NEED HELP Code po300 engine misfire detected
Thread Starter
Racer
Joined: Jul 2000
Posts: 440
Likes: 0
From: Naples, Florida
NEED HELP Code po300 engine misfire detected
It is like the engine is runing on 4 or 5 cly. pull all spark plugs .3 were 4 was wet with gas, like not fireing , maybe coils? valve sping? please help
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Mike
It could be a number of things.
Start easy. Check the spark plug wires. If there stock, they should measure 250-750 ohms. Normally there in the 350 ohm range. Make sure the wire and boots are not cut, burnt or damaged and make sure the metal connections in the boots are NOT corroded or deteriorated. The connection inside the coil end of the boot should SNAP into the coil with a nice click. Make sure that the spark plug wires are arcing.
The engine wiring harness has been known to chafe at back of the manifold. Theres a bracket back there that the harness bends around and that can cut the wires and cause one or more coils to fail.
In this picture you can see the harness on the drivers side of the engine and the bracket at the back of the engine that it bends around. Look at that point for abrasion.
If you look to the right you can also see TWO side by side black white stripe wires by the valve cover. They connect on the back of the drivers head. Those are the ground wires for the coils and fuel injectors.
Hope this helps
BC
It could be a number of things.
Start easy. Check the spark plug wires. If there stock, they should measure 250-750 ohms. Normally there in the 350 ohm range. Make sure the wire and boots are not cut, burnt or damaged and make sure the metal connections in the boots are NOT corroded or deteriorated. The connection inside the coil end of the boot should SNAP into the coil with a nice click. Make sure that the spark plug wires are arcing.
The engine wiring harness has been known to chafe at back of the manifold. Theres a bracket back there that the harness bends around and that can cut the wires and cause one or more coils to fail.
In this picture you can see the harness on the drivers side of the engine and the bracket at the back of the engine that it bends around. Look at that point for abrasion.
If you look to the right you can also see TWO side by side black white stripe wires by the valve cover. They connect on the back of the drivers head. Those are the ground wires for the coils and fuel injectors.
Hope this helps
BC
