Intermittent missfire

[wilsofar]

Until I had the High Pressure Fuel Pump replaced I was faced with every possible type of hesitation/misfire etc,non of which had been identified by the main dealers ,the fault codes (as always) sending them on a wild goose chase.

Timing chain,coil packs,plugs,battery,thermostat,we're all replaced as being the culprits but did not fully solve the problems,until the HPFP was replaced by my local trusted INDI.

BINGO!

You can buy a pump from Neo Bros a few hundred cheaper than main dealer prices if that helps.

 

[Mekkman]

Until I had the High Pressure Fuel Pump replaced I was faced with every possible type of hesitation/misfire etc,non of which had been identified by the main dealers ,the fault codes (as always) sending them on a wild goose chase.

Timing chain,coil packs,plugs,battery,thermostat,we're all replaced as being the culprits but did not fully solve the problems,until the HPFP was replaced by my local trusted INDI.

BINGO!

You can buy a pump from Neo Bros a few hundred cheaper than main dealer prices if that helps.

Thanks wilsofar, can you tell me more about your symptoms please did it missfire on the same cylinder (no1 in my case)?

 

[wilsofar]

I'm afraid my recollection of the whole episode is rather tainted by what Peugeot kept telling me needed replacing.
Not having a code reader at the time I did not keep any record of codes from Peugeot.

Oil leak being a precursor to replacing timing chain (within 20k of the last replacement!).The engine management light would activate on a slight misfire but would run ok even with the light on.

Unfortunately I can't identify the problems in chronological order.

From memory ,EM Light would activate
Engine fan would continue for 5 minutes after turning off.

Temperature guage would act normally -rock steady at 90.

Timing chain replaced - symptoms cleared only briefly.

Took the car to my usual Indi garage who read the codes and replaced the thermostat which solved the
fan problem.

We replaced the battery (known unusual code activater)and plugs and coil packs,still intermittent EML.

Finally replaced the HPFP and that solved the problems.

I honestly feel that if that had been done first then that would have negated all these subsequent repairs,although I can't know that for certain.

Whatever codes come up you must take them as only a slight clue as to what is in fact the real problem.

Sorry I can't be more precise,except to say that the HPFP doesn't last for ever so it's probably worth changing.

 

[Mekkman]

Many thanks indeed Wilsofar, you've described the symptoms almost identically right down to the cooling fan staying on for five minutes after the car stops. The only difference is that the miss fire is always on cylinder 1 and continues until the engine stops and is restarted. Like you said, I'm now viewing the codes as second and even third stage indicators so I think I need to get the HPFL tested asap. Would you be so kind as to clarify, did you replace the thermostat, temperature sensor or both?

 

[neilgsxr69]

As far as HP fuel pump and misfire goes I was told by a Peugeot technician that when the pump starts to fail it always shows as a misfire on cylinder 4 now I’m not sure if you’ve got the correct firing sequence and I know the same engine in the mini cooper S is taken the opposite way round cylinder 1 being cylinder 4, don’t ask me why they just are obviously to confuse :crazy:
Anyway looks like the next step to try, good luck let us know how you get on

 

[pete.garratt]

Sounds like either a wiring fault or a low level intermittent hpfp issue?

 

[Mekkman]

Does anybody know how to test the fuel pump please?

 

[pete.garratt]

You really need a logging OBD tool.

Clear the codes, go for a drive while logging the data, Hope the issue reoccurs, analyse the logged data.


Fuel rail pressure is logged, so you can graph it.

This is how I found mine.

 

[Mekkman]

Well, apologies for the delay in getting back to this thread but for various reasons the repair went onto the back boiler If somebody could tell this old technomong how to post a photo then I can share my weekend discovery with you all.

Thanks
Alan.