engine cough

[bolder]

whilst accelerating or crusing sometimes not even every drive just one offs, the engine will slow like cough then be fine and run great as uasual, only lasts a split second but noticable esp wen youv got ur foot down , was thinking erg valve or tb, but never happens at idle and is v smooth at idle, and wen its cold out like 10 degrees or less it neva happens, so does that rule them out ?. no lights on dash,thanks

 

[pgarner]

sounds like its missing.
have you checked/ changed the obvious sparks and HT leads

 

[bolder]

they were changed 6000 miles ago, i was looking over anougher forum and it looks quite a common problem, aparantly its the precat but im nt sure, if it was sumink like that id expect itto happpen all the time n not be better in the cold

 

[lutonmatt]

only thing with it happening every now and then it is hard to find the fault alot of the times i say have to drive it till it gets worse as then it should be easyer to find
but i would rule out everything you said
and agree with pg likey to be on the ht side so plugs leads or coild as they are common to go

 

[HDi fun]

Does the Renault have plug top coils?

 

[lutonmatt]

ya if it does likey to be one of them they go all the time look at number 2 is my guess lol


i did that once to a bloke my dad works with had a v6 pug coupe i said would be number 5 coil not even seen the car was right lol

 

[bolder]

sorry my fault, i now own a 53plate astra 2.2 bertone coupe

 

[obi_waynne]

Is the engine showing any fault codes through the diagnostic port?

 

[bolder]

iv been told if the light on the dash isnt on which its not and neva even has flickerd, that it wont show an codes

 

[BAD63R]

Try doing the paperclip test on the diognostic computer port. Think iirc it's pins 3 and 5 you touch and even if the EML light has never come on or has not been noticed the, the ecu can still store any faults aslong as the ecu hasn't been reset. This would be my first port of call and its free so give it go and see where you are

But I have to agree with pgarner and lutonmatt, my Veccy GSI did this very same thing on the first set of pulse plugs I had fitted when remapped, fine when driving normally, floor it and it missed like bi-atch. Went back, fitted a different set of plugs and found out one was faulty and ran fine from then

But do check the fault codes with thepaperclip test first as it wont cost you anything and you may be suprised to find a code or 2 on there.

 

[lutonmatt]

i would not use the paper clips as its ok on the older vauxhalls as they use flash codes but the new ones dont and can do damage

but just cos the light has not come on does not meen that there is no code the fault has to happen 3 times for the light to come on and has to happen 3 times with in so many rounds of the ecu
worth a read out