Slight hesitation and sluggishness 172

[alex-avfc]

Hi,

My 172,which has always felt very responsive and lively has got a bit sluggish seemingly in the last week or so.

I also notice it's a bit surgy or hesitant in the lower revs from cold, not that I ever take it past around 3.5k before it's warmed up anyway.

It's doing no better than about 36 mpg on my daily commute which is 32miles, mostly dual carriageway where I sit at 70.

It's had a new lambda sensor in the past according to invoices so I'd hope it's not that, would new spark plugs be a decent shout?

Cheers,
Al.

 

[The_Pirate]

Which lambda mate? Maybe swap them and see where that takes you?

Is it mis-firing at idle/start up?

 

[alex-avfc]

Ahh, do these have two? I wouldn't know which one mate just know its had one in the past from an old invoice.

It doesn't misfire as such just hesitates a little through the rev range, it goes away once warmed up but then seems a little sluggish, like the handbrakes partially on!!

Other thought is tdc sensor which did play up a few months back (car wouldn't start) which has been fine since I took out and cleaned, could this need changing?

 

[Cookson]

They all hesitate when cold.

I would chuck a set of plugs in, see how it feels then. When was it last serviced/oil changed? That can make a difference.

PS - Make sure you get the correct NGK plugs and use 5w 40 oil

 

[alex-avfc]

Last changed the oil less than 1500 miles ago using Fuchs 5w40 stuff from Opie. Always run it on super unleaded too.

Think you're right about the plugs though, I don't know when it would have last had some (if any) though it is on 112k.

Interesting to hear that they all hesitate from cold. I must say I hadn't noticed it before though.

Thanks btw!

 

[martynzs]

Mine also seems to be suffering slightly, even when warm. I put it down to the fact its quite a cammy engine, but maybe it does need plugs/lamda?

It feels slightly flat/hesitant at cruising/traffic speeds (40/45mph) but is fine when you push it a little.

Did you find a solution to this Alex?

 

[fraz101]

Agreed that they all are a bit hesistant when cold.....mine is too and always has been......

 

[Hixle]

When were the plugs last changed mate?