P0301 cylinder 1 misfire
Thread Starter
2nd Gear Member
Joined: Nov 2007
Posts: 156
From: Alaska
P0301 cylinder 1 misfire
I really think I got some bad gas. I drove 1700 miles from dc to san antonio and stopped at a Flying J for a fill up. I was on the on ramp and the CEL comes on, My Diablo came with the code above along with a system to rich code. I added octane boost and that code went away. I got to san antonio and replaced all the plugs and the dang code will not go away. I am also thinking a coil pack and injectors. I will switch a coil pack with another to see if I get a misfire on another cylinder. If that doesnt work, Injectors? Im running a Kb sc setup and that makes for a time consuming job. any ideas are helpful. I can feel the misfire especially if I accelerate with a load (higher gear for low speed) Thanks
Matt
Matt
3rd Gear Member
Joined: Nov 2006
Posts: 960
From: Kansas City
RE: P0301 cylinder 1 misfire
If you have a code coming up for a misfire on a specific cylinder, bad gas is not the problem. It would be limited to spark plug, injector, coil, or bent valve resulting in no compression. You didnt say if you cleared the code or not. If you dont clear it, it will take quite awhile for the light to go off by itself. If you have a misfire still there after replacing the plugs, you will feel it during normal driving. If the problem is still there, unplug the injector to that cylinder while the engine is running. Listen and see if the idle changes. If idle changes, then the injector is good. Next, swap a coil and see if the misfire goes to the swapped cylinder. That will tell you if the coil is bad.
4th Gear Member
Joined: Nov 2007
Posts: 1,699
From:
RE: P0301 cylinder 1 misfire
ORIGINAL: SCCAGT
If you have a code coming up for a misfire on a specific cylinder, bad gas is not the problem. It would be limited to spark plug, injector, coil, or bent valve resulting in no compression. You didnt say if you cleared the code or not. If you dont clear it, it will take quite awhile for the light to go off by itself. If you have a misfire still there after replacing the plugs, you will feel it during normal driving. If the problem is still there, unplug the injector to that cylinder while the engine is running. Listen and see if the idle changes. If idle changes, then the injector is good. Next, swap a coil and see if the misfire goes to the swapped cylinder. That will tell you if the coil is bad.
If you have a code coming up for a misfire on a specific cylinder, bad gas is not the problem. It would be limited to spark plug, injector, coil, or bent valve resulting in no compression. You didnt say if you cleared the code or not. If you dont clear it, it will take quite awhile for the light to go off by itself. If you have a misfire still there after replacing the plugs, you will feel it during normal driving. If the problem is still there, unplug the injector to that cylinder while the engine is running. Listen and see if the idle changes. If idle changes, then the injector is good. Next, swap a coil and see if the misfire goes to the swapped cylinder. That will tell you if the coil is bad.
Gentleman's Relish
Joined: Feb 2005
Posts: 13,189
From: AZ
RE: P0301 cylinder 1 misfire
ORIGINAL: mattsimonton
I really think I got some bad gas. I drove 1700 miles from dc to san antonio and stopped at a Flying J for a fill up. I was on the on ramp and the CEL comes on, My Diablo came with the code above along with a system to rich code. I added octane boost and that code went away. I got to san antonio and replaced all the plugs and the dang code will not go away. I am also thinking a coil pack and injectors. I will switch a coil pack with another to see if I get a misfire on another cylinder. If that doesnt work, Injectors? Im running a Kb sc setup and that makes for a time consuming job. any ideas are helpful. I can feel the misfire especially if I accelerate with a load (higher gear for low speed) Thanks
Matt
I really think I got some bad gas. I drove 1700 miles from dc to san antonio and stopped at a Flying J for a fill up. I was on the on ramp and the CEL comes on, My Diablo came with the code above along with a system to rich code. I added octane boost and that code went away. I got to san antonio and replaced all the plugs and the dang code will not go away. I am also thinking a coil pack and injectors. I will switch a coil pack with another to see if I get a misfire on another cylinder. If that doesnt work, Injectors? Im running a Kb sc setup and that makes for a time consuming job. any ideas are helpful. I can feel the misfire especially if I accelerate with a load (higher gear for low speed) Thanks
Matt
6th Gear Member
Joined: Sep 2006
Posts: 11,278
From: Gainesville, FL
RE: P0301 cylinder 1 misfire
ORIGINAL: Derf00
I'm going to go with a bad coil or bad plug. Go ahead and diagnose it the correct way though to remove all variables. If it was an injector it would give you a system too rich code (unless the injector was stuck on which is highly unlikely)
I'm going to go with a bad coil or bad plug. Go ahead and diagnose it the correct way though to remove all variables. If it was an injector it would give you a system too rich code (unless the injector was stuck on which is highly unlikely)
Thread Starter
2nd Gear Member
Joined: Nov 2007
Posts: 156
From: Alaska
RE: P0301 cylinder 1 misfire
Turns out it was a bad piston. There was a quarter inch scar like raise on my #1 piston. Im hoping it was the only one and nothing else was damaged. I took it to Murillo motorsports down in san antonio texas. They put a borriscope down in there and let me have a look aswell. So what are the odds its just that piston? The crappy thing is that the motor in the car only has 10 k on it and is a race motor built by Johnny lighting performance. Im not having a good day. I apologize if this doesnt make any sence, im nautious and very tired.
Thread Starter
2nd Gear Member
Joined: Nov 2007
Posts: 156
From: Alaska
RE: P0301 cylinder 1 misfire
they said the ring lance was lifting. I looked into the borriscope and saw a 1/4 inch raise on my number 1 piston. Hopefully it was just that piston and they will replace it and be done with it, but if not...Im looking at a whole new rebuild. That motor has only 10 k on it. Is there some kind of fault with KB? This will be the 3rd motor put into it if they cant do a rebuild or a quick fix. They are going to put it on a dyno and tune it after they work their magic. I took it to Murillo motorsports in san antonio texas. They work mostly with boosted stangs.