182 misfire help!

[olly_mango]

My 182 developed a misfire, but only on the odd occasion when accelerating quite heavily. So I changed the spark plugs, leads, lambdas and coilpack (all the normal) trying to sort it and now its misfiring as soon as it starts up and smoking quite heavily, i've cheacked the plugs, leads and coilpack on my friends 172 and they all worked fine, so its not an issue with them.
Any more idea's on what to try? As i'm starting to think it may have dropped a valve so i'm going to get a compression tester.

Thanks Olly

 

[ForceIndia]

I had exactly the same, intermittent misfire, only under heavy load. Turned out to be the lambda.
If you've tried that already, and given it's smoking etc, I'd get it comp tested. Can't think of anything to try before that.

 

[ClioChloe.]

Compression test is what i was going to suggest

And get it on a diagnosic machine if you can, never know what it could revial

 

[olly_mango]

Waiting for a car to borrow of the rent's so i can go get a halfords cheap job and just test it and see it if shows any thing up.

 

[ClioChloe.]

Waiting for a car to borrow of the rent's so i can go get a halfords cheap job and just test it and see it if shows any thing up.

Hope it's nothing serious, good luck

 

[Da]

You could try the MAP sensor, might be completely unrealted but I was having misfiring and hesitation issues and it turned out to be the MAP.

Car was smoking too as it was running rich.

 

[ForceIndia]

I'd check it on an rstuner if possible. Mine didn't show any errors on a code reader, but had a stored error that the rstuner picked up.

 

[olly_mango]

I've got an obd code reader that doesn't pick up any faults on it, will have to see who's got an rs tuner near me.

Where abouts is the map sensor? any way of checking it other than borrowing or buying a new one?

Thanks

 

[Da]

It didn't show any faults on mine either, I think it's Renault only diagnostics.

There isn't really any way of testing it besides buying/borrowing one. I suppose you could unplug it with the engine running and see if the misfire gets worse/stays the same.

It is on the drivers side of the plenum, I'll get a pic hang on...

 

[Da]

The MAP sensor...

be careful if you try and remove it as this could happen...

The MAP sensor measures the vacuum inside the plenum and from that decides how open the throttle is. From that it works out the ignition timing and how much fuel to allow in (very simple terms).

 

[olly_mango]

Brilliant thanks, i'll go and try unplugging it now and see what difference it makes.

 

[olly_mango]

just unplugged it and it fired up as per normal, no misfire at all. So off to Renault to get a new one tomorrow! Thanks mate, you've just saved me a lot of time and money! Any idea how much they are?

 

[Da]

Excellent news! :approve:

Brand new they're £70~ from Renault, but PM joshydee on here (ClioSpares.co.uk) as he does them for £20~ with 3 months warranty.

 

[olly_mango]

Thanks for your help, will do it now.

 

[ripp]

It didn't show any faults on mine either, I think it's Renault only diagnostics.

There isn't really any way of testing it besides buying/borrowing one. I suppose you could unplug it with the engine running and see if the misfire gets worse/stays the same.

It is on the drivers side of the plenum, I'll get a pic hang on...

I unplugged mine today with the engine running and it stopped. does this mean anything?

beside this, I have a lumpy idle since I have the car, but got used to it since otherwise the car is fine. could replacing this sensor solve this idle issue?