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Discussion Starter · #1 ·
I posted a few weeks ago as I was digging into this but wanted a clean thread now that issues are reduced and narrowed down - thanks for the help with those.

Getting Miss Fire codes for cyl 2, 5 and 7. I swapped coils around and replaced all of the coil packs on the passenger side - still have the issue... same cylinders.

I replaced all the spark plugs ... still have the issue... same cylinders.

My next move is to either move around the fuel injectors, but that is a crap ton of work to do a few times.... or replace the fuel filter under the rear seat thinking it might be a fuel delivery issue upstream from the injectors. Is this the right next step?

I am guessing that with new plugs and coils (and I can test the coils using This thing and all the readings look the same for each cyl, so assuming coils are good??

Im just not confident in next steps.

Guidance is greatly appreciated.
 

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2006-2009 Range Rover MkIII / L322
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What are the exact DTC codes, are the P0302, 0305, and 0307 or something else? Flashing check engine light, or reduced performance message on the dash?
 

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Discussion Starter · #3 ·
p0300
p0302
p0303
p0304
p0307
p0316
(cyl 4 is new as of this morning)
CEL is not flashing and the reduced performance message is not present... but I have not driven it on the road.
you can absolutely feel the shake from the misfires.
 

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There's nothing in common with those misfires electrically, the cylinders are grouped electrically as cylinders 1,4,6 and 7, and 2,3,5, and 8 from the ECM. Those cylinders are fired individually from the ECM but monitored as two groups (those noted above). The ECM uses the crankshaft sensor to figure out which cylinder is not firing, and produces codes P0351 thru P0358 for a non firing coil. So since you don't have any of those codes present, it looks like your coils should be working. You essentially have issues with the 4 center cylinders in the engine, 2 on each side. You could try swapping a coil from any cylinder but 2,3,4 or 7 into one of those cylinders and see if the codes change but you already replaced coils on 2,4,6,and 8, don't know what happened with 3 and 5 odd number cylinders are on the right bank, evens on the left bank.

Any work done on the engine prior to this issue, how many miles, did you clean up the rubber boots on any coil that you didn't replace?

When you replaced the plugs did the center 4 look any different than the outer ones?

Any oil leaks down near the crankshaft sensor? You may have a bad sensor, or dirty connection.
 

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2007 Range Rover 4.2 SC V8
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What tool are you using for codes? I know you're not getting the code but a failed o2 sensor can cause misfires.
 

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Discussion Starter · #8 ·
There's nothing in common with those misfires electrically, the cylinders are grouped electrically as cylinders 1,4,6 and 7, and 2,3,5, and 8 from the ECM. Those cylinders are fired individually from the ECM but monitored as two groups (those noted above). The ECM uses the crankshaft sensor to figure out which cylinder is not firing, and produces codes P0351 thru P0358 for a non firing coil. So since you don't have any of those codes present, it looks like your coils should be working. You essentially have issues with the 4 center cylinders in the engine, 2 on each side. You could try swapping a coil from any cylinder but 2,3,4 or 7 into one of those cylinders and see if the codes change but you already replaced coils on 2,4,6,and 8, don't know what happened with 3 and 5 odd number cylinders are on the right bank, evens on the left bank.

Any work done on the engine prior to this issue, how many miles, did you clean up the rubber boots on any coil that you didn't replace?

When you replaced the plugs did the center 4 look any different than the outer ones?

Any oil leaks down near the crankshaft sensor? You may have a bad sensor, or dirty connection.
No oil leaks.
Only recent "engine" work was a water pump and alt.
Plugs all looked the same - pretty decent actually brown/grey in color.. not white, not wet.
Didnt do anything with the boots.. easy enough to try just in case.
I wish there was a way to monitor fuel pressure on these things... I am wondering if woth 235k miles and unknown fuel pump/filter status... maybe this is a low pressure scenario reducing quality of "fire" from the cyls (why there are more than one reporting)

Thinking I might do a compression check to be sure the engine mechanicals are good.... then replace the filter... then rebuild injectors?
 
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