SOLVED - Cylinder 7 misfire

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

InterceptorF

Member
Joined
Mar 18, 2022
Posts
46
Reaction score
49
Location
COlorado Springs CO 80908
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.
 
OP
OP
InterceptorF

InterceptorF

Member
Joined
Mar 18, 2022
Posts
46
Reaction score
49
Location
COlorado Springs CO 80908
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

Full Access Member
Joined
Dec 29, 2016
Posts
2,437
Reaction score
3,122
Location
Indiana (formerly IL)
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__

Full Access Member
Joined
Apr 18, 2018
Posts
2,885
Reaction score
5,834
Location
Bucks county PA
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. 97A317EB-B81E-4C2A-8068-05C2CDD224DF.jpeg
 

Tonyv__

Full Access Member
Joined
Apr 18, 2018
Posts
2,885
Reaction score
5,834
Location
Bucks county PA
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
 

nonickatall

Full Access Member
Joined
Nov 19, 2022
Posts
692
Reaction score
1,257
Location
Germany
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 ..
 
Last edited:

Forum statistics

Threads
130,376
Posts
1,831,286
Members
93,959
Latest member
syrupdawg
Top