URGENT help! 4500 RPM idle

[C2kev]

first of all im driving a 2004 flame red 172. I just tried changing the spark plugs, stripped it all down only to realise i don't have a socket that fits the plugs. so i put it all back together again, start the engine and the rev's shoot upto 4.5K rpm. Wtf have i done?

 

[77richard77]

Have you left one of the small pipes out of the inlet maifold?

 

[C2kev]

not that i know of, I'll go check

 

[mx1_champ]

sounds like a vac leak check all small pipes are connected to the plenum

another good way to test is

spay wd40 or equivelent round the inlet ( as a mist say 15cm away not directly on ) and if there is a leak the engine will suck the oil in and make it bog slightly

 

[C2kev]

what does this pipe do? it was sqaushed flat, unsquashed (is that a word?) it now and all is sorted cheers lads

 

[Will.]

That has something to do with pressure IIRC. When i fitted my induction kit i forgot to put mine back and it reved right up.

 

[mx1_champ]

might be the vac line for the brake servo... yoru brakes any good at the min ?

 

[Tobs]

its a vac line for the acoustic valve that sits below the passenger headlight, not really needed as it does feck all.

just make sure u havnt split it

 

[DrR]

There is also the small pipe on the 90 degree induction pipe