Misfire at idle

[oVerboost.]

Picked up a phase1 172 today, the car drives nicely however I have a misfire at idle. I know they idle lumpy as standard but the car does have a very slight misfire at the same time however when driving in any gear - no misfire. Could it be that when the engine was steam cleaned its got dampness in a plug or lead/coil pack?

Anything else I can check/clean/adjust?

Thanks.

 

[K-Tec Racing]

take the plugs leads out, make sure its all dry

while its out, check the plugs as well.

Andy
KTR Sport

 

[oVerboost.]

I took the plugs out and one was very black the rest looked ok but weren't brilliant so put some new ones in, car still idles a bit lumpy but I've been told that most 172 clios do that due to the cams used, but in general response is much improved as is smoothness so fingers crossed the problem might be sorted. The plugs I took out where denso ones, I've heard bad reports about these on other cars are they known to be bad on clios too?
Thanks.

 

[Da]

The Clio's don't seem to like any other plug than the OE NGK ones.

 

[oVerboost.]

I used a set of Bosch super 4 plugs which was all I could get but they seem to have made a big improvement may also change the leads too as it's got some beru ones fitted which I think are GSF leads.


Sent from my iPhone using Tapatalk

 

[the_prophet]

cool, glad its better sorry i couldnt help you on pm!

luckily ive got a set of plugs to fit to mine tommorrow (NGK's)......may be the answer!

 

[oVerboost.]

Fingers crossed for you, hopefully the plugs will sort your problem too. let me know if they do or not, also check all your vacuum hoses on the inlet/throttle body etc.

 

[the_prophet]

yeh gona give it a good check over tommorrow whilst the inlets coming off so see how it goes. if not then maybe injectors as someone mentioned to me before...although confused how it could only affect it at idle and not through the rev range.

 

[oVerboost.]

Yeah I dont think its your injectors, I did run a whole big bottle of redex injector cleaner with a full tank too which may have helped but who knows...lol

 

[the_prophet]

lol, see how i get on and i'l let you know

 

[Dunn]

thats just how the clios run lol im used to it after 5
i replaced alot of parts an it never made much of a difference
they do benefit from sum new ngk's though i must say
its just the cam set up which is why you dont get it through any of the rev range

 

[the_prophet]

no this is definatly a misfire on mine. it used to be lumpy but it "chugs" on idle and it was picked up when it was mapped a while back.

 

[oVerboost.]

So it is usual at very low revs/idle that the engine sounds like it is slightly misfiring? The new plugs seem to have made an improvement this morning but the cold start issue (seperate problem) is still there. Think that must be the idle control valve as the car just dies if you rev the engine and let it idle again, the needle comes down and then goes straight down - so not catching on idle. Any ideas?