intermittant fault eng code p8c

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mickeybo
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intermittant fault eng code p8c

Post by mickeybo » 01 Jul 2010, 10:22

406 2.1 1997 This car drives 100% but just recently has developed a intermittant fault. Some times when your driving car just cuts out for no apparent reason
starts to chug a bit before cutting out. will re- start again with key no problem. Took car to main peugeot dealers to-day for a code read came up
intermittant fault needle lift sensor consistency function(/) anomay (ies) a/b/c can anyone shed some light on this please
Best Regards Mickeybo

KP
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intermittant fault eng code p8c

Post by KP » 01 Jul 2010, 11:40

Sounds like the injector with the sensor is causing issues. check its cabling isn't chaffed on anythnig and that the connector is ok. failing that you'd be best trying another known good one.

jgra1
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intermittant fault eng code p8c

Post by jgra1 » 01 Jul 2010, 12:10

also, Mickey, if the 2.1 is anything like the 1.9.... there is only one injector with a sensor.. but it senses for all 4... the sensor detects lift and drop of the injector, which no longer occurs if there is a drop in fuel pressure for example..

mine LS shows a fault when my fuel delivery pressure to all 4 injectors drops (blocked filter)

John

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CitroJim
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intermittant fault eng code p8c

Post by CitroJim » 01 Jul 2010, 12:39

I reckon the light may be shining on a bit of a red herring here..

In my experience, the needle lift sensor makes little obvious difference to the running of the engine when it fails. It can be tested easily enough with an ohmmeter and should read around 100 ohms.

I would suspect the NLS fault is a secondary mansifestation of the true problem. I cannot see an intermittent NLS being the cause of stumbles as you describle.

Lucas EPIC pumps are fantastic devices by and large but they do have an Achille's heel and that is air ingress. I'm thinking that air ingress is the root cause of the problem. Favourite on the EPIC is split/perished leakoff pipes followed by a leak at the filter housing or primer bulb.

Air getting in will reduce pressure in the pump intermittently with will in turn cause a much reduced injection of fuel leading to stumpbling and insufficient volume/pressure to operate the Needle Lift Sensor properly.

Air leaks need to be dealt with as in extreme cases they can cause an engine runaway.

Watch the translucernt fuel supply pipe carefully between the filter and pump and watch for any air bubbles. If yoiu see them, fix them and the problem may well go away.

I'm thinking the Pug garage you took for the code reading were short on knowledge. There is a whole raft of tests the dignostic machine can perform on the EPIC pump in addition to the basic reading of codes. It is essential that all the tests are run to be able to correctly interpret what the coses are telling you and to arrive at a good diagnosis...

Cutting a bit of slack here, it is skilled work and not really in the domain of the average garage fitter type of person.

If you are unable to progress this problem, go to a diesel specialist rather than a general garage.