FAQ - Carbs

[Big CADDY]

well, three of the wires go to the Hal Sender on the distributor. One goes to the Ground, one goes to Hot and one is the signal for the coil. so you don't have to really "incorporate" anything everythihng plugs in or connects except for the signal wire that you wire in with a connector of your choice..

[ftwelder]

I have a 16V MC carb project going right now. I posted a pic of the manifold in progress in the 8V thread. I welded the injector slots in my heads, I also did a gasket match while I was in there. My pendent on my CNC smoked, when the new one arrives, I will post more pics of my manifold.

[iceman2.0]

Quote, originally posted by frankthewelder »

I have a 16V MC carb project going right now. I posted a pic of the manifold in progress in the 8V thread. I welded the injector slots in my heads, I also did a gasket match while I was in there. My pendent on my CNC smoked, when the new one arrives, I will post more pics of my manifold.

kool.

[iceman2.0]

What about venting the gas tank?
I was looking for a vented gas cap, do these exist?

[iceman2.0]

Can we use the wiring diagram with out the timing control unit?
Or is that necessary? My mech. told me that the facet stye pumps work fine, older carbed BMW's came with them from the factory?

[Big CADDY]

you can use it without the timing computer, but you'll be stuck with a static setup. this will work, but once you start advanceing the timing, the harder it will be to start the engine. That's what is nice about the timing computer. it brings the timing back to about stock advance at idle.

[iceman2.0]

What about the pump?

And I just got RickRolled..nice

[Big CADDY]

the facet pumps can work, but double check the pressue readings to not go crazy with fuel pressure. or too little

the price of the facet pumps is about the same as a carter 4070 which is tried and true for the carb setups.

[SpoolinJetta18T]

ok im ready to do the conversion i have the manifold and new webers 40 DCOEs i have the 4070 fuel pump gaskets and lines what else do i need to get this done this is going in a 8v.....

[keithrash]

i'm at the same stage, carbs, fuel pump. do we need to modify the ignition?

[JTiberiVR6]

Just recommendations off the top of my head:

Timing & spark control, slimline fan & radiator, oil breather, modified alternator setup for carb & manifold clearances.

[crazy16v]

Question on fuel pump. with out the ecu i get no ground at the fuel pump realy. do i just ground to the chassis . willl it be on anytime the ignition is on?i mean the small pin on the relay. not sure if it 86 or 85?how can i get it to do like oe and run for alittle then wait to run when cranked?its getting closer.

[iceman2.0]

Quote, originally posted by RaceJetta »

That's the ignitor. That little black thing right under the rain tray on the driver's side. Wire the dizzy to the ignitor, then wire in the MSD between the ignitor and the coil. You need the ignitor because the MSD cannot trigger off the OEM hall sender in the dizzy. Then you will likely need a MSD 8980 timing computer to give your car some low rpm retard. Set the mechanical timing to 30-32 deg BTDC, and then the MSD 8980 will retard it 20 degrees at idle so that it starts and runs easier. Good luck.

I have an unmarked flywheel how do i set my static timing to 30-32° ?
i dont wanna put a degree wheeel on cuz the tranny and engine are one ..in the car.....

[Big CADDY]

get a timing light that you can adjust.

[crazy16v]

Question. if i set the timing is set to 30-32degrees. how hard will it be to start in the morning?

[Mk2enthusiast]

not at all, I run 35 degrees and it'll start in the dead of cold.

You can crank the motor to TDC then remove the inspection hole cover and make a mark with white marker etc. Then you'll spot that using a light

[the12for12]

http://www.dellorto.it/home.asp

[SpoolinJetta18T]

ok i have a 1983 rabbit with an 8v, the engine is fully build .40 over forged piston rods, 280 cam etc etc.....im about to do the weber conversion i have a set of NEW 40dcoe here are my Q's
1. where can i get a cap or screw to plug the CIS injector.
2. do i really need the MSD or can i get by w/o it for now.
3. is it wise to cover the header with that exhaust cloth to keep the heat off the carbs?

[Dirty Jersey]

Im looking for a carb setup for my 97 gti 2.0 8v does anyone have one thanks

[Big CADDY]

Here is a great site that really explains things about weber 45 carbs.

every other site is a copy of what was posted in the begining of this list. which is fine but it doesn't really explain it clearly.

http://www.tjwakeman.net/TR/WeberDCOEinfo.htm

[2mAn]

tons of good info here, lots of repeat questions though! just read before you post people! i just did, it doesnt take that long

anyone know where to get a mikuni rebuild kit? ive got a set of mikuni 35s (i think) and i might use em soon. havent had any luck searching for em.

[SpoolinJetta18T]

ok i got the car running however is running RICH. also what do i do with the return line from the CIS. and how do i adjust the floats? thank you guys


Modified by SpoolinJetta18T at 12:21 AM 10-24-2008

[Big CADDY]

round floats or square?
Dual 40 webers right?

[Big CADDY]

the return line you can just plug up on the tank and pull it out. That is if you are using a low pressure pump.

[SpoolinJetta18T]

Quote, originally posted by Big CADDY »

the return line you can just plug up on the tank and pull it out. That is if you are using a low pressure pump.

yes im running a carter pump so ill plug it this weekend... as far as the floats i really dont know but they are 40dcoe webers

[Big CADDY]

for 40s

DCOE spec = 1.14 inch (29mm+4.5mm).

If the depth is NOT correct, the top plate of the carburetor must be removed. Carefully bend the tab on the float assembly that touches the needle valve. Reassemble and test the float level as before.

copied from:
http://www.teglerizer.com/dcoe/tweakingdcoes.htm

[RedRocketMk2]

great info.
Any pictures of some of your finished setups?
Im running 45 webers on my 2l 16v.
And am planning on "cleaning" up my engine bay. ideas as to mount fuel pump, msd ignition etc. etc. ??
Also i plan on doing some internal work if not atleast head work. how mildly or majorly built are some of your motors? Dyno numbers??
Thanks before hand guys everything is helpful

[Big CADDY]

Esher has a pretty slick mouting area for the MSD stuff. He made a rack behind the glove box.

[SpoolinJetta18T]

Quote, originally posted by RedRocketMk2 »

great info. Any pictures of some of your finished setups? Im running 45 webers on my 2l 16v. And am planning on "cleaning" up my engine bay. ideas as to mount fuel pump, msd ignition etc. etc. ?? Also i plan on doing some internal work if not atleast head work. how mildly or majorly built are some of your motors? Dyno numbers?? Thanks before hand guys everything is helpful

Heres mine and my Engine Specs:
1.8Lt, bored .040
82mm pistons
Head shaved .010
Block decked .025
280 degree Schrick cam
Hi-Rev valve springs
Weber single bore throttle body
Engine rebuilt at Ron's Parts at approximately 110,000 miles (RPIequipped.com)
Engine blueprinted by Techtonics
Battery removed from under hood, placed in enclosure behind passenger seat for better weight distribution
Transmission and Clutch Assembly
210mm Clutch

[Justin 123]

How have you guys gone about wiring up your fuel pumps? I currently have Motronic which grounds the pump through the ecu, but I know older cars relay the fuel pump from the ignition coil and I'd like a setup like that rather than wiring up a switch or something.

Also did you just wire the in-tank pump and the new low pressure pump in parallel?

[SpoolinJetta18T]

i have mine wired up to come on when the car is turned on.

[Justin 123]

What about when the key is in the start position? Can the pump prime?

[Big CADDY]

Mine turns on as soon as I turn the key. I just ran a wire back to the pump and grounded it to the body.

I also put an inline switch under the dash to turn it off if I wanted. It's handy to have that.

[Justin 123]

So you just replaced the ground-to-ecu and straight up grounded it and it worked fine? Any diagrams? Thanks guys!

[SpoolinJetta18T]

i don't have an ECU so i don't have to worry about it...lol