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Fuel Injector stuck on Trophy



  Clio Trophy
Can anyone help me out and save my Christmas. I have already searched the forums and no one has had this problem of a stuck fuel injector that I can find.

I own a Clio Trophy 182 with 42k on the clock which has been well maintained by Fred (but now Fred has shut up shop) and its now running on three cylinders.

On my way to work the car just suddenly started to run on three cylinders and sounded like a chopper motorbike and the smell of fuel was really bad. Smoke started to come out the exhaust and the toxic fume warning light came on and off. I managed to turn the car around and head home.
I bought new Renault spark plugs and HT leads from Renault Wolverhampton/Autoworld and my mechanic changed them but it was still running on three cylinders. This was done on my driveway. He checked the coil pack and it was kicking out a good spark which lead us down the injector route.

We got the car picked up and driven to his workshop as I didn't want to drive the car incase I damaged the Catalytic convertor. My mechanic ruled out a dropped valve and he then connected it up to a diagnostic machine which told us it was Cylinder No. 2 fuel injector. He then found out that this injector was stuck on and constantly spraying fuel. It wasn't modulating or pulsing like it should do. This explained the strong smell of fuel and smoke. He believes it is the ECU or possibly the wiring loom. We undone the battery overnight to reset the ECU (which I think is how its done) but this didn't solve anything.

Two weeks before that the temperature sensor was replaced because the temperature gauge wasn't working now and again and when it was not working the engine was running rich and the car would eventually cut out because it was being over fuelled. The RAC was called out and he wobbled the temperature sensor and it came back to life and this solved the problem. This is a common fault apparently so my mechanic simply changed the temperature sensor for a new one and I put on a new battery because that what the RAC man recommended to do as it looked like the original battery and winter is coming. Everything was fine until two weeks later.

Has anyone had this problem and what is the best route to go down now. Tomorrow my mechanic is checking the wiring loom but is it easy to simply change the ECU and how much does a new ECU cost?

If I need a new ECU, then is it worth upgrading the ECU to an aftermarket product? The only modifications on the car is a ITG panel air filter, the latest Yozzasport exhaust from Fred and the Pure Motosport front strut brace and solid top mounts. Other than that its all stock but would an aftermarket ECU screw up all the lights on the dash board etc. I don't really want to deviate from how Renault originally wanted the engine to run and perform and as I use the car daily I don't want to fall down the dreaded route of having a unreliable car like some people have after modifying their cars too much

Please can anyone offer any advice
 
  big boost cup
Just chuck another injector in and go from there
It's also not a simple as chucking in another Ecu. I think you'd need to change the uch as well
 
  Clio Trophy
Sorry I should I forgot to say that we replaced the faulty fuel injector with a brand new one has this hasn't solved the problem
 

MarcB

ClioSport Club Member
  Too Many
A UCH is £216 from renault
A ECU is £399 from renault

You then need coding of the two units and also keys need done as ones keys have been coded you can't recode them
 
  182 Trophy
Hopefully there'll be a fault in the wiring loom that's easy to fix. There's always second hand ecu's on eBay complete with keys - there's no real need to buy new. You may also be able to get one from someone on this forum.

Hope you get it sorted
 
  Clio Trophy
For all that have replied to me, I thank you very much.

My mechanic has checked the loom and its all in good condition. He has checked and there is no short circuit to earth.

So it must be the ECU then, but how can an ECU just fail like this? I'm worried that if I spend the money to buy a new ECU and this doesn't fix it then I'm left with a dud car or a car that runs on three cylinders.

Also why do I need to buy a new UCH with the new ECU and get new keys done. If Renault were to do this, then I reckon that's £1000 spent easily. Why is Renault so expensive?

If I were to buy second hand ECU then what else do I need to buy and how do I tell if the second hand ECU is compatible. What happens if someone sells me an ECU for a 172 for example.

Also why is the KTR Sport Gen 90 a "plug and play" ECU compared to a standard ECU? It states on the K-Tec website that a new UCH isn't required with their ECU so why the f~#k would Renault design it like this? Also what is an UCH?

Would it be better for me to simply buy the Gen 90 ECU and simply plug it in without the hassle of buying a new UCH and getting the keys done and get it mapped at a later date

I now think all Clios and Renaults especially, are a pile of sh1t. The car has only done 42k and its been well maintained so I don't get how an ECU can fail like this.

So many questions, lol
 
  dan's cast offs.
very very rare for an ecu to fail. if you do want to change it then just go for a second hand set up and swap it over, ecu, uch, key etc.
 
  182 Trophy
Just a few things to recheck before going to buy a new ecu...
Was it definitely the right injector that was changed?
Does you mechanic have access to a noid light (it's a fast acting led that allows you to see injector pulse) or an oscilloscope. This will allow you to be certain that the ecu is at fault and not pulsing the injector properly.

It always pays to recheck before going down the expensive route of a new ecu etc.
 
  Clio Trophy
Thanks guys for your advice. I take it back about Clios. Just worried about shelling out money for it to still be broke.

I'll have to get it to Renault at Wolverhampton as Fred has gone now. Don't think my mechanic has got a noid light but he might have access to one.

I'll keep you posted as this is baffling me. A bit depressed as its my pride and joy
 
  PH2 172
Thanks guys for your advice. I take it back about Clios. Just worried about shelling out money for it to still be broke.

I'll have to get it to Renault at Wolverhampton as Fred has gone now. Don't think my mechanic has got a noid light but he might have access to one.

I'll keep you posted as this is baffling me. A bit depressed as its my pride and joy
I`d take it Mick in Long Eaton @MicKPM
 

MicKPM

ClioSport Trader
  Clio16v/Zoe Z.E.50
Genuine ECU failures are extremely rare but they do happen... Rarely!

A quick scope test will show exactly what is going off.
 

MicKPM

ClioSport Trader
  Clio16v/Zoe Z.E.50
He's gone back to working with Ferrari's... the rest of the specifics can be found on numerous topics.
 
  Clio Trophy
Well I thought I'd post an update on my Trophy and why it was running on three cylinders.

Its been a while because of Christmas and New Year but I managed to get the car to Mick at Diamond Motors. Thanks Dan@SJM and Steve for recommending Mick. Not met the man yet but what a bloke. He sure knows his stuff.

He has found the fault and gentlemen it was the ECU. I can't remember exactly what Mick said on the phone but a relay has failed causing the injector to earth and therefore continually spray fuel into the cylinder. So guys, an ECU can fail and that's why I writing this in case it happens to someone else. Mick said its extremely rare to happen but its fcukinhg happened to me lol. Anyway its hopefully not to bad. Should set me back around £200 to get the ECU fixed by a company specialising in repairing ECU's. So hopefully I won't need a new ECU and UCH and keys etc etc.

The only downside is the car is now blowing lots of white smoke, as Mick has the car running on a "vanilla" ECU (what ever that is), which it was doing whilst running on three cylinders. Mick is draining the exhaust as there was a shed load of petrol in the exhaust and he didn't want to drive it with a pipe full of fuel and fuel vapour. Hopefully this is the cause of the white smoke. The extreme scenario is it could be a fcuked cylinder caused from over fuelling the cylinder and causing bore wash, but I didn't drive the car no longer than a mile or two to get the car home when the car started to run on three cylinders. So hopefully the smoke is due to excess fuel in the exhaust. Fingers crossed. Mick's doing a compression test just in case there is a problem. However I might also have a scrapped CAT.

Anyway I'd thought I would post to update everyone just in case some one else has a similar problem in the future as its annoying to search and find a similar thread only to find out there was no conclusion at the end of the thread.

So ECU's can fail but its extremely rare.
 


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