182 55 plate misfire

[ital]

Hi all,

Currently i have a misfire on a 55 plate 182. i have done some research on here, and online which suggests usual things, coilpack, plugs, leads. Ive swapped all of those with parts on a friends car that i know work. Misfire still there and getting worse. Then research suggests injectors. So took rail off and checked they were all firing, they were as far as i could see. Compression was then checked, and was ok. When you pop one of the leads off the injector it diesnt affect engine which would suggest it was that injector, but when you plug the lead back in it picks up ever so slightly. But as far as i can see that injector is firing.

I have one plug that keeps going black with carbon. I changed the plugs last wkend for brand new ngk.

Getting to the end of my list ofvthings to check now. All i have left to check is o2 sensors pre cat. And the cat itself. Any ideas how to test the cat itself without buying another? And does anyone have any other ideas what it could be?

Many thanks.

 

[ital]

This misfire is on my rb track car not the bg 182 ff im selling just in case anyone thought i was trying to sell a shed!

 

[Pink-182]

The cat would normally smell of sulphur ( eggy) if it's knackered but not always. I just had a similar problem on my 182 cup which was a spark plug and lambda sensor precat. If you can get the car jacked up nice and high it is relatively easy to change and is about 60 quid. In the end I went to my local garage that plugged in diagnostics machine for free. Renault wanted 75 quid for what was a 20 second job!

 

[ital]

Don't suppose you know if the diagnostic machine said it was the lambda precat? I've had mine plugged in on the ethos snap-on diagnostics and it just says destructive misfire four times. not massively helpful to be honest! I changed all the spark plugs last wkend so def not that.

 

[Pink-182]

Switch the post cat ( really easy to get at) with the pre cat. I was told the pre cat goes most commonly and will naturally be dirtier to look at. If the car then drives better it will be this. I don't know which machine the bloke used on mine but after I had changed the lambda sensor it said there was a misfire in cylinder 2 . So was easy to locate. Out of interest are any error codes showing when you hold in the trip computer button and turn the ignition on? This sometimes gives more clues as to what might be wrong.

 

[Pink-182]

Last thing I can think of is if there is any air escaping. You can normally here it if it is though. Check gasket condition.

 

[lemonnobby]

you can with it running disconnect the injectors one by one and see what happens.

 

[ital]

What did the misfire on cylinder two end up being if that showed up after you changed the lambda? Not tried holding the trip and turning ignition, didn't know that showed error codes? Yea I have checked briefly for any vacuum leaks, but nothing obvious.

Have disconnected all injectors and fired them. They all seem to be fine. But not tried removing one at a time so will give it a try.

Cheers

 

[Raymond_11]

I had the same problem on my 172 a while back and it was the tdc sensor

 

[Coops Mk1]

the pot with the black plug, swap that injector, its fautly, it may be firing but not correctly

 

[ital]

Ok will give it a go 2mo. Cheers