Lizard928

This is mainly for Big Dave, but I figured I would post them here so that everyone can see this.

They are next to a TempII sensor for size comparison



this slides into the rear and more central vacuum steel hose connector at the base of the oil filler neck on 85/86 32V engines.



The hole on the bottom is to allow air out of the crankcase, there is a small plastic valve which sits inside the main body,



in this end when you look you can see the spring which holds the valve closed so nothing can go back into the crankcase.

This is the ONLY one of these little buggers that I have seen while working on these engines.
as far as I can tell though it causes pretty much no difference.

HTH

Big Dave

Thanks for the pics! Gotta wonder why Porsche used it if it doesn't make a difference. I'm still running rough, so I'm hoping this will help a bit.

Lizard928

when you say runs abit rough what do you mean? pulses abit at idle? or runs rough throughout the whole rpm range?

Big Dave

When cold, the rpms will bounce up and down between normal and near-stalling if I leave the car in gear while the car is stopped. The symptoms are much less when the car is warm, and sometimes gone completely.

I've been told it could be (a) MAF, (b) idle position switch, (c) idle stablizer, or (d) temp II sensor. Replacing all of these without figuring out which one is necessary could get pricey, and possibly totally wrong anyway. There's also a slight hesitation when I accelerate from a stop.

Lizard928

A few things that you could check.

disable to idle valve with the 3 pin plug in the front. And see if it still does it.
Did you adjust the idle with this bypassed too? I believe that you knew to do this though.

The idle switch I dont think will give you must of a difference, though if you want one for trial purposes I will throw one of those in with this and get it off tomorrow.

Due to the listed hesitation off idle/accell, and the idle hunting, these BOTH point to the AFR being too lean at idle/all rpms,
if it is slightly lean it will jerk abit off idle and at any point when you first put your foot down.
The car will fall and rise in RPMs as the car overly richens the mix to try to keep it running.
The idle valve being inop may do this when cold, but when warm/hot it should not do this, but the fact that it does do it sometimes I would lean more towards the MAF being out.
Did you adjust the MAF after rebuilding your engine? as the amount of vacuum could have changed slightly. If you havent tried this yet then do this first.

HTH.

linderpat

My symptons exactly. I know that a vacum hose that leads under the intake is off, because I remember when it came off, and I couldn't put it back on - after that, your symptoms. The late Scott Mohr thought that was the problem too when he looked at it (he showed me where the hose was supposed to reconnect - again, can't get to it without removing intake tubes). When I do my intake refresh this winter, I expect to see the problem corrected. I will get Roger's refresh kit, and replace all of the things under there. Hopefully that'll do it.

Lizard928

Linderpat,
I just went about this today (pulling off all the vacuum/breather lines) and you can get EVERYTHING out from the V without removing the intake pipes which are sealed to the heads.

This means you should be able to if you take the time to hook that hose back up.

linderpat

If I pull off the side wings, I might be able to get in there. Not much room tho. The problem doesn't bother me enuff to partially tear it down - I'm just going to wait and do it all at once, especially since the main part of the driving season is over for me now anyway...

linderpat

bump this topic - just finished my r&r intake, and didn't see this part in my oil filler neck hose. What is the upshot of not having it? I've got an 86. It wasn't in the old line, and I don't think it's in the new line either...

Shane

I have four '86s and have yet to see a valve like that either, so you are not alone Ed.

Mrmerlin

that little thing looks like an inline PCV valve

PorKen

This is where the valve lives, BTW. On both my '86s, the other pipe was crimped, so the valve could not be missplaced.

linderpat

I know I don't have it...just put on my powdre coated oil filler neck and there was nothing in either pipe...

PorKen

If the idle switch or connection is bad, the ignition advance at idle will be around 20°, versus the normal 10° when warm (13° cold, 15° really cold). This will make the idle correction 'dramatic', and it will 'miss' occasionally.

backnblack

Dave give me a call I have a new temp II sensor you can borrow and a timing light to check what Ken it talking about.
Matt