Misfire
#1
Senior Member
Thread Starter
Misfire
I have a cylinder 4 misfire detected throwing code P0304.. Truck runs rough then if I put gas in it it does fine.. Any ideas? Plugs and wires? Coil pack?
#2
Is this on the new truck? When's the last time plugs were done? How many miles are on it?
I would make sure the coils are all connected and everything is bolted down good. You can always try swapping plug/ coil to another cylinder to see if the misfire moves. If it does you've found your problem. Might be in your best interest to replace all plugs and coils if they haven't been done in a while...
I would make sure the coils are all connected and everything is bolted down good. You can always try swapping plug/ coil to another cylinder to see if the misfire moves. If it does you've found your problem. Might be in your best interest to replace all plugs and coils if they haven't been done in a while...
#4
Senior Member
Thread Starter
Yeah it's on the new truck.. Guy I bought it from said he replaced 2 coils on it.. I have no idea why he didn't replace them all at once..
#5
Senior Member
Thread Starter
Just went to the gas station and my oil pressure gauge dropped and the light came on.. When I got back in the truck and turned it on it was back to normal?
#6
Senior Member
Check your fuel tank vent valve for obstructions and dirt. When they get clogged or dirty they can (for some damn reason) cause an engine misfire.
#7
Senior Member
iTrader: (1)
I wonder if this is why mine is idling rough
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#8
Senior Member
Is this on the new truck? When's the last time plugs were done? How many miles are on it?
I would make sure the coils are all connected and everything is bolted down good. You can always try swapping plug/ coil to another cylinder to see if the misfire moves. If it does you've found your problem. Might be in your best interest to replace all plugs and coils if they haven't been done in a while...
I would make sure the coils are all connected and everything is bolted down good. You can always try swapping plug/ coil to another cylinder to see if the misfire moves. If it does you've found your problem. Might be in your best interest to replace all plugs and coils if they haven't been done in a while...
Anyway, try swapping the coils/injectors and see what that gets you.
#10
Ford Owner
If it is just the number 4 cylinder, check the spark plug socket for coolant. Those heater hoses over the number 4 cylinder can leak causing a misfire. I would suggest taking out the plug, cleaning out the plug socket with a round wire brush, WD40 and rags, clean the COP connection, and put it back together. Use di-electric grease on the plug/cop connections.
While cleaning look for signs of engine coolant or oil. If you find any, you most likely have a coolant leak of a oil leak at your valve covers. After doing all of that, it will most likely run fine for a little while and then start missing again as that water starts to leak and get down into the plug socket. The leaks usually start around the quick disconnect fittings of the heater hoses next to the firewall. since they are usually small leaks, you will hardly notice them because they evaporate when the coolant hits the hot engine. they can however cause a really bad miss.
While cleaning look for signs of engine coolant or oil. If you find any, you most likely have a coolant leak of a oil leak at your valve covers. After doing all of that, it will most likely run fine for a little while and then start missing again as that water starts to leak and get down into the plug socket. The leaks usually start around the quick disconnect fittings of the heater hoses next to the firewall. since they are usually small leaks, you will hardly notice them because they evaporate when the coolant hits the hot engine. they can however cause a really bad miss.