Misfire 172 tried lots Still There !!

[KLUNK]

i have previously posted on another thread, but thought this was worthy of its own as it may help other as well.

What started as a slight misfire issue a few weeks ago has developed as such...

Slight intermittent misfire, codes pulled as coil fault multiple misfires. Searched on here and other places and found that HT leads can go bad, bought some 8mm high quality ones. though had solved it,


A few days later it returned, slight still driveable and felt like only missing one one cylinder. If i turn the car off and on again it will be fine for a random period then slight miss again.

Bought pattern coil from GSF, same result as above fine for a few days then back to above.

Hardly used the car since, but when i did it seemed fine, powerful and good on fuel with slight intermittent miss, like some days it would others it wouldn't

Suddenly it just died on me and when restarted felt like was missing on two cylinders, bought and fitted proper ngk plugs (took denso out) and still like above.

now it isn't intermittent and hardly runs.

Took injectors off, all seem to be spraying well none look particularly bad, all test 15 ohms using multimeter.

Cleaned Map still the same. Unplug map - car dies.

Unplug injector 2 and 3 car runs the same i.e. terrible.

unplug injector 1 and car dies

am stuck now any suggestions greatfully received !!!

 

[bengtt5]

tdc sensor...........

 

[KLUNK]

tdc sensor...........

thanks for the reply

i took that off as well and cleaned it using carb cleaner and a light abrasive until shiny

could it faulty? not sure if it has any electronics in it. think its the next thing to buy tho !

 

[bengtt5]

cheap enough to replace causes all sorts of probs

 

[JackJack]

Tdc sensor can fail. I would of fitted a genuine coil pack only patterns tend to be rubbish.

 

[KLUNK]

Tdc sensor can fail. I would of fitted a genuine coil pack only patterns tend to be rubbish.

I know what you mean bout pattern parts but searched plenty and no one had any probs with pattern coils.

Tdc next !

Any other potential causes spring to mind ?

 

[imprezaworks]

Like allready said, tdc sensor or maybe o2 sensor? Oh and is your car std?

Dan.

 

[KLUNK]

Car standard.

Got any decent prices on o2 or tdc sensor ?

Cheers for the replies

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[imprezaworks]

I havent mate sorry. For the cost from Renault just get a new tdc sensor, then you know thats one thing it may or may not be.

Dan.

 

[KLUNK]

Yep can't argue with that

Will go Monday

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[JackJack]

http://www.renaultpartsdirect.co.uk...category_id=51&option=com_virtuemart&Itemid=1

 

[KLUNK]

thanks jackjack can't seem to find a map sensor on there as may get one of those but reno want 120 !

 

[KLUNK]

also, all of the plugs i took out were sooty, not the brown colour you wold want.

this to me indicated a more 'global' fuel or spark issue, as opposed to a more 'local' issue with a particular cylinder

 

[olliewebbuk]

http://www.renaultpartsdirect.co.uk...category_id=51&option=com_virtuemart&Itemid=1

Yeah, except that's for a 1.2 16v Clio. Not a 172.

 

[barnesautos]

also, all of the plugs i took out were sooty, not the brown colour you wold want.

this to me indicated a more 'global' fuel or spark issue, as opposed to a more 'local' issue with a particular cylinder

Have you had you're fuel pressure checked? Causes misfiring coz of under pressure (weak mixture) and over pressure (rich mixture) sooty plugs , just a thought

 

[KLUNK]

Haven't had fuel pressure checked.

Car pretty much undriveable so can't really get to a garage.

I'm focussing more on electrical due to the on/off nature of the original misfire

Thanks fir the spot on the tdc sensor !

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[MicKPM]

Okay, lets start simple and work on the ignition system only at this point:

• Go back to the original plugs that it seemed to run on - Does it work again?
• Compression Test - Results good or bad?
• Continuity check trigger lines from ECM to Coil Pack and/or Scope ignition drivers - All okay?

Mick

 

[KLUNK]

Okay, lets start simple and work on the ignition system only at this point:

• Go back to the original plugs that it seemed to run on - Does it work again?
• Compression Test - Results good or bad?
• Continuity check trigger lines from ECM to Coil Pack and/or Scope ignition drivers - All okay?

Mick

tried old plugs again yesterday after new ones made no difference. still misfiring.
compression tester bought and en route will conduct test as soon as arrives
i have no idea how to do this last one !! happy to follow directions tho !

 

[Iceberg_172]

Sorry when you said you unplugged injectors 2 and 3 and the car kept running crap. Doesnt that mean an injector fault? Or am i being silly

 

[KLUNK]

Sorry when you said you unplugged injectors 2 and 3 and the car kept running crap. Doesnt that mean an injector fault? Or am i being silly

not sure, that is why i unplugged them to find out. but then they tested the same on the mutlimeter and all seemed to spray fine when i removed them, and none looked dirty or gummed up.

could be that they are not right but i have no clue really.

really appreciate these replies, determined to sort this. having read alot of posts where people have misfires, they don't seem to update with the fix once sorted, the thread just seems to die...

 

[Iceberg_172]

If you say the car runs crap, when you unplug the injectors and it stays the same then thats your issue.

I had this same problem aswell. Intermittent then started happening all the time.

Swap it around with one that works, then unplug them and see, so swap 2 with 1. Unplug 2 and if its an injector problem the car will struggle. The faulty injector willthen be in "1" postion. To clarify, unplug it and nothing will change

 

[KLUNK]

If you say the car runs crap, when you unplug the injectors and it stays the same then thats your issue.

I had this same problem aswell. Intermittent then started happening all the time.

Swap it around with one that works, then unplug them and see, so swap 2 with 1. Unplug 2 and if its an injector problem the car will struggle. The faulty injector willthen be in "1" postion. To clarify, unplug it and nothing will change

yep, can't believe i didn't do that when i was in there, must be down to frustration.

thanks i will do that tonight weather permitting.

k

 

[imprezaworks]

Out of interest, do you ever let it run low on fuel? Mine gets pissed off when i let it go low.


Dan

 

[KLUNK]

Out of interest, do you ever let it run low on fuel? Mine gets pissed off when i let it go low.


Dan

not as a rule mate.

it will have been pretty low at stages but nothing recently i can put my finger on.

just been reading through other misfire threads, so many of them end with no final fix or identified fault, really frustrating...

 

[Kyle.]

Mine was the same, it turned out to be the injectors so i bought some second hand ones. This cured it, but overtime it can back due to a faulty lead and an injector getting broke. Ive changed the plugs again as they were dirty and ordered some new leads just to be safe.

The biggest mistake was buying second hand injectors, ive found a place that will clean and test them for £56 posted and returned so im going to do that.

 

[KLUNK]

Mine was the same, it turned out to be the injectors so i bought some second hand ones. This cured it, but overtime it can back due to a faulty lead and an injector getting broke. Ive changed the plugs again as they were dirty and ordered some new leads just to be safe.

The biggest mistake was buying second hand injectors, ive found a place that will clean and test them for £56 posted and returned so im going to do that.

thanks for the reply kyle,

pretty sure its the injectors, i just swapped 1 with 2 and 3 with 4 hoping the fault would follow and guess what...

the car now runs like a bloody dream!!!!

sure it son't last but i took it for a ten minute run and put some fuel in as well so at least i know the fuel is clean.

incidentally the fuel in the fuel rail was crystal clear and clean.

interestingly the end of the fuel rail near the air box looks like it should have a rubber pipe plugged onto it, but mine hasn't, also there looks like there could be a diaphragm near it but this is also blank...

where are you looking for your injector clean etc?

also do they guarantee to fix them or is that on top?

 

[KLUNK]

i now have new leads, plugs and a coil.

cleaned the map and the tdc (also have a used map on it's way to see if that makes a difference)

can't imagine what else it can be, or is that a bit naive?

 

[KLUNK]

is it here?

http://injectortune.co.uk/Injector_Cleaning.html

i'm wondering if they can test and repair an electronic issue?

might just buy two new ones if it starts missing again and it's on either 1 or 4 which means its followed the injectors..

 

[Kyle.]

Yes mate thats the place!

The end of the fuel rail should look that its fine.

 

[KLUNK]

right, another update.

took it out, ran fine and fast for half an hour, thought (maybe it's sorted) illogical i know.

put a load of fuel in, pulled out of the petrol station and BAM! runs like crap.

limped home, pulled up the drive, popped bonnet unplugged injector 1 (no difference) unplugged injector 4 (no difference)

unplugged 2 car died.


BINGO 2 failed injectors.

Surely this is the problem diagnosed now.

Will order 2 from here tomorrow

http://www.ebay.co.uk/itm/Renault-Clio-Sport-172-182-2-0-16v-Fuel-Injector-NEW-/170600428767?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item27b893f4df#ht_677wt_932

thanks for all the replies, i will update if this does actually sort the issue but am confident now.

 

[Iceberg_172]

well done. did you swap the injectors with others though? might be the circuits (wiring)

just mentioning before you buy injectors

 

[KLUNK]

well done. did you swap the injectors with others though? might be the circuits (wiring)

just mentioning before you buy injectors

before you posted about swapping them, 2 and 3 were the ones where unplugging them made no difference.

i swapped 1 with 2 and 3 with 4, so the suspect injectors were now at position 1 and 4.

after this the car ran fine for half an hour.

As soon as it started missing (badly) i pulled over and unplugged 1 and then 4. no difference. unplugged 2 car died.

so the fault has followed the suspect injectors.

Thanks for your help btw i had missed that about swapping injectors.



unless i am missing something re the wiring? i bloody hope not !!

 

[Iceberg_172]

Nah mate your right. wirings fine. deffo injector problem. I found it ran fine sometimes after i played around with them then the fault would come back later

You should be sorted once you put replacments in

 

[KLUNK]

Great stuff.

Thanks again

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[KLUNK]

FFS !

Brand new marelli injectors fitted on 1 and 4.

Ran fine for ten seconds..

Then bam missing on 1 and 4 again.


Back to basixs

Any ideas ? Was mention of trigger points etc how do I do this ?
Any guides out there ?

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[MicKPM]

Yep, time to start looking at wiring faults now... scope the trigger lines if you have access to one but I doubt you will as they're not everyday DIYer bits of kit (They start at around £700 and go up to £4k). If you don't have access to a scope you will first need to confirm that each injector has got a good +12v feed. I know you've checked that they're all 'spraying' but that doesn't confirm a stable voltage. Then check the wiring continuity between each multi-plug and the ECM (Bare in mind the +12v is 'common' to all x4 jets and the 'triggered' earths are wired for batch firing so 1/4 and 2/3 will have common lines).

Where are you based mate? If you could get the car to me I'd gladly take a look at it and nail this demon for you.

Mick

 

[MicKPM]

Another thought, has anyone checked the fuel pressure yet?

 

[KLUNK]

hi

thanks for the replies.

im in warrington so a fair distance from you mate.

looking like a specialist, only problem is i don't want to drive it as it is.

Is there a common issue with these and corroding / chaffed ecu loom? where would i look for that?

and no not checked the fuel pressue as i don't have the equipment. i migyt be diy'd out at this point

 

[KLUNK]

also how would i check the triggered earths etc is there a wiring diagram i can refer to ?

i only have a basic multimeter but can buy equipmemt if not too expensive ...

 

[MicKPM]

IF your multimeter has a diode or continuity test mode then it'll help trace the wires from point A to B. I don't have access to my wiring schematics at the minute i'm afraid as my tablet is locked away in the workshop but they're likely to be on here somewhere already (Search?)

There's no obvious faults with 172/182 wiring looms i'm afraid. The only thing you can do is visually inspect each plug for signs of damage.

Mick