why does cylinder 7 keep misfiring even after I replaced the coil, sparkplug, and wires on my 02 Jag S-Type 4.0L?
Asked by gcicca Sep 16, 2014 at 04:13 PM about the 2002 Jaguar S-TYPE 4.0L V8 RWD
Question type: Maintenance & Repair
after my mechanic replaced the ignition coil and sparkplug on cylinder 7 and fixed any wiring as well, #7 cylinder will misfire and engine light comes on after a driving for a little while. This has happened 5 times
5 Answers
Do a compression test. See if #7 is lower than the others
That,s the only way,to know,,
i was told that you must replace all coil packs when you replace one or the one you replace will keep going out! Have anyone else heard this?
Have the fuel injector wires looked at. I had this happen to me before, but it was cylinders 1 and 3. I looked at the the wiring, even all the wire that was factory wrapped and found wires to be broken in half.
Auto_Centric answered 5 years ago
2019 Anyone viewing this should be told with a proper IDS-VCM scan tool this could have be isolated in 15min. Expand your skill set! $ y = a(1 - r)x