Misfire, rough idle, no dash warnings!!!!!

[Markooo71]

Proud owner of misbehaving 225 seeks advice....
After a year of faultless behavior, suddenly it's all going bad. With no warning, my baby started to misfire, and idle roughly. Went through all the usual diagnostics, and conclusion was it that it was probably coil packs(standard Megane fault). These were replaced with no change. So it was off to the local specialist for a professional opinion. I was hoping that it may be as simple as dud spark plugs Nooo!!!! He says it's the "throttle body actuator", and that it will need replacing. At this point I had a heart attack, as the cost of a new one of these is around Au$2500 If there are any of you out there that can give me some good news, I might survive the week.......!
Cheers

[AlexB]

I doubt that the actuator can cause misfire. Flat spots yes, low or high idle yes, stalling yes, but not misfire. Have the OBD codes read from the ECU, then record and post here the engine parameters while idling or, better, when driving. ELM327 ($20 on Ebay) plus a laptop do the job, the OBD socket is in the central console. This will show which subsystem is playing up.

The throttle body often requires cleaning and lubricating, BTW. There can be air getting behind the choke, possibly through the petrol vapour re-breathing system. Start with OBD anyway.

[Markooo71]

Thanks for the advice Alex.......
I've spoken to the so called "specialist"........! There's 30 mins of my life I'll never get back!?
He's adamant that the problem is the throttle body, wouldn't even entertain the idea that it might be something else. He claims to have swapped parts with another vehicle, and that it fixed the problem. He's also telling me that injectors and plugs are also shot. I asked for fault codes, but was told there were none.....WTF????? My suspicion is he didn't even plug the car in... Approximate cost for parts and labour if he goes ahead......AU $6000!!

I'll be taking the path suggested, as soon as I can get OBD tools sorted, will post fault codes. In the meantime, will look at possible air leak

Cheers

[OwenBoy]

What is the age and mileage of the vehicle?

I would look at cleaning the throttle assembly, and check if you have any air leaks in your pipework, set of plugs wouldn't break the bank if they are fouled.

Fault codes and live data would be useful.

How can he determine you have faulty injector/s with no fault code's? EGT's?

How does the price more than double when adding labour?

[Markooo71]

Well, Madame 225 is 5 yrs old, with only 62000km(38000 miles) on the clock. She should be in her prime!
As far as "the specialist" is concerned, I think he's trying to pull a fast one......
No fault codes, 7 hours of diagnostics, and way over inflated parts prices;
Throttle body actuator $2500........... Available from Renault for about $800
Plugs $100 each........................... About $75 a set from the local auto store
Injectors $250 each....................... Flushed and cleaned for $100, full set
And his labour charge is off the planet, $80/hr, and he wants me to pay almost $600 for the work that he hasn't done. And then theres the coil connectors that he destroyed, and is telling me that they were like that when he got the car. I'll be taking this one to consumer affairs, me thinks.........
I'm in the process of sorting out some OBD tools.

Thanks for the advice OwenBoy......................

[Markooo71]

Been a looong time since I was in here last. Sometime life gets in the way.....!
Finally got things sorted with Madame Megane. Turns out it was clogged injectors from contaminated fuel!!!!!
Wish I had kept my reciept, coz as it turns out, I would have been able to claim the cost of repairs back from the fuel retailer. I've been advised by a lawyer friend to keep receipts for a month to make sure