[Sorrynotbryant]

Hey guys searched the threads and can definitely see the issue can be multiple things but couldn’t really spot if anyone had a similar experience.

first I had an issue with my fuel pump that included a CEL with the code for fuel pump flow and also had misfire upon heavy acceleration and loud backfire at random times. I Made the access hatch and noticed the 90 degree fitting was gushing. I got a new pump with upgraded drop ins and the ALM top hat and am no longer concerned about the pump. After the installation I drove around and heard the V still backfire. Once I’d park the idle would be pretty rough and would almost die on me. I thought this was an issue with the pump as maybe I just needed a retune. Well I got a call from the tuner and they are saying I’ve got a misfire on cylinder 4 and pulling timing.
They are going through with a diagnosis but just want to see if anyone has any ideas or if they’ve dealt with this and what the fix was. I have not heard any alarming sound within the engine bay but this is my first time dealing with an issue like this so I am pretty worried and am just trying to get the funds set aside for the worst lol.
I appreciate the help!

 

[SofaKingSlow]

Had it happen twice. Neither time was fuel related. May not be your solution, this is just what I experienced.

The first time was pushrods were too long. I had the block and heads trued/milled. Valves weren't closing completely. A set 0.0050 shorter than stock fixed it.

The other time was a spark plug whose ceramic insulation I cracked during installation. Took a couple weeks to manifest, but it did misfire.

 

[Sorrynotbryant]

Had it happen twice. Neither time was fuel related. May not be your solution, this is just what I experienced.

The first time was pushrods were too long. I had the block and heads trued/milled. Valves weren't closing completely. A set 0.0050 shorter than stock fixed it.

The other time was a spark plug whose ceramic insulation I cracked during installation. Took a couple weeks to manifest, but it did misfire.
View attachment 161041

Thank you for the response. Shouldn’t have an issue with the pushrods as I made sure to go with what was recommended by BTR for their cam on a stock block. So I’m truly hoping it’s just a plug. Was the issue resolved as soon as you swapped the plug?

 

[SofaKingSlow]

Was the issue resolved as soon as you swapped the plug?

Yes.
I ended up playing "musical chairs" with ignition components. Coil, plug, and wire to new, different homes. In my case, the misfire followed the plug. When I removed it from the new cylinder, the sliver of insulation fell out and it became obvious what the cause was.

 

[Sorrynotbryant]

Thanks all for the help. Shop called, compression showed healthy cylinders but plug wires were melted.

 

[PGA2B]

Accel Ceramics FTW!