Peugeot Expert 1.9 - 'Flat' Spot

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Wed 9 Feb 2011 18:57
Peugeot Expert 1.9 - 'Flat' Spot - daview

During driving, whether it be around town or motorway a 'flat' spot occurs with a cloud of white smoke.......have tried an injector cleaner additive in the fuel but does not seem to have improved the situation......any ideas anyone?

Cheers

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Wed 9 Feb 2011 21:50
Peugeot Expert 1.9 - 'Flat' Spot - Railroad.

Daview if you ever find what your problem is please let me know 'cos a mate of mine has one of these with exactly the same problem. The only thing is it's only occurred since he replaced the clutch.....

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Wed 9 Feb 2011 22:52
Peugeot Expert 1.9 - 'Flat' Spot - Peter.N.

White smoke is usually a sign of unburnt fuel but on a diesel its almost impossible for it to misfire at speed unless the pump timing suddenly changes. I think you will find that one injector has a wire connected to it, this is used to control the injection point, or rather the electrics in the injector are, check the connection, otherwise the injector could be faulty - but its a long shot..

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Thu 10 Feb 2011 01:13
Peugeot Expert 1.9 - 'Flat' Spot - unthrottled

I thought the same. But if a cylinder is misfiring, the driver would surely notice that the engine felt rough, no? There's no mistaking a 4 pot running on 3!

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Thu 10 Feb 2011 09:08
Peugeot Expert 1.9 - 'Flat' Spot - daview

I was going down the same road about injectors hence the cleaner.....drives perfectly fine in general but it occurrs now and again when throttled off and back on

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Thu 10 Feb 2011 18:37
Peugeot Expert 1.9 - 'Flat' Spot - unthrottled

Could it be our old friend the EGR valve not opening and closing progressively? If you've been driving at high load, then ease off, and the EGR opens too quickly and dumps a load of exhaust gas with almost no oxygen in, that would explain almost complete misfire, but without any roughness...

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Fri 11 Feb 2011 09:07
Peugeot Expert 1.9 - 'Flat' Spot - daview

Hadnt thought of that one......is there away of diagnosing this without replacing?

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