Hey guys! Just swapped to a newer 4.0 engine with 80k in my 02 disco 2. Old engine slipped a sleeve and was misfiring on and off on cylinder 8. It had 185k miles so decided not to rebuild the old 4.0.


I went through the new motor, pinned the sleeves, new seals throughout, rings, spark plug coils, and fuel injectors. Went to start it, it ran well until misfire on cylinder 8 again. Seemed to have carried over from the old engine. Has me thinking electrical? Maybe the spark plug wires are going bad?


many ideas?

 

I would swap the plug wires with another cylinder to rule out the wire. Maybe also verify you're getting spark on #8 with a tester while you're in there.

 

Hey @andino

I went through checked spark, changed cylinder 8 plug wires and plugs, nothing different. replaced the spark plug pack and while in there rebuilt the fuel injectors. Now no specific code for cylinder 8 just random misfire code.

Except now a new symptom. I just got codes for mass airflow sensor, Camshaft position sensor, oxygen sensors (1st and 2nd both sides), all of which is showing electrical fault.

Checked all the fuses and nothing. got concerned about a pinched or broken wire. So opened up the harnesses and nothing pinched or severed.

Need some new ideas...