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Hi all, I recently swapped out my 32/36 weber from my 02.  Car was running GREAT!  However, like most of us, I had an upgrade sitting around and decided to install it.  It is a 38/38 DGES.

 

 

I took the 3236 off the car, removed what looked to be a plastic space(1/8 thick) and installed the dges, hooked up the fuel and throttle, reset screws (*seebelow), and hit the key.  At first it started reluctantly... but quickly petered.  Now the car turns over and over then catches, shoots mist/vapor into the air from the carb, makes a terrible noise and wont run...

 

*screwed mixture screws into carb until lightly seated, backed out one full turn.  backed off idle speed screw, then screwed until it touched the throttle, then went a 1/4 turn.

 

I did not rotate the distributor or anything...engine is cold... choke is disengaged...

 

ANyone have any input on this? 

 

Many thanks

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...and is there a puddle of fuel in the intake if you look down the throttle bores?

(after sitting, a float valve can leak or stick open, and flood it, is one possibility)

 

t

 

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Whats the condition of your ignition wires? Make sure they have good separation and there are no cracks or splits in the insulation. The spark could be jumping from one wire to another. 

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Back out the idle mixture 2 1/2 + turns and see if that helps.  Backfire/lean condition, sounds like to me... I just experienced this last week when I swapped a water choked 32/36 for a 'lectric choked model on the '75.  New model was freshly rebuilt and jetted per CD's recipe. Started off with idle mix turned out 1 1/2 turns... It would barely start/run... lean, spitted, and backfired.  Turned the mix screw out and she came to life.  Runs great.

 

Also make sure you have the vacuum ports at the base of the carb plugged or routed properly.

 

Ed Z

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Thanks all! 

 

I will try backing the screw out first... hope its that simple :/

 

The ignition wires COULD be better, but it ran incredibly smooth with the 32/36 I had replaced... so while I will replace the wires soon, I don't think that's the issue...worth checking though

 

As for the fuel volume, yes, there is significant fuel in the intake after a few crankings...  If it IS the float, what is the best way to unstick it?  Is there a method short of taking the carb apart?

 

Thanks again everyone! 

 

 

 

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one more question.  when you back the mixture screw(s) out does that add make the mixture have MORE gas or less?

Edited by blackrado

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backing the screw out = richer

turning it in = leaner

 

yes, you take the top off to check the float.  That is not a big deal.  There is a tiny clip to remove, to release the choke mechanism, where it comes through the top.  I put a little magnet on the tool I use to take it off, so it does not disappear.  Once the top is off, you can push out the float's pivot pin and it comes off with the rubber tipped 'needle' attached.  Peek up inside to make sure it is clean.  A shot of carb cleaner wouldn't hurt either.


While the top is off, you can jot down the size of the main jets, air correctors and emulsion tubes (which sit under the air correctors).  I found that a bamboo skewer worked well for pulling the emulsion tubes out.  I think it is a good idea to pull them, to make sure it is not gunky in there.  I recently pulled some out and there was corrosion happening, with white residue built up.  Those bits want to be nice and clean.  Be gentle with them though.  Once again, the bamboo makes nice cleaning tools, if you shape it accordingly.

 

The pieces that span the top of each barrel are called auxiliary venturis, they should be nice and snug.  If you can wiggle them at all, they need to be shimmed.  They have a little port on one end, which needs to go back together the same way and the shim goes on the other end (obviously).  I recently shimmed mine with .005" stainless, but then measured an aluminum beer can and it was .004", which would have been fine.

 

Do you have the stock manifold?  There are clearance issues with the throttle plates on the 38-38, which require hogging out the inlet on the manifold.  Does the throttle lever work smoothly through the full range of motion?

 

Personally, I am not convinced that the 38 is an upgrade, for an otherwise stock engine; although it makes a lot of people smile, with its peppy feeling pedal.  I am content with the 32-36, after many hours of fiddling with it to get it right.  Installing my 02 sensor will tell me if I actually 'got it right'.

 

This post is sorely lacking photos... so here are some, just for fun.

Gunky emulsion tubes034.JPG
015.JPG

 

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I have a new 32/36 and I feel a bad flat spot at 2500-3000 rpm.

It starts out nice but loses power unless you push thru this point. I hear this is common, any idea how to fix it?

Thanks

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I wonder what jets/tubes came in your new Weber.

If it were mine, I would be curious enough to pop the top off and find out.

The idle jets are removable without taking the top off, but to see the main jets, air correctors and emulsion tubes, you have to take the top off.

 

I have a few old webers (two appear to be knock offs though) and did just that, took the tops off and pulled all the jets, so I could write down what they were.

I now have a list of all of the jets I have on hand, should I need to make a change.

I did make a change when I first got my car.  It wasn't that it ran poorly, but I just wanted to 'freshen things up'.

 

One of the first things I did was to follow c.d.'s advice and put his "jetting prescription" in my weber.

I have been happy with it ever since, aside from a few other little things I've messed with over time.

If you use the search window it is not hard to find the jetting he recommends, which is what I would recommend doing.

 

NEW can be nice, but not necessarily RIGHT.

Open it up and write down what is inside, so you only have to order the ones you don't already have.

Go ahead and remove the air correctors, so you can lift the emulsion tubes out and see which ones they are.

My guess is that there is a pair of F50s installed, which are what I have and they seem to work well.

(c.d. did not mention the tubes, that I recall).

You could also double check the float height while the top is off.

None of this is hard... especially the second time around.

Try and use screwdrivers that fit the screw heads and jets, so you don't bugger them up.

It is shocking how soft they are and I hate seeing them get deformed... it bothers me more than it probably should, but I like it when it looks like nobody's been in there.

There are some very good write ups online for taking the Weber apart, with tons of photos to boot.

Have fun.

 

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Quote

As for the fuel volume, yes, there is significant fuel in the intake after a few crankings...

As Tom says, it's pretty easy to pop the top off, leaving the rest of the carb together.

You then check the float for fuel inside it, and set the float level-

there are several ways, and I forget the number for the 32/36, so you'll have to <<shudder>>

search...

 

Since that's the one thing you changed, I'd be hesitant to mess with anything else just yet.

 

hth

 

t

 

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OK!  Good news!  I got the car running with the 38... idle is smooth as silk and around 1000rpm... engine revs fine above 3000 when aggressively accelerating... HOWEVER, if I feather the idle it will bog and stall.... I need to burp the idle to get it up to about 2200, then I can lay on it and it will climb through to redline. if at any time I ease the throttle, it bogs and dies.

 

My first thought is fuel pressure (currently using stock mechanical).... but being new to carburetors and knowing how many parts there are, I am turning to the forum. Plus, its strange that once it gets up in the rpms it is fine.

 

Again this is a 38 dges (Manual choke converted).  I still have not taken the carb all the way apart to check the jets, but one set says 170?

 

Couldn't still be a float issue could it?

 

Thanks all!

 

EDIT: More info.  The drivers side a/f mix screw does NOTHING to the idle.... the passenger side effects it instantly and will stall the car if I screw it all the way in... makes me think there is a clog somewhere and a good old fashioned cleaning is in order?  Could it be that simple?  Sorry, I know its a bunch of seeming unrelated information.

Edited by blackrado

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And here is a picture of the carb in question. There is some grossness in the butterflies from the previous backfiring issue...

da6ae795010d24e4267258dca8d8b613.jpg

Sent from my iPhone using Tapatalk

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I would take the whole thing back in on the bench and open it up, pull out the brass bits, write down their numbers, squirt everything out with cleaner, check/reset float height, button it back up and run it again.  Don't forget to (carefully) pull the emulsion tubes out from under the air correctors and make sure all that is clean.  number one reason for fuel problems seems to be crud.  maybe make sure the whole fuel line north of the filter is clean as well, while it is apart.  I'll bet you find a chunk of junk. 

this is the biggest nugget I have found

024.JPG

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Yep... something's plugged on the driver's side.  You might be able to get by with removing the driver's side mix screw and idle jet and blast them and the orifices with carb cleaner.  But to address it properly, I'm with Mint on removal and thorough cleaning...(may as well get a rebuild kit at that point (scope creep) and get one with a new power valve, just in case.)

 

How far out did you have to unscrew the passenger side mixture screw to get it to idle? Also, how much input from the choke plates do you have to use to get it to idle? The reason it dies when you feather the throttle from idle is that the driver's side idle circuit is not providing any fuel (clogged up) and the passenger side idle circuit can not provide enough to compensate resulting in a lean condition.  You have better running above 3000 rpms because the carb is no longer drawing fuel from the idle circuits and is getting fuel from the progression and main circuits.

 

Since you replaced a 32/36 with a 38/38...did you increase/hog-out the inlets of the intake manifold to match the bigger venturis? :)

 

Last thing... ummm... that zip tie securing the throttle rod to the carb is asking for problems.  jus' sayin'...

 

Sounds like an easy fix to me. Carbs work best when clean.

 

Good luck!

 

Ed

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