engine and drivetrain Vacuum Leak??

[jgerock]

An early Inka tii - looks like 2760598. Congrats! I know of another one in the Athens, GA area. Check the breather hose that runs from the valve cover to the air cleaner. About 1/2 way, there should be a plastic fitting and smaller diameter vacuum hose that connects the breather hose to the throttle body. Most I have seen are in poor condition or even missing.

[tomphot]

Thanks - it's 2760698 born on 1/18/72.

That hose is there, I need to hit it with carb cleaner to see how good it is.

[Conserv]

That nipple has a tube attached to it that goes to a Vacuum gauge that the PO installed. I was hoping it shouldn't be there and that the tube should be attached someplace else, thus creating a leak that would be easily fixed.

Tom,

You obviously need to find a leak from the throttle body to the head. So, right, that small nipple on the airbox isn't currently, and wasn't historically, connected to that critical area. But the small hose Jim G. mentions is.

I notice that the vacuum line for the brake booster still has a small piece of cloth-braided line from the aluminum intake plenum (accumulator) to the check valve in the line. This was very high quality hose but if it's 43, or even 33 years old -- heck, even 23 years old -- I'd probably just replace it: the rubber under the cloth deteriorates...eventually.

Good luck,

Steve

Edited June 13, 2015 by Conserv

[tomphot]

I was thinking that little nipple is a useless spot for a vacuum gauge - am I correct?

[Conserv]

I was thinking that little nipple is a useless spot for a vacuum gauge - am I correct?

I certainly had the same thought, Tom! It wouldn't be hard to convince me that that gauge never worked!

Steve

[Henning]

If you may think about adjusting your valve clearance, Tom- please do to all of us the favour to check the cover's date. It seems to be one of these E21-series style with the inclined threaded block next to the breather hose, not your original one. And additionally, there are these short sinews above the crossover between head and upper timing cover. I thought they appeared with late E21 series, but those ones didn't have the tii-style intake manifold- or did US 318i/320i have, including the drawn-in hose connector??

 

 

And try to get your original cover back. The needless block is disturbing.

 

Hen

 

[tomphot]

Thanks Hen

Yes, I know that's not the correct cover. The PO had a new engine built by BMW in 1996 through a friend who owned a dealership, perhaps they put the cover on at that point.

I still need to make another trip to the POs garage - I'm getting the original engine, another steering box, complete KFish setup, throttle body and "lots of other stuff".

I'll take cover from the engine and put it on.

[tomphot]

I just performed a smoke test using Fuente

Smoke was coming out of the top of the warmup regulator by the screws. If the car is running, is that area sealed off? If not, could this be causing my issue?

Edited June 14, 2015 by tomphot

[PaulTWinterton]

Definitely suspect.  There is an air hose connected behind the WUR which routes to the underside of the air intake "log". 

 

Use cloth-covered visegrips to pinch the hose behind the WUR.  Engine will change note, either higher or lower rpms, if there is an air/vacuum problem.

 

The WUR introduces more air into the intake while in operation.  Once the WUR is at the warm condition, no extra air should be introduced into the intake.

[tomphot]

Thanks Paul

I just watched the WUR during warmup, the rod only extended about 6mm

[PaulTWinterton]

Still try clamping that hose.  It will confirm if the WUR is suspect.

 

Sometimes with age the piston will be misaligned.  It should be flush when cold and 10mm when hot.  There is an allen key adjustment to reset the piston from below flush to flush.  Then with a boiling water test on a stove, it should rise to 10mm again.  It means removing the WUR to work on it, unfortunately.

 

The purpose of the WUR, besides introducing more air into the system is to regulate the fuel via the tophat and KFish enrichment lever.  When the piston is fully extended the tophat and the lever to the KFish should be dis-engaged from each other.  If it's disengaged it is doing it's job.  Read up on the adjustment of the tophat and how it effects the enrichment lever.  There is a "stop" that has to be set at 2.6mm (IIRC).  Read up. 

[tomphot]

Thanks for your patience - this is my first BMW and first time dealing with KFish. I bought the car 2 weeks ago and had no idea what I was looking at under the hood.

It looks like that unit would be interesting to change out considering where it is.

When I bought the car, the PO gave me a lot of extra parts in boxes. Included was a whole fuel injection set - KFish to throttle body. It's been nice to be able to hold them in my hand while reading. I did the boiling water test on the extra WUR and it went out to 10mm Though it's not completely flush when cold. I need to get some longer pliers to reach that tube you suggested so I haven't done that test yet.

I will continue to read up.

[PaulTWinterton]

With your spare, set the allen key adjustment so the piston is flat when cold.  Measure when hot.

 

Approximately 8-10 mm rise from flush may be enough.  When the piston is flush (cold) you set the 2.6mm enrichment lever adjustment per the Kfish instructions.  When the piston rises the tophat disengages the linkage and is not longer part of the system.  I've found that there is 1 mm tophat clearance from linkage when hot, so the 10mm doesn't have to be exact, I THINK.

 

If you are getting an air leak at running temperature with the piston elevate fully, the WUR may need a rebuild.   You'll know once you clamp that hose.

Edited June 14, 2015 by PaulTWinterton

[Conserv]

Who is rebuilding warm-up regulators nowadays, other than the heavy-duty pump rebuilders, e.g., Hans, Redszus? Rob (2002haus.com) was getting WURs rebuilt on a standalone basis, but is not currently. On the other hand, Rob might have a bunch of good used spares.

Regards,

Steve

Edited June 15, 2015 by Conserv

[tomphot]

Hey Steve - that was post number 3,000!!

Back on topic, would love to know WUR rebuilders just in case. I have 2:)