SOLVED - Cylinder 7 misfire

[InterceptorF]

New spark plugs, wires, lifters odd bank pushrods odd bank, injectors, oil pressure switch, egr seal on the intake… So I had a collapsed lifter in the odd bank and pulled the odd bank head. Replaced all eight lifters and pushrods. I had hoped the collapsed lifter was the cause of my misfire on cylinder 7 P307 but nope . The tick went away so good on that but I am still seeing a P307 after the engine idles for more than 5 minutes. I am looking at the injector as my next attempt.

 

[InterceptorF]

New spark plugs, wires, lifters odd bank pushrods odd bank, injectors, oil pressure switch, egr seal on the intake… So I had a collapsed lifter in the odd bank and pulled the odd bank head. Replaced all eight lifters and pushrods. I had hoped the collapsed lifter was the cause of my misfire on cylinder 7 P307 but nope . The tick went away so good on that but I am still seeing a P307 after the engine idles for more than 5 minutes. I am looking at the injector as my next attempt.

Also swapped coil 7 with coil 3

 

[rockola1971]

Swap spark plug wire and spark plug. Either could have a fault. Possible ignition coil wiring harness damage to #7 Ignition coil.
Quick and dirty check on spark plug wires is fire engine up at night and pop the hood. KEEP HANDS IN POCKETS! Look for lightning flashes coming of spark plug wires to engine ground and any other metal surfaces near the plug wires. Listen for the distinct snapping noise the spark makes when its jumping an air gap.

 

[Tonyv__]

New spark plugs, wires, lifters odd bank pushrods odd bank, injectors, oil pressure switch, egr seal on the intake… So I had a collapsed lifter in the odd bank and pulled the odd bank head. Replaced all eight lifters and pushrods. I had hoped the collapsed lifter was the cause of my misfire on cylinder 7 P307 but nope . The tick went away so good on that but I am still seeing a P307 after the engine idles for more than 5 minutes. I am looking at the injector as my next attempt.

Did you make sure the lifter didn’t wipe out the cam? My bad lifter did this to my cylinder 7 lobe.

 

[MassHoe04]

Did you make sure the lifter didn’t wipe out the cam? My bad lifter did this to my cylinder 7 lobe. View attachment 386207

Wow! Looks more like a pulley than a cam lobe...

 

[Tonyv__]

Wow! Looks more like a pulley than a cam lobe...

Yeah I had a misfire at idle for like 6 months I was chasing. I finally caved one day after trying everything I was capable of trying to diagnose and pulled the heads. Found a bad lifter than the cam. The misfire also ended up killing my catalytic converter shortly after. It’s all straightened out now though

 

[wjburken]

Did you make sure the lifter didn’t wipe out the cam? My bad lifter did this to my cylinder 7 lobe. View attachment 386207

Definitely chewed through the hard candy shell and into the soft nougatty center on that one.

 

[wjburken]

Did you make sure the lifter didn’t wipe out the cam? My bad lifter did this to my cylinder 7 lobe. View attachment 386207

Definitely chewed through the hard Candy shell and into the soft nougatty center on that one.

 

[nonickatall]

I would first make a test of the engine compression.

That tells you if the system of pistons, valves, camshaft and so on, do what it should do.
That is the Fundament.

When after that, the ignition and Injektion is correct, the engine will run proper ..

 

[InterceptorF]

Did you make sure the lifter didn’t wipe out the cam? My bad lifter did this to my cylinder 7 lobe. View attachment 386207

Holy Crap! Yes, I did check my cam through the lifter bore - it was fine but I did replace the injector and the engine smoothed right out.

 

[InterceptorF]

I think the issue was the lower o-ring on the #7 injector, it looked wonky, but I had a replacement injector so just replaced it. The engine smoothed right out. No test drive yet as I also replaced the oil pump and o-ring so the oil pan RTV is curing. It's so much easier to drop the oil pan with the 6" lift; still not 'easy' but does help! Hoping all this work on it the past couple of months is coming to an end.

 

[InterceptorF]

RESOlVED: It was definitely the #7 injector! Runs smooth and no codes are being thrown! Also the oil pressure is back to a solid normal >> 38-- 46 psi.

 

[Tonyv__]

Holy Crap! Yes, I did check my cam through the lifter bore - it was fine but I did replace the injector and the engine smoothed right out.

Good. Would suck to have to rip it all apart again.

 

[Rocket Man]

RESOlVED: It was definitely the #7 injector! Runs smooth and no codes are being thrown! Also the oil pressure is back to a solid normal >> 38-- 46 psi.

Awesome. Thanks for coming back and updating the thread.

 

[89Suburban]

RESOlVED: It was definitely the #7 injector! Runs smooth and no codes are being thrown! Also the oil pressure is back to a solid normal >> 38-- 46 psi.

Yay!!!!

 

[RAMurphy]

Always a great day when you resolve an issue. Nice Job.

 

[Joe-ty]

Also swapped coil 7 with coil 3

Why would you swap with the number three? Why don’t you swap with number five? Is there a difference?