ClioSport.net

Register a free account today to become a member!
Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Really feint hesitation/miss at light throttle



  Titanium ph1 turbo
@jinjur did you ever fix this issue? I have the exact same problem going on right now...

Revs intermittently bounce between 600 and 1200 on idle, almost cutting out then it takes a breath and bounces back up... other times it will idle fine at a solid 750....

When driving, slight hesitation on light load.. sometimes drives fine, sometimes its there a lot...

Have so far changed lambda, injectors, map sensor, cambelt just changed and timing all set...

I’m suspecting maybe the fuel system.. pump, filters, regulator?....
 
  2003 Clio 172
Never fixed fella.

There are 2 things i didn't change and that was throttle body and plug leads so don't know if that is available to you to do.

You are a phase 1 thought right with a cable operated tb, turbo?

Its a real pig to drive because of this, car idling fine at lights for example and when i go to set off i press the pedal and the revs drop initially. This usually results in a stall :(

I replaced loads to try and address the issue, coil pack, plugs, fuel filter, injectors, crank sensor, both lambda sensors, swapped a map sensor with simon....no change

I also checked the timing and it is on the button

J
 
  2003 Clio 172
Bit of a reach I know..................but could plug leads be a contributing factor to this?

I can certainly understand how they might break down and cause hesitations and misfires etc, but with regards to my initial issue (push the pedal and revs drop) has anyone else noticed a benefit from changing leads? I am sure that after nearly 20 years they are bound to be tired.

Am i missing any sensors or anything? Air temp? Knock? I swapped MAP with Simon and saw no change.

I also recall an issue with my car waaaaaaaaaaaaaaaaaaaaaaaay back when i got it and stupidly power washed the engine and made a poor job of covering the tb. Back then the car had a hissy fit and idled at like 4k rpm but after a day of drying all seemed to be well.

Could this be corrosion or something in the tb from that event?

J
 
  Clio 172 Ph2
Bit of a reach I know..................but could plug leads be a contributing factor to this?

I can certainly understand how they might break down and cause hesitations and misfires etc, but with regards to my initial issue (push the pedal and revs drop) has anyone else noticed a benefit from changing leads? I am sure that after nearly 20 years they are bound to be tired.

Am i missing any sensors or anything? Air temp? Knock? I swapped MAP with Simon and saw no change.

I also recall an issue with my car waaaaaaaaaaaaaaaaaaaaaaaay back when i got it and stupidly power washed the engine and made a poor job of covering the tb. Back then the car had a hissy fit and idled at like 4k rpm but after a day of drying all seemed to be well.

Could this be corrosion or something in the tb from that event?

J

I had a misfire on my 172 ph2 52plate and all it was, was the lead from the coil pack to the plug in question (far right as you stand at the front of the car, Piston1?) the lead was crimped under the air intake manifold and caused arcing.

Now this may not be the same in your case but i assumed it would be the coil and and replaced it but didnt replace the leads until i resurrected the car summer last year (after nearly a decade in storage)

Have you changed plugs and leads at all?
 
  Clio 172 Ph2
Hey bud, plugs, coil, injectors, crank sensor..............lots of stuff. Just not the leads


Im currently running a set of leads from CES car parts in my local area.

Euro car parts also sell them.

Could be £30 well spent if you try them and they work could always upgrade to a better set later down the road?
 
  2003 Clio 172
Its a fair point buddy. Found a Cambiare branded set today for like 20 quid and it might be worth it for a test.

Anyone know if that is an ok brand? Never heard of them myself

J
 
  2003 Clio 172
Your mileage is quite simply filthy............you lucky git :)

Managed to use a wee code today to get the leads for 22 quid which is great and well worth a punt.

Have been having some crazy smells from the exhaust that just scream cat and the car is popping HUGELY on overrun..............don't get me wrong, i love it but never wanted it. I think the car is not sparking fully and some of the fuel is getting into the cat/exhaust and igniting.............great for spectators and none of this "pops and bangs" artificial sounding malarkey. Sounds proper. lol
 
  Clio 172 Ph2
Your mileage is quite simply filthy............you lucky git :)

Managed to use a wee code today to get the leads for 22 quid which is great and well worth a punt.

Have been having some crazy smells from the exhaust that just scream cat and the car is popping HUGELY on overrun..............don't get me wrong, i love it but never wanted it. I think the car is not sparking fully and some of the fuel is getting into the cat/exhaust and igniting.............great for spectators and none of this "pops and bangs" artificial sounding malarkey. Sounds proper. lol

Ive owned the car since Feb 2009, During the first 12 months it had dephaser cambelt aux belt and a service which cost a fair bit with the dealer.

fast forward to January 2011 and she can began missfiring. the mrs and i were 3 months away from our first child being born, id also had to spend on new CAT and coil pack a few months earlier and basically s**t myself at what the next cost was going to be.

So i garaged her at my mums house and took out the Peugeot 206 instead and ran that for almost a decade lol.


So shes been sitting in a garage collecting dust since lol.


Brought her back out August 2019 and fixed any issues that arose from standing such as discs, alternator, new battery, Coil Pack and leads etc.

Turns out the missfire was a crimped HT lead anyway and would have only cost me £30 to fix at the time, but with what i had spent on her within the first 12 months of ownership i just thought "what now!" lol


So now as luck would have it i have a seriously low mileage example of a standard 172 lol



Keep me posted if the leads do the trick, if shes running rich and injecting too much fuel could possibly be a Pre cat Lambda causing some of your issue with over fueling.



Jon
 
  2003 Clio 172
Ach ffs............reserved leads with the code above and went down.

Was given a box of Pro-Spark plugs which looked shocking (pun) quality..............add the fact that one of them was an old and used NGK lead (FLOL!) I just refunded them. While it might have helped diagnose the issue, not a fan of putting pure shat in

All in all. Marvellous day so far

:D
 
  Clio 172 Ph2
Ach ffs............reserved leads with the code above and went down.

Was given a box of Pro-Spark plugs which looked shocking (pun) quality..............add the fact that one of them was an old and used NGK lead (FLOL!) I just refunded them. While it might have helped diagnose the issue, not a fan of putting pure shat in

All in all. Marvellous day so far

:D


Fully agree......

Dont need to be putting any used leads on unless you know they're fault free!


Let me know how you get on as i do have 3 spare HT leads that are still fully operational and a spare coil pack if you need to check anything.


jon
 
  2003 Clio 172
Cheers bud. Appreciate that.

I was hoping to completely rule out coil pack/plugs/injectors and up stream O2 as these were all replaced with brand new and the symptoms didn't change.

I can't think of much else that would effect the running in this manner apart from plug leads and perhaps the throttle body.

One thing i never did replace was the inlet manifold gasket which is old and brittle but I thought an air leak would cause different kinds of symptoms
 
  Clio 172 Ph2
Cheers bud. Appreciate that.

I was hoping to completely rule out coil pack/plugs/injectors and up stream O2 as these were all replaced with brand new and the symptoms didn't change.

I can't think of much else that would effect the running in this manner apart from plug leads and perhaps the throttle body.

One thing i never did replace was the inlet manifold gasket which is old and brittle but I thought an air leak would cause different kinds of symptoms


Like i said there are 3 working HT leads at my mums house (my working garage lol) that i could happily send to you to try..


Not sure which cylinder it is but the lead that goes to the furthest cylinder closest to the Passenger side of the car is the one that got crimped for me so that is a none working lead and as such ended up in the scrap bin.


But i do have the leads for the other 3 cylinders from the CAMBELT side counting 123.

Sods law would definately dictate though that if you do have a HT lead problem its gonna be the one lead i dont have spare lol
 
  2003 Clio 172
Did you have a permanently missing cylinder or was it just in certain situations?

See mine idles lumpy as frig (despite having the Henk map with raised idle) and only hesitates in certain driving situations. Flat to the mat it pulls real strong with no missing or ignition breakdown. But, say I am a bit low in rpm for the gear it bogs right down and then gets to around 2-3k and just lights up.

J
 
  Clio 172 Ph2
Did you have a permanently missing cylinder or was it just in certain situations?

See mine idles lumpy as frig (despite having the Henk map with raised idle) and only hesitates in certain driving situations. Flat to the mat it pulls real strong with no missing or ignition breakdown. But, say I am a bit low in rpm for the gear it bogs right down and then gets to around 2-3k and just lights up.

J

I had a constant missfire caused by a crimped HT lead that was arcing and causing the plug to not fire correctly and thus making the cylinder miss constantly. Sounded like a tractor lol.


when its cold mine is lumply idle (no remap) but doesnt miss or anything when you apply throttle.


J
 
  Clio 172 Ph2
Did you have a permanently missing cylinder or was it just in certain situations?

See mine idles lumpy as frig (despite having the Henk map with raised idle) and only hesitates in certain driving situations. Flat to the mat it pulls real strong with no missing or ignition breakdown. But, say I am a bit low in rpm for the gear it bogs right down and then gets to around 2-3k and just lights up.

J


With this in mind i would also look at the Air intake manifold gasket you mentioned.

If shes sucking too much air in through a gap in the gasket it could possible cause a miss in power etc
 
  2003 Clio 172
Right...........still suffering this. In fact, it's really starting to bog down quite a bit lately.....p'raps the colder mornings or whatnot but anyway.................could this car really be over fuelling? Or could it just be under igniting?

Do fuel pressure regulators fail on these? Do they have them? I remember my old civic had a mare of an issue that ended up being the fpr but symptoms were not the same

Also, coincidence or not.............i have had to clear the code for what i think is the rear O2 sensor a few times in the past week. O2's were both replaced with new not even a year ago now and I never thought that the rear O2 did much apart from verify that the car had a cat.

Screenshot_20200205-175238_Torque (Lite).jpg Screenshot_20200205-175257_Torque (Lite).jpg
 
  Clio 172 Ph2
Right...........still suffering this. In fact, it's really starting to bog down quite a bit lately.....p'raps the colder mornings or whatnot but anyway.................could this car really be over fuelling? Or could it just be under igniting?

Do fuel pressure regulators fail on these? Do they have them? I remember my old civic had a mare of an issue that ended up being the fpr but symptoms were not the same

Also, coincidence or not.............i have had to clear the code for what i think is the rear O2 sensor a few times in the past week. O2's were both replaced with new not even a year ago now and I never thought that the rear O2 did much apart from verify that the car had a cat.

View attachment 1453221 View attachment 1453220

Personally im all out of ideas now other than asking someone with the Renault Clip to do a proper diagnostic test on the entire running of the engine to ascertain exactly where the issue is coming from and then subsequently diagnosing based on parts that work in that area.


someone has mentioned on here before about after an O2 sensor is replaced or injectors are replaced that the car fueling system can benfit from a reset of the fuel injection system done through the clip so that it can relearn the O2 sensors and readjust fueling ratios etc as it learns them.



Just another thought. if i find the exact thread where its mentioned i will copy the link and paste it in here for you.
 
  2003 Clio 172
Are. You. Kidding. Me. Louis?

I have been to 2 "specialists" in Northern Ireland. Let me tell you something about our specialists................they are turd.

So until the DUP get our bridge built across to the mainland then it is going to involve a boat trip.
 

Louis

ClioSport Club Member
Are. You. Kidding. Me. Louis?

I have been to 2 "specialists" in Northern Ireland. Let me tell you something about our specialists................they are turd.

So until the DUP get our bridge built across to the mainland then it is going to involve a boat trip.
Theres just a sense of going round in circles here
 
  2003 Clio 172
Theres just a sense of going round in circles here
That's not really helpful Louis.


I am trying to fix this myself............as an enthusiast..........and I am trying to learn.

Yes, a certain degree of parts cannon firing did happen based on sure thing fixes (injectors, coil pack, lambda etc)..........none of them worked. Which IMO is quite an important point in itself. So this is something quirky that I would like to understand.

I also clambered through the timing process, buying the correct tools to do so, learning as I went......making sure it was all perfect. Again, as timing was a big red flag. not in this case.

This car is worth, what.........maybe a grand? So the whole idea is that I can try and look after and fix what I can.

If it was a show queen with maybe 30k on it then for sure, it would be on the boat to Mick or someone, but its not.

Its my little workhorse that I would be stoked if I could fix.



This would be a WICK forum if every single "can you help me......." thread was terminated with "go to a specialist".
 
  2003 Clio 172
FYI. Charles Hurst took 3 days to do the timing first time.

It was wrong.

They had to do it again, took another 2 days.






It was wrong.

I gave up.

They gave me money back.



I (quite madly) a few years later then asked them to investigate for me the poor running. The found nothing but told me i needed new rear brakes and tyres and thanks for the £80.



I don't want to name any others but 2 further Renault "specialists" i visited in the province with CLIP..............didn't have CLIP.

One didn't know what it was.


The same one just, and I quote............"only needs the one cam locking tool to do the belt, doesn't need all 3"




So.


There is that
 
  Clio 172 Ph2
FYI. Charles Hurst took 3 days to do the timing first time.

It was wrong.

They had to do it again, took another 2 days.






It was wrong.

I gave up.

They gave me money back.



I (quite madly) a few years later then asked them to investigate for me the poor running. The found nothing but told me i needed new rear brakes and tyres and thanks for the £80.



I don't want to name any others but 2 further Renault "specialists" i visited in the province with CLIP..............didn't have CLIP.

One didn't know what it was.


The same one just, and I quote............"only needs the one cam locking tool to do the belt, doesn't need all 3"




So.


There is that

No problem was just seeing if youd tried them.

In this instance i am all out of ideas.


other than replacing the intake manifold gasket and checking for any further leaks etc within the air intake system i have no further ideas for you sorry.
 

Martin_172

ClioSport Club Member
to save loads of reading, stick an updated summary post with everything you have changed so far so we can see what's left and see if we can get to the bottom of it
 
  2003 Clio 172
Hey @Martin_172 that seems like a sensible approach.

Ok, quick tidbit. Car has this weekend taken me around 120 miles on a trip to meet the fam without any issue. Returned a tidy 35 mpg although plenty of huge bangs and lots of bogging down so that is likely not accurate.

Also, went to start it tonight to make sure it was good for the run home and the dash threw lights.....the wee zig zag, service and the dsc light. The pedal would not rev the engine.....idled at 2k.

Turned off and on and all lights went out and the car behaved.

Usual symptoms:
Hunting idle, especially after pulling up to lights etc
Stalls frequently
Press the acc pedal from stand still usually drops revs to a stall
Low rpm higher gear bogging down, almost feels like over fuelling and then goes
Cat smells different almost every day
Exhaust sound to be extremely hot (cracking and chinking for ages after turned off)
Lots (lots) of bangs on overrun
Also noted at say 70mph on the motorway at just enough throttle, it feels like it is surging

To summarise what has been done/changed

- timing checked and double checked again by me. Using genuine tools I found it to be slightly out so I sorted that, tools slide in freely now.
- new coil pack, plugs, injectors, fuel filter (there is one), front and rear Bosch o2 sensors, new cat to mani gasket, crank sensor and crank sensor loom fitted
- new intake manifold donut gasket fitted
- swapped map sensor with simon, no change
- car has rstuner 98 ron map on btw so used to have a much better idle
 
  2003 Clio 172
Update.

Drove the return 120 mile leg this morning and the car didn't miss a beat. Averaged a neat 34.9mpg rolling at motorway speeds.

Popped on Torque with the OBD connector to see if i could capture what might be throwing the rear O2 error that keeps cropping up but sods law, it didn't.

A few odd observations that might (or might not) be relevant.

I was always of the opinion that the rear O2 value should be pretty static however, I did notice it basically tracking the front O2 sensor for large stretches of the journey (particularly at m'way speeds). There are times when it was pinned at the top of its reading and times when it basically sat at 0 (or less)

Screenshot_20200210-091651_Torque (Lite).jpg

Appreciate that Torque isn't the best app for this (i mainly just use it for CEL codes) but it was all I keep in the car.

The car still seems super rich mind you.

Most wee villages that I bumbled through between motorways were graced with huge *THRAPS* from the exhaust on gear change etc. Remember, I have a CAT and no pops and bangs nonsense.

It also had that boggy feeling on slower stretches, say rolling up to a roundabout in 3rd and allowing the revs to go low (but not too low if you know what i mean, say 2k rpm) and pulling on round the round about the car spluttering, grumbling and then coming to life like an on/off switch.

Wasn't that harsh miss that ignition would cause that feels very binary and sharp but again, that's only my take.

J
 


Top