engine and drivetrain Solex 32/36 To Weber Dgas 38 Installation

[oldskoolvws]

Hi all,

 

Need some help, 1974 Base (04/74). Got the intake off the motor (what a pain) and am in the process of cleaning things up. All of the emissions stuff (magnetic solenoids, EGR, etc) disconnected by P.O. so removing that as well to clean up the bay. Changing out to Cannon manifold with 38/38, electric choke.

 

So question is, what is the standard practice for this conversion for the sensors and wires in relation to choke operation? I've searched and have not found anything related to it. I have not actually looked into anything in the service manual as of yet though. So far I have this:

 

HARNESS FROM ABOVE BRAKE BOOSTER TO MANIFOLD: (closest to firewall, going out)

 

black / red (SW RT) = Starter Solenoid

brown / black (BR SW) = Coolant Sensor bottom of intake manifold

green / white (GN WS) = Unsure. Pic below for reference, anyone know what it is?

green / blue (GN BL) = Choke

brown / black (BR SW) (2x) = Air Temperature

green / white (GR WS) = Idle Cut Off Solenoid

 

The biggest questions I have is will the choke still work? I've sourced the following and will be installing soon or do I just leave disconnected:

 

- Bypass neck with dual ports - relocate coolant sensor from below the manifold to right next to the one shown in the pic (upper left).

- Thinking of relocating the air sensor to the starter bracket (hole that bolted to manifold, drill and retap, left side of starter in pic).

- 10x1.5 plug for block, passage from carb to block (mid right in pic).

- What is switch in picture on carb? Not sure how to resolve.

- Waiting for manifold off ebay that has lower cover to add to Cannon manifold.

- Going to source Tii distributor to eliminate vacuum.

 

Am I on the right track or lost as hell?

 

Thanks.

 

Pat

 

http://www.bmw2002faq.com/_/technical-articles/engine-and-drivetrain/weber-downdraft-carburetor-installation-guide-r35

 

 

 

Edited May 26, 2014 by oldskoolvws

[oldskoolvws]

Also thinking about converting to manual choke and just run direct but prefer not too as the wife drives it more than I. She's more of turn on key and drive.

[GreenSwede]

I run a manual choke, so I don't have the foggiest about the electrics..

 

But, from what I've read you should stay with vacuum as long as you're carburatted. Carbs like advance. Never tried a tii on mine, though. I have a, what are the sought after ones.. 002? dizzy laying around but my 38 seems happy with vacuum.

[73touring]

As Green Swede said.

[Mark92131]

I've done this conversion a couple of times, so hopefully I can shed some light.

 

The electric choke on the Weber 38/38 is looking for a 12V switched source, so it stays on while the key is on.  You can use the feed off the emissions harness or another 12V switched source if you are removing the emissions harness.

 

My cannon manifold actually had a water jacket below the carb to help warm-up.  Water would run from the water pump, through the manifold and out to the heater.  If you don't have this feature, you will need to run a bypass pipe (320i part) to connect the water pump to the heater, (see picture).

 

I can't comment on the air sensor, because I didn't see it in the photo, and I don't have one on my car.  What exactly is it sensing, and what does it do with the information?

 

The connector on your original carb is most likely the idle jet cutoff solenoid.  This is also a switched 12V source like the choke and prevents the car from running on after the key is off.  Your 38/38 may not have this solenoid switch, so just tape the power source connector so it doesn't ground or remove the whole emissions harness.

 

You will need a new throttle linkage for the 38/38 over the 36/32, because the 38/38 turns in the opposite direction.  Order one from Ireland Engineering.

 

The 38/38 may not be jetted correctly for your car, if you haven't already done so, you can get a Weber jetting kit off of eBay.

 

I hope this is helpful, good luck.

 

Mark92131

 

[FunkyLaneO]

If you are desmogging your car (and since you are going to a 38/38 DGES I will assume you are) all of the wires sheathed in tan vinyl can be removed as a single unit, you can take the resistor wire out of the bundle and run that to the coil and run a new wire from a switched source to your choke.  all of the air sensors that plug into that bundle are part of your smog emissions system and are no longer needed, just remove them and toss them into C.D.'s neighbors pool with all the vacuum switches, relays, etc..

 

It looks from the picture that your EGR hose was cut, you will want to cap that off as well, you can do that with a brass cap from Home Depot right on the exhaust manifold or weld it shut.

 

Also, if your car has the original distributor, then it is a vacuum retard unit so for the meantime you will want to not hook up the vacuum to it (or else it will run like crap), that dizzy does have a bunch of mechanical advance and while not optimal it does run pretty well without the vacuum.  I actually thought it ran a little better than with the TII dizzy on my car (though a true vacuum advance from an earlier car is really the best way to go in my opinion).

Edited May 27, 2014 by FunkyLaneO

[oldskoolvws]

I've done this conversion a couple of times, so hopefully I can shed some light.

 

The electric choke on the Weber 38/38 is looking for a 12V switched source, so it stays on while the key is on.  You can use the feed off the emissions harness or another 12V switched source if you are removing the emissions harness.

 

My cannon manifold actually had a water jacket below the carb to help warm-up.  Water would run from the water pump, through the manifold and out to the heater.  If you don't have this feature, you will need to run a bypass pipe (320i part) to connect the water pump to the heater, (see picture).

 

I can't comment on the air sensor, because I didn't see it in the photo, and I don't have one on my car.  What exactly is it sensing, and what does it do with the information?

 

The connector on your original carb is most likely the idle jet cutoff solenoid.  This is also a switched 12V source like the choke and prevents the car from running on after the key is off.  Your 38/38 may not have this solenoid switch, so just tape the power source connector so it doesn't ground or remove the whole emissions harness.

 

You will need a new throttle linkage for the 38/38 over the 36/32, because the 38/38 turns in the opposite direction.  Order one from Ireland Engineering.

 

The 38/38 may not be jetted correctly for your car, if you haven't already done so, you can get a Weber jetting kit off of eBay.

 

I hope this is helpful, good luck.

 

Mark92131

I have a new idle solenoid valve on order for the 38/38 to prevent dieseling. That's not it in my picture. I still can't figure out what that is but I haven't really looked either.

 

The cannon manifold has provisions for attaching the earlier 2002 bottom plate of a manifold and running the coolant through it. I'm thinking about doing the bypass conversion because as far as I can tell, the coolant in the manifold is an emissions thing.

 

I'll get pictures of the air sensor. Very weird, but I have a theory.

 

If you are desmogging your car (and since you are going to a 38/38 DGES I will assume you are) all of the wires sheathed in tan vinyl can be removed as a single unit, you can take the resistor wire out of the bundle and run that to the coil and run a new wire from a switched source to your choke.  all of the air sensors that plug into that bundle are part of your smog emissions system and are no longer needed, just remove them and toss them into C.D.'s neighbors pool with all the vacuum switches, relays, etc..

 

It looks from the picture that your EGR hose was cut, you will want to cap that off as well, you can do that with a brass cap from Home Depot right on the exhaust manifold or weld it shut.

 

Also, if your car has the original distributor, then it is a vacuum retard unit so for the meantime you will want to not hook up the vacuum to it (or else it will run like crap), that dizzy does have a bunch of mechanical advance and while not optimal it does run pretty well without the vacuum.  I actually thought it ran a little better than with the TII dizzy on my car (though a true vacuum advance from an earlier car is really the best way to go in my opinion).

I'm intrigued by that first paragraph. I'm going to read it over and over then nuke it out to see if that's what I want to do. Any links on that?

 

The EGR was cut....soon to be removed....by replacing with a Stahl header.

 

Still pondering about the distributor. Will likely just cap for now.

[FunkyLaneO]

Yup, the tan bundle is all emissions related and only appeared on US cars (most cars had a blue bundle but some '74s had a tan bundle, mine did, I am guessing that your VIN is close to mine) but that entire thing can be replaced with a couple wires.  If you have swapped out to a blue coil (or red) then you don't even need the resistor wire since those coils do not require it, a regular piece of wire will work.

 

When you remove the emissions harness, make note of where you unplug it from the back of the fusebox and plug the wire to the coil there, then plug a second wire onto the fused side of fuse 11 I believe and run that to your choke and solenoid, you can do that with a single wire with 2 ends on it (use a green wire so it is obvious that it is switched power to all who come after you)

 

If I don't make any sense, lemme know, I can send pictures of what I removed and pictures of what it looks like now.

 

Edit: here is a link to someone who documented their desmog http://1leadshoe.blogspot.com/2011/02/smog-harness-removal.html also you can do a search on "desmog" on this forum and you will find lots of info.

Edited May 28, 2014 by FunkyLaneO

[Mark92131]

The water jacket on the cannon manifold is designed to warm up the fuel quicker for better ignition in cold, cold weather.  In Cali, not a big issue.  Don't forget that if you are doing the water bypass, you will also need a two connector water neck from a 320i or a 318/S14 motor, your picture shows the 2002 water neck with the 3rd connection next to the fuel pump.  The idle solenoid replaces the cap for the primary idle jet on the 36/32 (passenger side), on the 38/38 both idle jets are primary, so I don't know it you would need two?  I have a 38/38 on my cab and do experience some run-on when I turn off the key.  You might want to try it without the solenoid installed, and if you have the issue, install it on the passenger side jet and see if the run-on goes away completely, if not, you may need two.

 

If you are looking to replace your distributor to get rid of the vacuum advance, I would recommend the IE replacement distributor, good curve, good price.

 

Thanks,

 

 

Mark

[oldskoolvws]

Thanks. Going out today in the garage. Will update more after. Is this also correct...black / red from coil to starter solenoid?

 

[oldskoolvws]

According to wiring...yes.

 

[oldskoolvws]

Yup, the tan bundle is all emissions related and only appeared on US cars (most cars had a blue bundle but some '74s had a tan bundle, mine did, I am guessing that your VIN is close to mine) but that entire thing can be replaced with a couple wires.  If you have swapped out to a blue coil (or red) then you don't even need the resistor wire since those coils do not require it, a regular piece of wire will work.

 

When you remove the emissions harness, make note of where you unplug it from the back of the fusebox and plug the wire to the coil there, then plug a second wire onto the fused side of fuse 11 I believe and run that to your choke and solenoid, you can do that with a single wire with 2 ends on it (use a green wire so it is obvious that it is switched power to all who come after you)

 

If I don't make any sense, lemme know, I can send pictures of what I removed and pictures of what it looks like now.

 

Edit: here is a link to someone who documented their desmog http://1leadshoe.blogspot.com/2011/02/smog-harness-removal.html also you can do a search on "desmog" on this forum and you will find lots of info.

I'm following this.....I hope it's right...but I'll verify :-)

[FunkyLaneO]

You have a blue coil so you don't need the resistor wire or the black/red wire, replace them with a single piece of wire (preferably green)  the black/red wire allows you to bypass the resistor wire during startup for a hotter spark, the blue coil has an internal resistor so there is no way to bypass it (and really no need).

 

Also I never liked that resistor wire configuration, it you plug the black/red wire into the wrong terminal on your starter it tries to backfeed the starter solenoid and the resistor wire bursts into flames, I preferred the old style resistor and relay, it was a solid design (though probably more expensive and not as tidy looking under the hood). 

Edited June 2, 2014 by FunkyLaneO

[oldskoolvws]

Well, got a little done this weekend.

 

First out with this...yuck. One splice and a few connector replacements but otherwise good shape. Might clean it.

 

 

Back of fuse box and the two wires that need pulling. According to directions, these were replaced. The only replacement difference is that the green and white was moved over to be on the load side and not the line side.

 

 

Making my wires. This will become the green and white. EDIT: Think I'm going to redo the coil side to be stud mount. Much better method...back out it comes, at least one side.

 

 

Getting there. A few more wires to make. Going to custom make the battery cables too. And work on actually trying to get it to start. Anyone know what thread size that big hole is right there?

 

Edited June 3, 2014 by oldskoolvws

[FunkyLaneO]

I believe that is m22x1.5 If you are looking to cap it off BMW used to sell a plug to do just that.