running out of ideas

[hillclimb_clio]

OK just an update on where the 172 Cup has got to with its little mis-fire issue: Changed plugs (NGK OE), changed HT leads (Magnecor 8.5mm), cleaned throttle body, cleaned TDC sensor, checked emissions @ MOT station (oxygen 1.5 rather than 0.5 apparently) & re-set parameters according to mechanic - not sure what he meant by that to be honest. Apart from the coil pack what else is there to try?! This is starting to get expensive & just a bit annoying now as it STILL mis-fires at about 2k revs & clears itself by about 3k revs. Car is standard except for a Piper Cross Induction Kit (the cause of the high oxygen reading?). I know the exhaust has seen better days but surely that couldn't be the cause could it? Any help and/or suggestions gratefully received! :S

 

[Jay Payne]

Is the exhaust blowing?

Done a compression test?

Vaccum test on idle?

 

[hillclimb_clio]

meant to ask the garage to do a compression test when they were doing the HT leads but as the 1st set were faulty it all got a bit hot & bothered & I forgot. Don't think the exhaust is blowing, just a bit rattly. Not even considered a vaccum test on idle - how would you do that?

 

[barnesautos]

injectors , can cause misfiring. come and go thru rev range get em checked.

A trick/the nuts diagnostic recorder can monitor engine behavior when its misfiring and a decent tech can see what cylinder was missing hopefully.

swap over injectors and see if fault move to another cylinder and recheck

hope this helps in anyway

 

[hillclimb_clio]

@ barnesautos - cheers, have spoken to a local Renault guy & he has also suggested an injector so its booked in on wednesday to find out!