CEL p0300 misfire

jeeeep

Hooked
I'm afraid they will get foul out with all the shit I put in the fuel. Any tips before I put in the new plugs?
check the gap to make sure they are gapped properly, I don't trust them to be gapped out of the box and put some high octane fuel in the tank.

When I had water in my tank I think I put about 4 bottles of seafoam to help dry it out; it ran rough for a bit because there wasn't much gas in there but once I put the 5 gal of high octane fuel I had on hand, I shook Jeep side to side to mix it and then ran it, it was fine.

I ran it around the block a few times and it's been fine since.

Check the plug again, I'd check the one that was the worst as it will likely be the one to foul.

how are the plug wires?
 

OverlanderJK

Resident Smartass
check the gap to make sure they are gapped properly, I don't trust them to be gapped out of the box and put some high octane fuel in the tank.

When I had water in my tank I think I put about 4 bottles of seafoam to help dry it out; it ran rough for a bit because there wasn't much gas in there but once I put the 5 gal of high octane fuel I had on hand, I shook Jeep side to side to mix it and then ran it, it was fine.

I ran it around the block a few times and it's been fine since.

Check the plug again, I'd check the one that was the worst as it will likely be the one to foul.

how are the plug wires?
All might plugs were wrong too when I just installed them.

Also can’t you leave one of the fuel lines disconnect and turn the key on to activate the pump and flush it out? Put some good gas in the tank and run it out.
 

Seahawkfan

Hooked
All might plugs were wrong too when I just installed them.

Also can’t you leave one of the fuel lines disconnect and turn the key on to activate the pump and flush it out? Put some good gas in the tank and run it out.
That is what I wanted to do but it's not as simple as it used to be.
 

jeeeep

Hooked
All might plugs were wrong too when I just installed them.

Also can’t you leave one of the fuel lines disconnect and turn the key on to activate the pump and flush it out? Put some good gas in the tank and run it out.
On my 2010 JKU the pump would shut off after about 10 seconds with the key on; I think it's a safety feature but would've been great if there was a way to keep the pump running for this type of thing.

My neighbor helped me for the 1st 30 minutes but quickly realized it would take a long time as this rate (y)

I rigged up a hose to the end of the fuel line that I could put into a gas can so I could keep cycling the key. Took a couple of hours to get three 5-gal cans filled. I ran out the last 5 or so gallons with the seafoam and premium gas.
 

OverlanderJK

Resident Smartass
On my 2010 JKU the pump would shut off after about 10 seconds with the key on; I think it's a safety feature but would've been great if there was a way to keep the pump running for this type of thing.

My neighbor helped me for the 1st 30 minutes but quickly realized it would take a long time as this rate (y)

I rigged up a hose to the end of the fuel line that I could put into a gas can so I could keep cycling the key. Took a couple of hours to get three 5-gal cans filled. I ran out the last 5 or so gallons with the seafoam and premium gas.
Shut off with the hose disconnected or shut off with everything connected.
 
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