Slight misfire, no eml...

[PP200t]

Hi all.
The shed I've just bought has got a misfire, which is not setting off the eml (it is working, checked at ignition turn on)
I was looking yesterday and noticed the exhaust has a leak at cat joint and also at back box joint (pattern exhaust)
I checked all leads were on the coil right and pulled one off (lower right as looking at engine) with the engine running and there was no spark initially, then it started sparking. Could that be a coil fault?
2002 Clio 172.

 

[PP200t]

Can anyone help please?

 

[bloke]

get it plugged in and look at live data. exhaust blow precat or post?

 

[PP200t]

.

 

[PP200t]

get it plugged in and look at live data. exhaust blow precat or post?

After the cat at the joint with the exhaust the blow is.
There are no lights on the dash though, so doubt codes would show up? Would it be worth trying a coilpack?

 

[bloke]

if you want to chuck parts at it then go for it but chances are you'll end up wasting money. need to get it plugged in, check for any codes, clear them, run it for 20 miles or so, plug back in and look at live data.

 

[PP200t]

Right ok. I'll have a look for a code reader. Problem is every specialist is miles from me.

 

[oVerboost.]

Get a cheap code reader of ebay, the one I bought has paid for itself about 10 times over on various cars I've had any friend's cars.

I would also get the exhaust blow fixed, as although the post-cat lambda doesn't really do much it may well be causing odd readings for the ECU. When was it last serviced?

I'd recommend getting it scanned first, if that shows up nothing it could be something simple like plugs/leads/coil pack, could be a lambda although that SHOULD put a light on or worse case scenario which is unlikely, an valve could be at fault inside the engine - but like I say, thats an extreme scenario!

 

[PP200t]

Get a cheap code reader of ebay, the one I bought has paid for itself about 10 times over on various cars I've had any friend's cars.

I would also get the exhaust blow fixed, as although the post-cat lambda doesn't really do much it may well be causing odd readings for the ECU. When was it last serviced?

I'd recommend getting it scanned first, if that shows up nothing it could be something simple like plugs/leads/coil pack, could be a lambda although that SHOULD put a light on or worse case scenario which is unlikely, an valve could be at fault inside the engine - but like I say, thats an extreme scenario!

Thank you. I'll get one ordered now. Do you have a link to the one you bought?
I'll sort the blow out asap and get the code reader and go from there.
Fingers crossed it's not a valve gone.

 

[oVerboost.]

I don't have a link I'm afraid as I bought it about 6 years ago. In fact, the one I have doesn't even have Renault listed in the menu but it finds it through the "Other" option.

Another option, if you have an android phone is to download the torque app and use a bluetooth OBD adapter, this can also check for codes/turn out lights etc.

 

[PP200t]

Ah bloody hell, I think I've got one of those somewhere. I'll have a look. Thank you!!

 

[bloke]

right...torque is crap, plain and simple. it will miss plenty of codes and misread them as well. i had a car in that showed no codes on it, basic autel reader brought up 12 codes.

if you want to buy a good all rounder get one of these...http://www.ebay.co.uk/itm/Autel-Max...305656?hash=item3f5b9315b8:g:5UcAAOSwnLdWq7v-.
you'll probably get it cheaper but that was the first one i found on fleabay. i've got one i use for a quick read and live data and the only time it's let me down is on older jaguars.

re faulty lambdas the last half a dozen or so i've had to replace haven't brought a lambda fault up. couple have brought a fault up but not lambda even when read on clip, it's only when you look at live data you see what's happening.

 

[JB21]

Could be an injector, does it sound/feel like it's running on 3?

 

[jamesycc]

if you remove one ht at time and one isn't sparking/arching then that may be your problem. Had a coilpack go on me with similar symptoms, lost all power to cylinder 3. They are prone to failing when they get old. If they're all sparking then it could be either the ht lead, plug or injector. Lambda sensor can throw a misfire if its worn out and sending the engine management wrong info. I had an injector fail on me but was a bugger trying to get a fault code, had to scan on the move and wait for the misfire to kick in.

 

[PP200t]

if you remove one ht at time and one isn't sparking/arching then that may be your problem. Had a coilpack go on me with similar symptoms, lost all power to cylinder 3. They are prone to failing when they get old. If they're all sparking then it could be either the ht lead, plug or injector. Lambda sensor can throw a misfire if its worn out and sending the engine management wrong info. I had an injector fail on me but was a bugger trying to get a fault code, had to scan on the move and wait for the misfire to kick in.

Thank you for your suggestions. It drives and runs (doesn't stall) but when pulling away often it seems bogged down and wants to cut out (but doesn't) and when driving you can feel it missing and pulling back slightly. It's not spluttering as such, just not stable like it should be. (I know 1*2's run lumpy from cold)
Can you run the engine without the inlet on to remove the ht leads or do you mean remove from the coilpack?

 

[jamesycc]

Thank you for your suggestions. It drives and runs (doesn't stall) but when pulling away often it seems bogged down and wants to cut out (but doesn't) and when driving you can feel it missing and pulling back slightly. It's not spluttering as such, just not stable like it should be. (I know 1*2's run lumpy from cold)
Can you run the engine without the inlet on to remove the ht leads or do you mean remove from the coilpack?

Sounds like mine was before Xmas. I had one injector fail which gave me an obvious misfire. I unplugged the ht one at a time from the coilpack with it running to see if the engine sound changed. All 4 were firing but when I unplugged number 3 the engine note didn't change so I knew it was more than likely the injector had gone. I'd replaced the plugs recently so ruled them out and the ht's were only a year old from new so ruled that out too, plus I had a similar failure a year before.
It ran ok after id replaced the faulty injector but the running and idle were still a bit off. Had a spare set of 2nd hand injectors so tried another one and it sorted it. From what you've described I would say it might an injector or injectors wearing out. Cold idle is lumpy on these engines but mind was almost stalling at traffic lights and felt like it wasn't quite pulling right at speed, similar to your symptoms.

 

[jamesycc]

you can new magnetti marelli injectors off the ebay for £29.99 new posted by the way. Cheapest by alot, genuine oe replacements:smiley:

 

[PP200t]

Drove it tonight. Pulled on my drive and the revs shot up to 3k rpm and the electrical warning light (yellow with zig zag) came on. Throttle made no difference at all. Turned the car off and back on and it idled as before, lumpy but at normal speed.
Bloody heap of junk!!!

 

[Louis]

Coil pack mate. Get it changed over for the price.

 

[Louis]

Try giving the TDC sensor a clean too? That's free and simple.

 

[PP200t]

Thanks mate I'll have a look at that.

 

[PP200t]

Little update. With the engine running I unplugged individual ht leads from the coil, no change when removing 1, slight change with 2, definate change when pulling 3 and 4, car wanted to die. So from that I'm guessing the coilpack or leads are goosed? Sadly my quickly dispatched code autel code reader hasn't arrived quite so quickly so can't check error codes yet. But I'm thinking leads or coilpack as has been said above.

 

[bloke]

faulty leads or coilpack wont bring elec fault light on, also can't make revs rise. need to clean connectors under bonnet fuse box throttle pedal, body etc and get it plugged in.

don't just change things 'for the price' otherwise coilpack, leads, plugs and lambda will set you back around £210. chances are lambda is iffy and you've either got a bad connection or possibly loom issues.

 

[PP200t]

@bloke thanks mate. I've tired a coilpack with the help of @NorthloopCup but it made no difference. Also checked over my leads which although aftermarket appear ok.
Today the throttle had a mind of its own, first 4K then 6k revs and after that I have a engine management light on now. I'll get the codes read tomorrow hopefully and go from there. Fingers crossed I'll get it sorted soon.
Regretting this purchase so much right now!!

 

[bloke]

wouldn't trust aftermarket leads on them, not the cheap shoe lace eurocarparts ones by any chance?

 

[PP200t]

wouldn't trust aftermarket leads on them, not the cheap shoe lace eurocarparts ones by any chance?

I don't know to be honest, they are black ones but say performance leads on them. I'll plug it in to a code reader, see what happens then and if need be I can get leads.

 

[bloke]

check the leads aren't trapped under the plenum.

 

[PP200t]

I checked that tonight. Definately not trapped which is a plus I guess
Funny I was reading a thread about the peddle and then this happens today.

 

[bloke]

check and clean the connectors and see if it comes back.

 

[PP200t]

Silly question but what is best around the house to clean the connectors with please? I read wd40 but not sure.

 

[bloke]

contact cleaner, gt85 etc. if they aren't that bad.

for bad ones i use acid wheel cleaner, quick spray, leave for few seconds, neutralise and quick spray with gt85

 

[PP200t]

Right my code reader finally arrived today, plugged it in and it came up with two fault codes. Bearing in mind I have no eml on.
P0120 throttle/pedal position sensor switch
(Guessing this is from when it was revving itself the other day, I've cleaned that up and touch wood.....)
P0130 o2 sensor circuit bank 1 sensor 1
Am I correct in thinking the o2 sensor 1 would be the before cat lambda? Would swapping them round front to rear be a suggestion to see if it runs better?
Thanks in advance

 

[cs_dave]

Clear codes go for a drive 15 min try again switching lamdas is a option

Sent from my SM-G920F using Tapatalk

 

[PP200t]

Reset the code the other day, have driven about 60 miles over that time, still runs rough, with a petrol smell (running rich I think) poor mpg etc but no code has manifested itself again? I'm going to switch the lambdas around as soon as I get time to see if that cures it. I'm right in thinking that the rear lambda is just for emissions so it won't affect the running of I put the possibly faulty front lambda in the rear hole and visa versa?

 

[jamesycc]

nope, they're both the same. I did it with mine. I think its either 22 or 24 mm spanner needed. Sounds like its running rich if it petroly smelling, lots of inburnt fuel. Does it pop and bang when driving? Got a be either coilpack, ht's or lambda to run rich surely. Have you replaced anything yet??

 

[STEVE.M]

nope, they're both the same. I did it with mine. I think its either 22 or 24 mm spanner needed. Sounds like its running rich if it petroly smelling, lots of inburnt fuel. Does it pop and bang when driving? Got a be either coilpack, ht's or lambda to run rich surely. Have you replaced anything yet??

See Post 24!

 

[STEVE.M]

Reset the code the other day, have driven about 60 miles over that time, still runs rough, with a petrol smell (running rich I think) poor mpg etc but no code has manifested itself again? I'm going to switch the lambdas around as soon as I get time to see if that cures it. I'm right in thinking that the rear lambda is just for emissions so it won't affect the running of I put the possibly faulty front lambda in the rear hole and visa versa?

There is a big difference between running rich and unburnt fuel.
Doesn`t anyone start with basics any longer?
Plugs out, do a compression check.
Assuming compressions are good (180ps + ) & matched, replace the plugs if they are not NGK or need gaping.

 

[PP200t]

It doesn't pop or bang when driving it does idle poorly and there is a smell of petrol present initially after starting. Also it's drinking petrol like an alcoholic!! The reason I was going to swap lambdas around is the code on the code reader showing as sensor 1 fault. I know it's not the coilpack or leads I don't think as a known working coilpack swap made no difference. Unplugging injectors makes the engine run worse. It's less of a misfire thinking about it and more of a roughness with hesitation when driving, not a lot, but noticeable.
I don't have the equipment or knowledge to check compressions though.

 

[STEVE.M]

http://www.ebay.co.uk/itm/PETROL-EN...391968?hash=item2a338b4660:g:rNYAAOxyUylTVWJ6

Screw it in & turn the key,1 pot at a time.

 

[bloke]

There is a big difference between running rich and unburnt fuel.
Doesn`t anyone start with basics any longer?
Plugs out, do a compression check.
Assuming compressions are good (180ps + ) & matched, replace the plugs if they are not NGK or need gaping.

someone once had a faulty coilpack so i think 90% of people just suggest coilpack :wink: