172 acceleration problem

[cal]

Sorry to start new thread but struggling to find this problem on forums.

I have an '02 172, problem ive got is that engine is not moving through revs smoothly when accelerating. It will rev smoothly until about 4-5k then the revs seem to go sticky, holding and releasing the rest of the way to the limiter (around 7k) Makes acceleration jumpy.



If anyone has any suggestion what this may be and/or how to fix would be much appreciated, cheers

 

[cal]

Any ideas?

 

[Shervi]

Spark plugs come to mind...?? When was that changed last?


How well does it idle? There could also be a sticky throttle body ( this could be the case, but it does seem a little unlikely)

The other side to it with be the engine management system. If the engine managment system is being fed the wrong info, then it would cause it to behave irregularly and different rev ranges. With this in mind it could be the lambda sensor, or the MAF sensor. The MAF sensor measure the amount of air going into the engine and adjusts the fuel input to match it, and the lambda sensor is on the exhaust. Now I am not sure if this car has a MAF sensor, but I know it has a lambda sensor.

Good luck!

 

[cal]

Cheers for response

not sure plugs have ever been changed to be honest! due 72k service so though they'l defo be gettin changed. Will this make big difference, as they prob are the originals?

Idles bit lumpy but seems thats quite a common trait for this particular engine, settles at around 700/1k. cleaned throttle body recently so hopefully that shouldn't be sticking.

Are those lambda and MAF sensors difficult/expensive to change?

 

[Shervi]

Your forgot to put in the mileage of your car

But yeah, it looks like ignition problems. My car idles pretty well. It isn't that lumpy. But I have had previous experience with a car ( previous skyline) that had the spark plugs go, which caused to it rev up irregularly through the rev range. And all it needed was new plugs. Doesn't matter if it's originals, but if it goes it goes

All it takes is for one to perform poorly, to let the rest of the plugs down. If the car is close to a service, then get it service ( with the new spark plugs as well ) and then see how it rides?

What do ya say?

 

[JT182]

As above really, but I had a similar sounding problem on my old 182 Trophy. It would rev normally to the limiter, but then as the drive went on it would deteriorate and only rev to around 5000rpm. It used to drive me mad when it happened. Turns out the problem was the fuel pump, and once that was replaced for a new one all was well.

Just something to think about.

 

[cal]

nice one cheers for both your advice. il be gettin it serviced asap, will see how things are after that.

will post on here once problem is solved hopefully!

 

[cal]

since last post had plugs changed, 2 of the the old plugs were f**ked! car is pulling nice and smooth now all way to limiter