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Discussion Starter #1
Hi All,

P38 4.6 still with hesitating engine during acceleration.

MAF sensor readings are 23 at idle and 100 at 3000 rpm, so no MAF problem.
No sensor failure can be found with the Faultmate, everything seems OK.
Probably air leak in intake system, with idle running engine I haVE spray some highly inflamable brake cleaner around all the intake connections.
No changing in idle running so there is no leak.

During accelaration always missfire on nr 7, and P0172 and P0175
Have change the HT leads with Magnecor KV 85 leads, no difference.
Have change teh spark plugs also no difference.

Is it possible that during acceleration ,with fuel enrichment, it's harder to ignite the mixture ?
Should I also change the coil pack ?
Can it be possible that the coils are working bad if cold and do better if they get warm ?

Ally v8?

Regards,

Klaas
 

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Klass

Have you looked at the coils?
They sometimes degrade causing spark issues,

They are in blocks of 2 and can be bought seperately so maybe no need to change the whole coil pack.

Pull the HT leads off the coil pack and look at the condition.

Also check that the connection to injector 7 is secure.

Mine was loose on one of the injectors which caused an intermittent missfire.
 

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keithdixon said:
Klass

They are in blocks of 2 and can be bought seperately so maybe no need to change the whole coil pack.
The OP doesn't say if it is a GEMS or Bosch. The above is true for GEMS, Bosch have 2 coil packs.

Also a misfire on only no7 wouldn't explain a running rich code on both banks - are both O2 sensors switching correctly?
 

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1995-2002 Range Rover P38A
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No mention of compression test being carried out, if all the other bits like plugs, HT leads, injector and coils look ok then I would carry out a compression test, number 7 concerns me as the back end of the engine is a known cooling problem with old radiators.

You may have carboned up valves or one that is sligtly burnt, cause: bad fuel and junk engine oil
 
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