Help needed! Running Issues....

[LawrenceR]

Morning all,
So after a bit of advice, or more likely confirmation of what I suspect....

Clio 172 Cup, sounds like it's running on 3 cylinders, it wanted to stall and really struggled between 2-3000 rpm, then would pick up and go.

I had the injectors cleaned on one of the group buy threads, I put new o rings in when refitting, I've changed the plugs for the correct ones and fitted OEM new coil pack and leads....still sounds the same, however it is a little more driveable than when I last drove it. It seems to go through the revs OK, but still sounds like it's running on 3 and it is really down on power. it drives and it has some get up and go, but it's not as it should be....

So, do I next try the LAMDA sensors, will that make that much difference or do I run a compression test and confirm what I suspect?

Engine is stock, a phase 1 filter, stock exhaust...

Any thoughts?!

Many thanks from a pissed off, sad Cup owner, I've been looking forward to going for a drive in this for a while!!

 

[JamesBryan]

Just because the injectors have been cleaned i wouldn't rule them out yet.

Try running the car at idle and unplug the electrical connector off each injector one at a time. If it sounds worse and is nearly stalling, then that particular injector is ok. If then engine note doesn't change, that's your faulty one.

 

[LawrenceR]

Thanks @JamesBryan i followed your advice, I should have also done that but wasn't thinking straight.

No2 injector made no difference to the running, so this may be the offending item.

As I was halfway there I pulled off the plugs, No2 plug was black. I did a compression test, cylinder 1, 3 and 4 read 12 bar, cylinder 2 was at 14....so I think things may be looking bleak....!!

I'll have to source a new injector and go from there.

 

[JamesBryan]

Not sure what the compression should be, but i've got 190psi ish in my head. So that would make Cyl 2 fine and the other 3 quite low...

 

[bloke]

Probably duff injector. If it's not shutting off or even with misfire you get borewash and that drops the compression. Did you ha e injectors unplugged for the compression test?

 

[LawrenceR]

190psi is 13 bar, so a slight difference between cylinders.

I thought extra fuel in the barrel will increase compression, so this would lead to this higher compression test result.

I'll replace injector and go from there.

Cheers.

 

[bloke]

Nope, washes oil away and drops compression but don't read into compression results to much. Even 12 bar isn't anything to be worrying about, different testers can vary in readings.

If it's weak due to duff injector then it will run rich to try and compensate. The Clio ecu is dumb so fee things can be 'faulty' and not bring a code or light on.

 

[JamesBryan]

Need injectors unplugged for compression test mate.

 

[JamesBryan]

Nope, washes oil away and drops compression but don't read into compression results to much. Even 12 bar isn't anything to be worrying about, different testers can vary in readings.

If it's weak due to duff injector then it will run rich to try and compensate. The Clio ecu is dumb so fee things can be 'faulty' and not bring a code or light on.

Especially the cheap Gunson one.

 

[LawrenceR]

I had the fuel line disconnected, so should achieve the same results.

I picked up an injector from a well known European car part distributors... not an ideal replacement but they were the only ones who had one on the shelf.

Fitted and instantly sounds better and is instantly more responsive and idling better.

I'll run it up the bypass and hopefully I'll be smiling from ear to ear again!

Thanks all for the help.

 

[Amos91]

I had the fuel line disconnected, so should achieve the same results.

I picked up an injector from a well known European car part distributors... not an ideal replacement but they were the only ones who had one on the shelf.

Fitted and instantly sounds better and is instantly more responsive and idling better.

I'll run it up the bypass and hopefully I'll be smiling from ear to ear again!

Thanks all for the help.

If it the Euro car parts Magneti Marelli one then they are the genuine equivalent - same product different brand.

 

[JamesBryan]

What brand injector was it?

 

[LawrenceR]

@JamesBryan @Amos91 Yeah, it was an ECP Magneti Marelli and has done the trip, it was a blast driving it back home.

I've not had a chance to touch it for 9mths since I pushed it into the garage with its initial problems! My old man has changed all the parts for me and I was looking forward to jumping in it today and just driving it! I'm glad I can now do that!

 

[adamlstr]

I've not had a chance to touch it for 9mths since I pushed it into the garage with its initial problems!

😊 What was wrong with it?

 

[JamesBryan]

@JamesBryan @Amos91 Yeah, it was an ECP Magneti Marelli and has done the trip, it was a blast driving it back home.

I've not had a chance to touch it for 9mths since I pushed it into the garage with its initial problems! My old man has changed all the parts for me and I was looking forward to jumping in it today and just driving it! I'm glad I can now do that!

They are the genuine ones mate, just not in a renault box.

 

[LawrenceR]

Oh great, and half the price and stocked on the shelf than my local Renault dealers! Perfect!

Hi Adam, I suddenly experienced running problems with it as described at the start of my thread, I didn't have time to sort it before going away for work again. The old man changed parts over for me to try and cure the problem.

I ran it up a few months ago and it sounded like it was sorted, but the minute I fired it up and drove it out of the garage this morning, I knew all was not well! I think I was just fearing the worse and thought it may have dropped a valve or such.

I should have bitten the bullet and replaced all injectors a few months back, but it's sorted for now.

I still have the engine management light on, but for the moment it seems OK and I'm again, short on time to spend on it!

 

[adamlstr]

Oh great, and half the price and stocked on the shelf than my local Renault dealers! Perfect!

Hi Adam, I suddenly experienced running problems with it as described at the start of my thread, I didn't have time to sort it before going away for work again. The old man changed parts over for me to try and cure the problem.

I ran it up a few months ago and it sounded like it was sorted, but the minute I fired it up and drove it out of the garage this morning, I knew all was not well! I think I was just fearing the worse and thought it may have dropped a valve or such.

I should have bitten the bullet and replaced all injectors a few months back, but it's sorted for now.

I still have the engine management light on, but for the moment it seems OK and I'm again, short on time to spend on it!

Glad that in the end, it wasn't too serious. I was just thinking the coil pack can't be that old as I remember fitting a new one, but I think I changed it as far back as 2010 - and you've nearly had the car 2 years already!

 

[JamesBryan]

The light should go out after a while. If you scanned the code i bet it'd come up with a destructive misifire which brings the light on.

Just a warning to say the misfire could be killing your cat.

 

[LawrenceR]

Yes @adamlstr I've almost had it two years, I don't know where the time has gone! I'm ashamed to say since its MOT, which is up in 2 months, it's done just over 100 miles! I've not had the time!

Yep, light will go out, if my mate gets a minute, he'll plug it into his computer for me, but it will be fine for now!