Sticking revs + slow dropping revs

[Barron]

Noticed recently on my 172 whenever i change gear from 2nd to 3rd gear the cars revs dont really drop. Its hard to explain but it sounds like its riding the clutch when changing quickly even when your foot is totally off the gas.

It only doesnt do this if you slow down your gear changes to a snails pace.

My brothers 182 and our track car doesnt do this so its not my driving before you say it lol :rasp: + i know these cars dont like to be rushed changing gears.

any ideas? vacum pipe is checked, and cleaned throttle body

thanks
carl

 

[Barron]

also to add, sometimes the car randomly sticks at say 2000rpm and only drops when dipping the clutch and reving the engine.

 

[Barron]

anyone?

 

[sammyhale22]

Yeh i know what u r on about. I think its just how these cars are sometimes. I reckon its just a combo of things, the fly by wire throttle being one that probably causes weird revs!
Although slow falling revs are not a concern, bigger displacement engines do have slower falling revs in general. Even the big supercars like Ferrari's, Porsche, Lamborghini have gradual falling revs rather than just dropping quickly. It does give you more time to change gear though in the higher revs, think about that lol

 

[Andyman]

Sounds like you have a sticking TB. Not sure how the leccy ph2's one (take it thats what you have going by the pic?) work so have a wee search

Other than that you could be sucking in air from a worn gasket.

 

[Ads_172]

Throttle cable matey, quite a common thing on the ph1's.

 

[Russ_16v]

agreed,mine did it, new cable fixed it

 

[Jay Payne]

hes talking about his phase 2 i think.


Check for airleaks and clean out the throttle body Harry

 

[Russ_16v]

my bad sorry dude, yeah i would say an air leak

 

[Cooksport]

weird thing but its happened before, make sure that the bolts are not over tightened on the engine cover. i know someone who put the bolts in the holes without the cover on and nipped them up, pushed the inlet manifold away from the head, and air was getting in, could be it, just a guess!!!

 

[Ads_172]

Ah right, ph2 - the avatar kind of gives that away! In that case... not sure.

 

[Riley!]

could be a few things. Electronic throttle pedal may be knackered, idle control valve

 

[Schweppy]

Sorted this now?

 

[Barron]

Sorted this now?

nope :S havent had alot of time to investigate it really

 

[Schweppy]

Oh i'm getting it too but also getting it cut out on idle.

 

[J-Key]

Take the air inlet hose off the throttle body and have a look inside.. if it looks dirty ie. black oil inside clean it out with carb cleaner... but make sure you spray plently of lubrication in there (ideally sylicone lubricant or a dry lubrication) after you clean it out

The car will run so much nicer and you will gte better throttle response and if its like mine better performance...

I had this problem with my PH1 and it sorted it... however be very generous with the lubircation because the cleaning product will dry out the components inside making it very dry and sticky

Give the spring on the side of the TB a nice lube aswell

 

[Andyman]

^^Its a ph2 not a ph1 172 Totally different ball game