn't be surprised if the engine hydrolocked from the fuel in the cylinder, causing the soft threads in the aluminum head to let go. I would go after that problem first, as you might pull the helicoil loose if you do that first and then try to start the engine. Look for open injectors, as IC mentioned, or vacuum lines pulling fuel in. I don't know if the Neon has a vacuum-operated pressure regulator (I don't think it does, I've never heard of any Mopar that does), but I've seen a video of an old Ford EFI van that did this, and it turned out to be the regulator. I kind of doubt an injector. If you've ever seen one fire outside of an engine, you know it's more of a spritz than anything. The fuel pump is capable of moving a lot of fuel pretty quick, but the injector nozzle is so small that not much of it will come out. In the case of a returning-type injection system, in fact, most of the fuel ends up going right back to the tank.
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