engine and drivetrain Need Help! Weber DCOEs Running Rich on Mains. Can't Lean Them Out

[Beach_Bum]

So I dropped the stubborn one into the other hole and it doesn't move freely there either, so I guess I'll be putting that on the order sheet too. Mine as well het the rubber gaskets while I'm at it. I'll check the other carb tomorrow to see if it's in the same condition. I'm almost positive that the one spring is in the same place. So much for buying new carbs to avoid all of this! And here I thought I would be done this weekend. Ha!

And man, do I wish you guys lived near by! These things are driving me insane! Wish I knew you were at the Concours Steve, we were there too.

Ok, I give up for the day. Gotta spend some time with the wife

Edited April 3, 2015 by Beach_Bum

[Stevenola]

If you can get them to seat correctly you may not need new ones because you don't use them.  You just want them to not leak.  If it is not seating, check it for any burrs/out of round that may be preventing it's fit.

 

These are new carbs, from which seller?  Where are they made? 

[Beach_Bum]

Ah, ok. So if they seat down that's a good thing. Sorry, didn't realize you already explained that in your previous posts. It's been a whirlwind of a day. I didn't notice anything that would prevent it from operating smoothly.

New carbs from TEP, both Spanish-made.

Edited April 3, 2015 by Beach_Bum

[Beach_Bum]

Ok, now I'm thoroughly confused

Fiddled with the carbs some this morning. Made gaskets for the cold start block off plates...no more leaks. Took a Scotch Brite pad to the valve that was getting stuck and made it to where it slides freely in place. Starting to get excited that this could be it...

Start the car, warm it up, go for a drive annnndddd...nothing. Same numbers as the last time I drove it. See below:

55f9 idle

115 main

200 air

F16 em tubes

Standard velocity stacks, no filters

Mixture screws 3-3/4 turns out

Idle 12.5-13

2500 rpm cruise 13.5-15 surging

3000 rpm cruise 11-12.5 surging

65-70 mph cruise 11

WOT 12.5-13

Normal acceleration 12.5-14

Now, one thing I did notice today, which I have noticed one other time was that my tach was jumpy (would jump from 1k to about 1300 at idle) and the WB02 was flashing "25" rapidly and periodically between the normal readings. I thought I fixed this when I re-wired my distributor to coil wires, but apparently not.

Is this a dizzy issue? Coil issue? I bought the distributor off Ebay as a "refurbished" piece. It looked newer, and there was no play in the shaft, but other than that I didn't inspect it much.

Edited April 4, 2015 by Beach_Bum

[Guest_anonymous]

You're buggin out on the numbers, throw a 120 main back in.

[downhillwolf]

Please open progression holes, stuck a light inside throat and take a picture of progression holes... So we can determine what is wrong, your carb cover can say 40DCOE151 but who know if it really is...

[Beach_Bum]

Please open progression holes, stuck a light inside throat and take a picture of progression holes... So we can determine what is wrong, your carb cover can say 40DCOE151 but who know if it really is...

Pictures 1 and 2 are left carb. 3 and 4 are right carb:

[Guest_anonymous]

Might I ask, where are the throttles plate in correlation to the progression holes?

[Beach_Bum]

Might I ask, where are the throttles plate in correlation to the progression holes?

1st progression hole on each carb is appoximately 1/4 covered by throttle plates.

[downhillwolf]

It seems to me that there are different size holes... You should get someone with drills or measurment pipes...

[Beach_Bum]

That's just the pictures. All the holes are the same size, and the first one is covered about 1/4 by the throttle plate.

I did a bunch of reading last night from this thread: http://www.classiczcars.com/topic/43089-tuning-40-dcoe-weber-151-on-an-l24/

And have a few things that I'm going to try, including dropping down my air corrector, to help transition sooner. From the thread above:

"You may want to try out a 190 air corrector to see if it counteracts the richening trend at the higher revs.

The air corrector should not be used to correct upper rpm mixture, that is primarily the main jet's job. Enlarging the air corrector will affect the transition to the mains (larger AC makes mains come in later, increased potential for flat spot). The AFR curve at WOT is controlled by the emulsion tube/main choke combo. The "right" combo will yield a flat curve."

I'm also going to adjust for LEAN best idle instead of shooting for 12.5-13, which is something that I believe Steve suggested earlier, but got lost in this long thread. I may even try to play with throttle plate positioning.

More importantly, I'll be doing these things one at a time to see the effect from each change. My goal is to get rid of the surging at cruise speeds and lean out the AFR at highway speeds. I'll report back.

[Beach_Bum]

First test: 115 main 160 air 55f9 idles f16 tubes

Idle screws 4 turns out

Idle: 12.5-13

2500 cruise: 14.5-16 surging and popping

3000 cruise: 13.5-14 surging and popping

3500 cruise: 11.5-12.5

Normal acceleration: 12.5-13.5

WOT: 12.5-13.5

Second test: 115 main 160 air 55f9 idles f16 tubes

Idle screws 3-1/2 turns out

Idle: 14.5-16

2500 cruise: 14.5-16 surging and popping

3000 cruise: 12.5-13 light surging

3500 cruise: 11-12 surging

Normal acceleration: 12.5-13

WOT: 12.5-13.5

Third test: 120 main 160 air 55f9 idles f16 tubes

Idle screws 3-1/2 turns out

Idle: 14.5-16

2500 cruise: 14.5-16 surging and popping

3000 cruise: 13.5-15 surging and popping

3500 cruise: 11-12

Normal acceleration: 12.5-13

WOT: 11-12

Fourth test: 120main 160 air 65f8 idles f16 tubes

Idle screws 3 turns out

Idle: 13.5-15

2500 cruise: 11.5-12 surging

3000 cruise: 9.5 surging

3500 cruise: 9.5 heavy surging

Normal acceleration: 10-11

WOT: 9-11

The bolded portions are what I changed on each test. What I've concluded from all of this is that my car does not like light throttle cruising. It seems that no matter the AFR there is surging and/or popping.

I can defintely live with some of theses numbers (like from test 1), but I can not live with the surging at cruising speeds since this is where a good majority of driving is spent.

[Beach_Bum]

So the more I read about this surging at cruise speeds, the more I think it may be the mechanical advcance distributor I'm using. Especially after reading this thread which Steve and Zinz are both a part of: http://www.bmw2002faq.com/topic/159824-123-ignition-distributorany-info-or-personal-experience/#entry1029122

I know I'm all over the place, so please correct me if I'm wrong.

Without spending $500 on a 123 distributor, is there anything I can try first? Perhaps re-install the 008 vac advance that was on the car previously?

[Stevenola]

Yes if your distributor is suspect swap it out and see if any changes.  I will have a close look at these numbers and see if any ideas come up.

[zinz]

I have a brand new Ireland unit I can send you.

Ed