Revs going from 2500 to 5000 on start up

[cowboy573]

Got in my FN2 yesterday, to go do shopping and when i started it, it struggled to tick over so i pressed the accelarator to give it a help, the revs shot up to 5000 the dropped to 2500 then back up again then dropped, and it just kept doing it, even through my foot was steedy on the pedal. So i charged the battery up over night just to make sure she ticks over okay for this morning, 'We'll this morning it started no problem, (fully charged battery, so it should) but it still reved really erratically. I wouldnt normally rev as high as 5000 on start up, but this has got me concerned, The Honda warrenty runs out in March is this something i should worry about getting looked at??

 

[Loxy]

Has it been stood a while?

 

[cowboy573]

Parked up friday started up Sunday. and again today

 

[Loxy]

Maybe not then. I was thinking moisture in the ICV. Mine was like that when it had been stood before I bought it.

Check it for any splits in the intake hose where air could get in post MAF sensor, check the hose is sealed to the TB, check no obvious leaks on the joins of TB to inlet manifold and inlet manifold to the block.

If that's all OK do a bit of an Italian tune up and see what it is like in the morning. That is assuming everything else is alright and you aren't omitting an EML or something. :lol:

 

[cowboy573]

I should point out, that it idel's fine if i dont rev it. also once it's warmed up its okay. its just starting it after its sat for a few hours it does it.

 

[cowboy573]

On further investigation, i think my mind was playing a few tricks. The rev's dont go down as far as 2500, what seems to be happening is it hit's 5000 and it's like it's hitting the limit and it's bouncing of it, but put the car in gear and drive it and it'll go past 5000, even if she's warm if you put it out of gear the limit is 5000rmp. Is this maybe a safety feature built in? Being in mind i wouldn't have noticed it if it wasn't sluggish to start, as when do you normally sit revving it to 5000rpm?

 

[Loxy]

Aye that's perfectly normal!

It has a lower rev limit when you are stationary to stop you going into VTEC when there is no load on the engine.

I remember finding that out on my EP3 and thinking it was broken until the penny dropped! :lol:

 

[cowboy573]

Strange how long it can take you to notice things. Also, all the way home from work today i kept "thinking" it was playing up, But i bet it wasnt. Now i know it's a normal thing ill just get back to enjoying her.
Thanks Loxy