Car Engine Running Rich

Reader Question

Hi my name is Aron I have a  Ford Windstar. The van is emitting fuel out
of the tail pipe.  I replaced spark plugs, plug wires, and ignition coil because it was miss firing. After replacing everything it is still missing and fuel is still coming out of the exhaust a computer test shows running to rich and miss firing. Don’t know what else to do. Please help? Thanks

Hello Aron,

Do you actually see fuel coming out the tailpipe? Raw fuel in liquid form, or just that the computer says the engine is rich and you smell the rich exhaust?

If you have a misfire, there are a few things that can cause it

1. Bad spark plugs and or plug wires – you can spray a small amount of water from a spray bottle on the plug wires to see if there is a bad spot in a wire, if there is it will spark when it hits the water.

2. Distributor cap and or ignition rotor under the cap

3. A vacuum leak somewhere in a rubber hose, a hose connection, a head gasket or intake gasket. Listen for a vacuum hissing noise under the hood, and look around for a vacuum leak in a rubber hose or gasket.

4. Internal engine troubles – bad piston, rings, cylinder etc. etc. – a compression test will tell you this

5. Head problems, blown head gasket, broken rocker arm or lifter problem etc.- a compression test will tell you this

6. Fuel injector problem, no fuel getting to a particular cylinder to burn or too much fuel to a particular cylinder- clogged or bad injector, bad fuel pressure regulator causing too much fuel to enter the engine. Fuel pressure test will tell you this

If you have too much fuel, you will usually find the crankcase full of fuel as well. Remove and smell the engine oil dipstick and smell for raw fuel. Raw fuel in the crankcase can be dangerous, and usually means there is a bad fuel pressure regulator, fuel pump or problem with the intake gasket.

Please share this with your friends,

Austin C. Davis

Posted in: Running Problems

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