323i Breathers and Coolant Hoses

[e21Keith]

I'm hoping to get the engine running within the next week or so. I'm a bit confused with one of the coolant hoses and the breather system as the parts I'm using are from 2 different cars which had different setups (differences between 1980 and 1981 cars).

The first question relates to the cooling and I think I know the answer. The warmup regulator from the 1980 car does not take water from the cooling system it just warms up as the block heats. I believe the bypass hose that exits the block at the back on the right hand side (under the heater valve) should run to the top of the thermostat, is that correct?

I seem to have 2 sets of breather and vacuum hoses. The 1981 car had the air slide valve and this is probably what I'm going to use. The 1980 car didn't have the air slide valve, instead it had an aluminium block, a sort of junction box with no electrical connection. I have a big box of bits but I don't know what's from which car or where it all goes. I can't work out from the ETK which diagram I should follow?

Does anyone have a diagram or description of what goes where?

[Jeroen]

There are two versions of the aux air valve that dictate how to hook things up. An electrical version on the earlier models but similar to the one used on L-Jet cars, so connections electrical connector and two air hoses. The later models have a valve that is operated by coolant temperature. The two hoses closest to the engine are the actual air valve, the other two are a coolant bypass that regulates the valve through a wax element.

For starters I have a pic of the disassembled setup for the later version. Mind you the even later models (I believe from late 1981 on) have an even different setup but that's pretty rare, I believe not even all the Edition S's have that setup.

[e21Keith]

Jeroen, many thanks for your explanation.

I think I'm going to use the earlier setup with the electrical connection as it seems to be a little simpler and I have all the parts. This means I will have to order some new hoses as they are cracked. Do you know how I check the electrical connection?

Think I've sorted the coolant, there is no connection to either the throttle body or the warm up regulator so the bypass goes straight from the back of the block to the thermostat housing.

[Jeroen]

Believe its just plain 12v so should be easy to measure.

[e21Keith]

Well I think I've understood so far and I have all of that assembled this afternoon. However now I have 2 other questions?

1. Vacuum hose for the servo, again there seem to be multiple options and I have three sets of pipes. The most simple seems to be a single pipe with a non-return valve that goes direct from the inlet manifold to the servo, really I'd like to use this set-up.

2. The guibo that goes from the AFM to the throttle body has two connections on it. There's one facing the bulkhead which goes to the breather but there is another facing the radiator and I don't know where it should go, looking at pictures on the internet some seem to have a connection but some don't, but this would leave an unplugged opening on the guibo, do I have the wrong guibo, should there be something to blank it off or have I made a mistake with my plumbing?

[e21Keith]

Think I've answered the question on the bellows, looks like there should be a blanking plug in the hole that faces the front of the car?

[Jeroen]

1. over the years BMW has done a lot of fiddling with the vacuum hose layout to optimize things so yes, there are multiple setups possible. On the photo above the braided hose is the one that runs towards the brake booster and that hose always has an one way valve.

2. from the factory, the hole facing the front of the car is blanked out indeed, but perhaps that is being used on cars with an EGR or used with LPG.

[e21Keith]

Many thanks Jeroen, it looks like I'm missing whatever blanks the hole, I've ordered a new bellows now anyway.

I need only fit the metering unit now and the engine will be ready to start for the first time in I don't know how many years. I'm getting quite excited!

[Jeroen]

Fingers crossed! Keep us posted! And with K-Jet, be prepared it won't start right away.

[e21Keith]

I'm hoping for the best, I will have one friend standing by with a camera and another with a fire extinguisher....

[shadyracer01]

Keith, ive got 2 323i engines with same breather set ups that suit the coolant heated add.air slide, both intake bellows have got the opening facing radiator with nothing plugged in, although there is a hole in the stem its not all the way to the inside of bellow, i tried blowing through, its sealed unless required for system as Jeroen suggested, extra egr or lpg. So maybe you dont need new bellow and are ready to try starting it up. Oh, what did you do regards replacement cold start/ wur pipes etc?

Ive had a lot of components apart inspected and cleaned eg wur/ fuel metering barrel plunger/ ign distributor in my quest to get my 323 resto finished and starting / running smoothly. Got 2 recommendations for you, new diode relay and strip down and clean of wur. Diode relay caused host of starting and elec supply issues to time/temp switch etc, Wur fix got it running smoothly but I was lucky that the diaphragm was mint and o ring not flattened, reckon a blockage in
a port was my issue, ahem, caused by me blowing the inlet filter with blowgun from outside in, shame on me hehe..because i didnt want to risk breaking the mounting bolts to engine block. i didnt break them after all. Thought it might be of help to you sharing my experiences, so good luck and happy to help if required

[Jeroen]

Agree, a good cleanup of the WUR membrane might do miracles. Modern day fuels tend to become gooey after a long period of standstill and that is not only affecting the fuel dizzy, fuel injectors and the fuel pump, but also the WUR indeed. The in- and out ports at the WUR are connected through a membrane and when it get clogged, the WUR looses its function, usually causing cold start issues.

[e21Keith]

Thanks for all the advice.

I'm using parts from 2 donor cars, the first ran about 5 years ago, the second, the engine was in bits when I bought the car 4 years ago, so who knows, but I've used the parts from the first car!

I've used what I think is the earlier breather with the electrical connection and the vacuum hose for the servo goes straight to the inlet manifold. One of my bellows had a hole on it for another pipe, the other as you say was blocked so I used that one.

The fuel tanks are as new, cleaned inside and powder coated outside. New fuel pump and filter, all new fuel lines. The accumulator, metering unit, WUR, cold tart injector and fuel injectors are all original, but have been sympathetically cleaned with WD40 and cleaned out or soaked in fresh petrol, just hoping luck is on my side and that it will run. Even if there are problems with the cold star system it should run or at least fire, then I can start investigating issues. I've taken this approach as I just didn't want to renew and refurbish everything, it was running 5 years ago so I'm hoping for an element of luck.

The new air filter arrived today, so it's ready to start. I have a very good friend who was a master technician for Ford in the 80/90's and so he has a very good understanding of k-jet, he's available on Saturday so that's when I will turn the key!

One last job before then is to align the exhaust system, I bought parts online as and when they became available with the result that no two parts are from the same manufacturer, it all fits but doesn't sit right at the moment.