P0300 misfire
Thread Starter
Intermediate
Joined: Feb 2023
Posts: 43
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P0300 misfire
Hello, my car was on jackstands for 3 months while I did a clutch job and torque tube rebuild. Took a while because I had to wait for parts and find time to work on it.
I didn’t think about putting fuel stabilizer in it because I figured it wouldn’t take but a week or 2 to do. Boy was I wrong!!!! I put some fuel stabilizer and octane booster in it once it came off jackstands. It’s making a clicking/slight knocking sound at idle. It speed up as rpm’s go up and goes away at 3,000 rpm.
I put fresh gas in it but it’s still has a check engine light that’s blinks on the highway and goes solid at traffic light.
I figure some new spark plugs and a fuel system cleaning and new fuel filter will fix the issue but what do y’all think????
Thank you for the responses, much appreciated.
I didn’t think about putting fuel stabilizer in it because I figured it wouldn’t take but a week or 2 to do. Boy was I wrong!!!! I put some fuel stabilizer and octane booster in it once it came off jackstands. It’s making a clicking/slight knocking sound at idle. It speed up as rpm’s go up and goes away at 3,000 rpm.
I put fresh gas in it but it’s still has a check engine light that’s blinks on the highway and goes solid at traffic light.
I figure some new spark plugs and a fuel system cleaning and new fuel filter will fix the issue but what do y’all think????
Thank you for the responses, much appreciated.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,496
Likes: 3,999
From: Cape Coral, Florida
Well you can try that but if that doesn’t fix it you should take the car to a diagnostic shop and let them quickly diagnose it…without some specialized equipment which they use you’ll only be guessing at that can get expensive…in the meantime you can try listening to each injector with a long screwdriver and see if each one “clicks” while the engine is running…if not just lightly tap on it and if it’s mechanically stuck closed that just might free it up…a blinking MIL is a “cat damaging” misfire so you don’t want to drive it to much until it gets repaired or you’ll be replacing your catalytic converters.
Racer
Joined: Oct 2003
Posts: 274
Likes: 42
From: Venice, Florida
Put a can of Seafoam in the fuel tank and take it for a 15 minute drive (swerve left and right at low safe speed to mix it in w/gas) after following the directions on the can. Check all plug wires are seated properly on both sides and aren't cracked. Pull plugs and check for one that's black sooted or wet. Do a fuel pressure leakdown test to look for a leaky injector. Like C5 said tap with the handle end of the srewdriver (while it's running so the injectors have power going to them).
Question: How much old gas was in the car vs. how much did you add?
Question: How much old gas was in the car vs. how much did you add?
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,496
Likes: 3,999
From: Cape Coral, Florida
If you added octane booster and stabilizer to a full tank it only goes into the left tank …after the right tank is empty the fuel in that left tank will then be used.
