Engine missfiring

Maybe it needs new plugs, or the coil pack? But maybe it's something else. Only way to find out is to put the Peugeot diagnostics onto it, or keep changing bits till you get lucky.

Thank you for the quick reply Ian.the guy has said he has tried new spark plugs but if it was coil packs wouldn't it throw a fault code or engine light on at least

I'm not sure how the built-in test system could monitor the output of the coil pack, so I'll say probably not. It could certainly see a problem on the input side, but I doubt the opposite. This sounds like a marginal problem, so you may well be able to see a spark with a test plug regardless.

I know I'm arguing against my first reply now.....

Coil pack does not always throw a fault if misbehaving.

Check plugs are the correct ones for the engine and make sure the gap is set correctly.

If the plugs are correct/gapped properly, see if you can borrow a coil pack from someone and try it to see if it cures the problem.

You may have a leaky or sticky injector also, you could try running a decent flush in the fuel to see if you get an improvement. Or take it for an Italian tune up.....

Thank you both for the replies.I have found a post on a forum about the hydraulic tappets need changing for a similar problem is this a common problem on these engines? Is it a hard job to do ?

I find it hard to believe that hydraulic tappets which needed replacement would get better when the engine was hot - before you start dismantling (which requires the camshaft to be removed, so yes, quite a job) put a can of something like this into the oil.

but the post said to try and and change the oil grade to a thinner grade but I suppose it would be worth trying as you have said some oil treatment first and various other things coil pack,plugs its a shame as he has it up for sale cheap and in a nice condition. i don't want a massive headache on my hands

Walk away and find a better one is my advice.

So picked up the 307cc on Saturday cheaper than I planned but got it home.been doing 50 Mile round trip in it nearly every day and I got to say I am growing more fond of it.but the misfire is strange it's only there when it's cold mostly checked for fault codes and there was one p0141 so decided to clear it and see what happens done nearly 150 miles and it hasn't returned is it worth changing the O2 sensor or leave it.when it's ticking over there is a slight shake to the car but nothing major not sure if anybody else has come across this before.any advice appreciated

Since it's only when cold, I still fancy that its a marginal ignition problem. Worth trying another coil pack?

IanML said:

Since it's only when cold, I still fancy that its a marginal ignition problem. Worth trying another coil pack?

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Thank you for your reply IanML.i think it could be my starting point.but came down the dual carriage way tonight and up to about 70 ish (wasn't going no faster honestly ?) and it feels like it's holding back when accelerating and now it's also starting to hold back when pulling off at junctions stuttering and spluttering.tried the code reader and still nothing.but checked on the freeze frame data on the reader and it came up with code PO141

P0141 OBD-II Trouble Code: O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2).

I suppose it is possible that fuel injection is being messed up by incorrect O2 sensor reading. It would be a good idea to confirm with Peugeot Planet 2000.

IanML said:

P0141 OBD-II Trouble Code: O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2).

I suppose it is possible that fuel injection is being messed up by incorrect O2 sensor reading. It would be a good idea to confirm with Peugeot Planet 2000.

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What is Peugeot planet IanML ? Do you think also a blowing exhaust could contribute to it

Peugeot Planet is the specific diagnostic kit for Peugeots and can read and trace all information, whereas a generic reader will only give you limited (and sometimes wrong) information.

A blowing exhaust will not help a possible 02 sensor fault

What is Peugeot Planet

If you want to get your own, do EBay search for "Lexia 3".

Just tried to pm the nearest person to me with Peugeot planet but I am unable to send it because I have not had enough posts ??.I hope it's something trivial and it's a simple fix.got in this morning and it wouldn't rev unless I put my foot flat down.got a bit of back fire to and then it cut out.im hoping it's going to be something simple and it doesn't cost to much money as it seems a shame to scrap it or sell it as spares and repairs

So a update !!! Took the car to kwik fit for the blowing exhaust I collected it and they told me exhaust was fine they put it on the diagnostics and found P0141.so I changed the rear O2 sensor and it made no difference.so I had a look around myself checked plugs they where fine,checked the coil pack it looks fairly new and still isn't any diferant.but it's not backfiring through the exhaust it's backfiring through intake box.i have learned now then when I get in it in the mornings I have to leave it tick over for a few minutes till it gets warm otherwise it doesn't rev or respond.other than that it drives ok I'm getting good mpg out of it on my usual journey.and it pulls well when it's warm it's confusing

New coil packs do fail.