I've cured my idle problem... Err, with the crankcase breather?!?!

[Conker]

I'm currently celebrating with a nice hot cup of tea, after having fixed my [continuing] idle issue...

...By removing the crankcase breather     


In short, the revs were bouncing from 500-1500 at idle. I pulled the crankcase breather out in preparation to do the "rubjonny tuning guide" (with the engine still on) and the idle just fell back to 1000rpm and stayed there.  F#$king result!

But.... WTF does that mean?  Perhaps fuel (or sum'fink) is being "breathed" out into airbox and then re-burnt causing different mixtures, or perhaps theres some kind of blockage? (1991 16v by the way)

Over to you dub brethren...

PS:   I'm this happy:  http://www.youtube.com/watch?v=DaJUEXxf8pY

[...joe]

not sure what you've been checking before this but i'd clean out the throttle body and associated pipe work and get a new crankcase breather and bung, then do rj's tuning guide as a start.

[Conker]

Believe me... I've done all the usual stuff first (electrics/dizzy etc, cleaned everything, done timing). I was at the stage of doing ISV control module, injector seals, fuel pressure etc.

The car is tuned fine, its just that when I reconnect the breather hose it screws up the idle. I've noticed that there are visible white-ish vapours coming out of the breather hose all the time.

I've been reading about PCV valves (positive control valve IIRC) on the crankcase breather that regulate how much gas is being sent through the breather for burning off  -  perhaps this is screwed up?  (if a 16v has one?)

[Mew]

Right, i'm off to check if that sorts my idle!

[Conker]

Been out for a drive tonight - fookin' loving it! Its like a different car.

I'm thinking my oil is contaminated with fuel, and so the vapour is affecting the fuel/air mixture.  This probably means my entire engine is bummed beyond all recognition, but I'll try an engine flush next week and see if that sorts it.

Excuse my gayness, but I actually blew someone away at the lights, I was that ecstatic. 

And no, not that kind of "blow" you pervs!   

[Mew]

So have you just left the hose disconnected for now?

[Conker]

Ahem, errr, its cable tied to an injector pipe. (to stop it falling into the alternator belt)

It'll prob sp$nk oil onto something,  but for the time being I couldn't give a sh$t.

 

[jammac]

i disconnected mine when i changed my breather bung and there was a white spunky looking gunge in the pipe to? what is it?

[Conker]

i disconnected mine when i changed my breather bung and there was a white spunky looking gunge in the pipe to? what is it?

Apparently thats quite normal as the oil vapour mixes with moisture in the pipe and turns to mayo. Moisture etc. is burnt off in the engine whereas the breather pipe does not get that hot, so moisture can linger. Give a clean out with WD40 every now and again I guess.

[Leon R]

What ...joe said, when i cleaned out every single vac pipe with brake cleaner and changed the airfilter the car was something else, always spun between 1st and 2nd gear when i gave it some. The oil from the crankcase breather pipe going into the airbox was thick full of it and i guess its from where previous owners overfill when topping the oil up.

You can remove the crankcase breather with 4 allen bolts:



and give that a soak and clean out as that too was filthy on mine.

incidently to get rid of fuel in oil, you should take it for a good long hard run. But the fuel getting in the oil could be more of a problem!