weber question

[CzEcHy]

This is for roodoo mainly, and you testing it on your carb would be great to confirm for me.

I have liquid (in my case carb cleaner), after I pour into the barrals of my weber 38, with the butterflies closed and car off (I was trying to let the cleaner soak at the bottom of the carb), the liquid comes out the primary and secondary throttle shafts. Included is a picture but I pretty much explained it in words. You can see where the cleaner dripped and cleaned the manifold.

Anyway if someone with a weber 38 could pour some carb cleaner to where it pools at the bottom of the carb (above the throttle plates) with the car off, and see if any of it comes back out via the throttle shafts? That would be great.

The manual says there is always a small bit of vac leak from the shafts so I assume liquid coming out would be normal with the car off also since there's no vacum.

Also, that's my linkage setup. No binding, EVER and full travel to WOT. Took me ages to figure it out without the original carb linkage.

http://i10.photobucket.com/albums/a109/czechy/IMG_20111121_123755.jpg

[2oodoor]

It's going to do that! Only unless you had a purpose built supercharger carb.

It does tell me you have your throttle stop idle adjustment pretty good and closed at idle.


What idle jet size are you using by the way?

could be optical illusion but your adaptler plate looks warped...

[CzEcHy]

I'm using the stock jets that came with the kit. I'm buying the jet kit in january then getting a new airbox for it then tuned and dyno'd.


And the adapter plate? I may have it on backwards lol, but its packed with rtv gasket sealer so any small warps or potential leaks should be sealed. I overdid the rtv, a lot. Lol


Other than that it idles pretty smooth at 600 or 700 in D4 with slight vibration of entire car but no major fluctuating idle (maybe a 25 +/- rpm bounce) and around 800 perfectly smooth in N or P. Andddd, I can get over 30mpg easily unless I'm driving above 70 for most of my tank lol



Just need to fix the bogging when stomping on the gas from 0mph. Thinking I need a fpr or jets or the accelerator pump is lacking. Dunno

[2oodoor]

I put 60's in mine and made a world of difference, tremendous amount of improvement of idle and tip in throttle response. All vibrations went away.
Air temp has a massive effect on these carbs so when the weather is in between stages like it is now they run erratic unless you step outside and slightly tweek the idle mix screws. Takes only a few seconds to do that.

I bought some 65's and will try those once the temps stay in the 20 degree mornings and 40-58 degrees peek temp afternoons.

If you have a tach you can use under the hood or a camera/mirror to watch your dash tach, you should try adjusting your 2 idle mix screws using that for highest rpm with the throttle stop idle screw backed off much as it will stand it.

If you never have removed your idle jets for anything, it may be a good idea to do that. They are under the brass screw plugs on the sides of the carb. The tinyest bit of debris can cause issues, just take some carb cleaner spray and blow em out.
You can see if your accel pump jet is doing anything by looking down the carb, engine not running, and operate the throttle.. you should get a nice dual squirt the first time.

[CzEcHy]

Ya jet kits are so expencive that's why I don't have one. If you had a spare kit lying around ill take it :p. I'm almost certain all it needs is a slight jet change. Ill check my idle screws in the meantime, where are they located? Can I see one in the picture I posted?

[2oodoor]

Ya jet kits are so expencive that's why I don't have one. If you had a spare kit lying around ill take it :p. I'm almost certain all it needs is a slight jet change. Ill check my idle screws in the meantime, where are they located? Can I see one in the picture I posted?

yeah Im not sure what the 38 come with standard, if it is 50's then absolutely they need to increase.
No, all I see in your pic is the base throttle stop idle screw, just a piece of it anyway.
The idle mixture screws for each venturi are in front and rear. The brass screw plugs are also in front and rear.
You can buy just individual jets, in fact it is probably better to do so since over half the stuff in the "kit" you would not ever use.

[2oodoor]

http://www.carburetion.com/diags/38DGASDiaginfo.asp

diagram of the 38
# 34, 35,and 36 are the idle jets, plug with seal... look on both sides for the same numbers in the diagram.
#87,88 is the idle mix screw, observe the same are in front and rear although the one side parts are not numbered in this diagram, you can see them though.
http://i23.photobucket.com/albums/b351/Wendy_girl/38.gif

[CzEcHy]

The rear idle jet isnt behind the choke is it?

[2oodoor]

no but they are a neck stretcher to eyeball

[CzEcHy]

Ill start by cleaning them then order some 60s. Are rear and front the same jet? So I can just order 2 60 jets for a dges ye? Also what's the difference between a large and small idle jet (same website of your post)

[2oodoor]

yes you will need a large and a small 60, wierd is even though there are same size they look totally different than one another on the same carb. check yours first before you order them to confirm that is the case with yours because I think there was a mfg change at some point.

[CzEcHy]

Thanks good info. Ill order those as soon as I can, I take it I shouldn't need any other jets?

[CzEcHy]

My idle jets are 45 LOL. So what size would be good? 55? Or still 60. And yes I have one big and one small.

[2oodoor]

honestly I would go with the 55 first, typically youre supposed to move up in increments of five but I can already tell you 50 would be a waste of effort from what Ive experienced as well as read on the web.

55 ran great on my car but it was cold natured and had an idle I just didnt like because I knew these carbs can purr at unreal low idle rpm with no vibrations 60 cured that on this engine I still would go back with 55 when the days are 100 degrees but never in hell would a 45 do for me lol

[cygnus x-1]

honestly I would go with the 55 first, typically youre supposed to move up in increments of five but I can already tell you 50 would be a waste of effort from what Ive experienced as well as read on the web.

55 ran great on my car but it was cold natured and had an idle I just didnt like because I knew these carbs can purr at unreal low idle rpm with no vibrations 60 cured that on this engine I still would go back with 55 when the days are 100 degrees but never in hell would a 45 do for me lol


I want to say I had either 55s or 57s for the idle jets way back when. It has also been my experience that these engines like a REALLY rich idle, even with fuel injection. 55 would be a good choice. Then tweak the idle screws to get the smoothest idle.

C|

[CzEcHy]

Sounds good guys, I just want this Carb to run perfectly, which it isn't to far from.

Will the idle jet change fix my bogging by chance? If I smash the gas to pull into traffic or w.e, it'll basically stall out then after 2 seconds it'll finally go.. same with in N or P if you rev it fast it bogs horribly.

[cygnus x-1]

Sounds good guys, I just want this Carb to run perfectly, which it isn't to far from.

Will the idle jet change fix my bogging by chance? If I smash the gas to pull into traffic or w.e, it'll basically stall out then after 2 seconds it'll finally go.. same with in N or P if you rev it fast it bogs horribly.


No, not really. It *may* improve slightly since it will be starting off from a better mixture but it sounds like you need a larger pump jet.


C|

[CzEcHy]

Hmm, I wonder what size mine is.. guess I can order a bigger one, going up one or two sizes for the pump jet? What would happen if I went to big? Flooding I assume.

Justlooked, I already have a 70 for the pump jet. can you even go bigger?

K another uodate, took pump jet out and blew into every hole, then adjusted float to I guess max level, and no bogging with a driveway test, let's hope it just had a tiny bit of dirt or something. Lol

[2oodoor]

Cygnus the 55 ran fine on the stock A20 but on the B20 it was very finickey with cooler outside temps. Always having to tweak the mixture on days with broad temp differences from morning to quittin time. lol
I think a 57 would be interesting, it didnt have those nor were any in the pack.
Czechy I agree about the accel pump jet, there is a number stamped in that.
I forgot what was in mine. I think 70/// Cleaning it out definatley may help as well as cleaning out the port in the carb it pulls from.
there should be no bog at all on any weber, every one Ive used would break the tires from a stand still no matter the engine. The idle mix adjustment makes a good difference so if you can do the best idle procedure weber publishes it works. I helped me to use a digital tach under the hood because the tune by ear can get aggrivating if you're distracted.

[CzEcHy]

Ya mine was a 70, I cleaned it and raised the float, the bog seemed like it was gone. tuning the idle jets should bring it to 100% no bog, although I'm pretty sure its gone. It must of just been dirty because it used to peel out from a dead stop then one day it started the bogging. Guess it must of just been dirty and cleaning it today must of worked. Can't wait for a road test to confirm it.

So I after I get the idle jets bigger, my weber should be near perfect.

[CzEcHy]

Still has a bog.. would it be my fuel pressure? Maybe the float is to high?

Like I said, I have the biggest pump jet, its a 70.


http://www.mossmotors.com/forum/forums/thread/4190.aspx

Read post 4101, its the 3rd or fourth down.. what is the power valve, couldn't figure out where it was at on that website diagram you posted Guy.

[2oodoor]

it's inside the bowl, I don;t think that is your issue but who knows...

70 is plenty on the pump jet, but im curious does it do this bog even after the car is well warmed up or does anything change at all?
Next time you have the tophat off, get some good throttle body or carb spray with the little straw on it and just shoot it in every orifice you see, and it is a good idea too to do this while youre idle jets are out in that hole as well.
Another thing to spray too is take the adjusting screws all the way out and spray some in there. Count the turns on those so yeah you will have to adjust those over again anyway.
Only other thing to check is ignition timing if it is a long long bog or lull before it gets some rpm.

[CzEcHy]

I always warm my car to full operating temp, winter or summer, before I drive.

I'm ordering the 55s tonight, but I sprayed EVERY hole inside the Carb. Took the top hat off and drained the float and wiped it out incase sand got in or w.e, sprayed everything, got Carb cleaner in my eyes, ran to sink, then continued on the Carb.

When I get the new jets if it still bogs ill call redline and ask their advice.

[2oodoor]

so you are getting a good squirt of gas on both sides of the pump jet I guess? engine off, look inside down throat, pull on the throttle.

[CzEcHy]

Ya, powerful streams straight down into the manifold.

Tried keeping revs at 1700ish RPM while holding the brake ( in drive), and it bogged when I smashed the gas pedal still. So it had air and fuel and still bogged. Any more ideas? Lol

[2oodoor]

Ya, powerful streams straight down into the manifold.

Tried keeping revs at 1700ish RPM while holding the brake ( in drive), and it bogged when I smashed the gas pedal still. So it had air and fuel and still bogged. Any more ideas? Lol

um yeah lol

[CzEcHy]

What?

I'm just saying, while giving it gas with the brake that eliminates a chance of it bogging because the sudden gas and air. And it was when I was at a redlight not my driveway.

I read if the mixture is to lean, it will hesitate or have a flat spot. So I'm hoping the new jets fix it, if not I read the main jets may need to be bigger. I turned the mix screws IN.a turn to see if that helps temporarily since mine may of been out to far (idle was decent tho).

[cygnus x-1]

What?

I'm just saying, while giving it gas with the brake that eliminates a chance of it bogging because the sudden gas and air. And it was when I was at a redlight not my driveway.

I read if the mixture is to lean, it will hesitate or have a flat spot. So I'm hoping the new jets fix it, if not I read the main jets may need to be bigger. I turned the mix screws IN.a turn to see if that helps temporarily since mine may of been out to far (idle was decent tho).


You do really need to tune the idle and main jets before doing anything else. The transition from idle jets to main jets is critical, and if it's not right the off idle throttle response will suck. Considering that your idles are quite a bit too small, I wouldn't be surprised if the mains were too small too. What size are the mains? If they're too small you might as well order new mains and idles now. There are some recommended jet sizes in the Weber sticky (FAQ or HOWTO sections, I forget).


C|

[CzEcHy]

The mains are the ones in the float correct? Its raining so I couldn't check them. If I get 55 for the idles what would be good mains?

[2oodoor]

Barring any other issues with the car I would agree you will do well by getting the idle jets in b4 doing anything else other than recording jet sizes and reading a bit more. There are great threads here and on other forums, I picked up lots of info on Toyota jeep opel and ford six cyl forums. Allcu can do is compare info since each engine responds differently. Cygnus's tuning that was on my carb worked quite well on a stock engine but was tuned for a cam, header, lude tranny. Also his modified intake played a part in that tune, which I'm not using now. You say you're car ran good at first then something happened so what happened ok this is an important piece to this too.

[2oodoor]

Sounds good guys, I just want this Carb to run perfectly, which it isn't to far from.

Will the idle jet change fix my bogging by chance? If I smash the gas to pull into traffic or w.e, it'll basically stall out then after 2 seconds it'll finally go.. same with in N or P if you rev it fast it bogs horribly.

I read into this that this could be timing since it is not being described as hesitation and you say you have a good squirt from access pump. In Park and neutral and u get a delay right. Even so the larger idle jet will help that too I think.

[CzEcHy]

When I change the idle jets, if it still bogs ill take a video lol.

[CzEcHy]

Got the idle jets, put em in, must redo mixture screws settings. Sadly it seems to run near the same as the 45s. Maybe I suck at tuning it lol..

[2oodoor]

Got the idle jets, put em in, must redo mixture screws settings. ..

errrr ya think, you understand why I hope

wish I lived closer i would be glad to give you a hand

[CzEcHy]

Ya me too lol. Ill mess with it some more today since its a fair temp outside and I have time.

But ya, I tried tuning it yesterday exactly how the instructions said but my idle didn't stop vibrating. I'm sure ill get it, or maybe the temp outside is messing it up.


Also, maybe the bog is the main jets being to small? Since slamming the gas would be the idle jets but also the mains since it needs the extra fuel. Maybe I should up my mains 10 more since I did the idles up 10 and not 5.

[cygnus x-1]

Ya me too lol. Ill mess with it some more today since its a fair temp outside and I have time.

But ya, I tried tuning it yesterday exactly how the instructions said but my idle didn't stop vibrating. I'm sure ill get it, or maybe the temp outside is messing it up.


Also, maybe the bog is the main jets being to small? Since slamming the gas would be the idle jets but also the mains since it needs the extra fuel. Maybe I should up my mains 10 more since I did the idles up 10 and not 5.


Did you ever figure out what size the mains are?


C|

[CzEcHy]

I didn't want to remove the tophat of the Carb so not yet. I predict them being small tho.

[2oodoor]

I thought you said you adjusted the float before, if you did then anything else you do is simple on these. The top hat gasket usually stays intact and you won't have to replace those.

I seriously doubt the problem you describe has anything to do with main jet size, not at this point anyway.
You should have noticed a major improvement in throttle response and if you didnt Im suspecting somethiing is wrong with the install or you have some trash in the carb somewhere.
Hopefully when you were slinging RTV everywhere none of it managed to get anywhere near the internals of the carb. RTV does not hold up around gasoline anyway. Only used very super thin sparingly would it be effective only on the base gaskets sealing, if you filled too much with it the worse it would seal longterm.

You may be able to move forward with this as it is but if I were doing it I would start it all over, thats just how my mind works lol.

[CzEcHy]

I believe its running better, it has a bog but its managable if I give it a firm slowish stomp but not all the way. Driving seems smoother, gas test will be starting later to see if my mileage is above 28mpg like before.


If it helps, if I flick the throttle from idle to 2k RPM, it dips below idle when I let off, then raises back to idle. Is this helpful?

I feel my intake gasket may be a problem, so in january I'm getting a bisimoto gasket to keep heat away since those and oem are close in price.

Then I'm going to try some other things like a new exhaust, I feel my cat is prob sealed and melted over time.

Then an a/f ratio gauge, wideband, to tune the carb better.

When I do the gasket ill prob order new base gaskets for the carb and redo that. But my rtv was gas proof rtv, it was expenciveeee.

I made two videos of my idle and the bogging and the carb but YouTube wont accept mp4 so ill have to redo them with my camera and not my phone.

[TotaledTL]

Did you ever determine if the larger idle jets improved it?

[2oodoor]

Im waiting on the video, something is not right if it is dipping back down below idle then recovers up to idle when after you tap the gas to a quick 2k.

[CzEcHy]

Ill redo video today with a real camera.

Wish my phone would of uploaded those videos I already took.


And tl, yes I believe the idle jets did help some parts of the Carb like the idle.

[CzEcHy]

Trying to upload the video now. Will update when done.

http://www.youtube.com/user/CzEcHyorly/videos


The two newest videos are the ones with the bogging and idle dip. Each is like 2 minutes long.

[2oodoor]

Definate sounds like it's set up to run best it can with a vacuum leak it sounds jacked uP I wish I had a vid of one running right it much different sorry I'm posting w ipod

[CzEcHy]

Ill search for a leak better.

Also, my main jets are 142 and air correction jets are 185.

Should I work on the mains also?


Edit - how do you properly adjust the float, the tab that connects the plastic float and touches the brass jet looking thing? No one ever has a good explination lol. Wish it was as easy as the OEM Carb float, a screw.

[2oodoor]

I wouldn't mees with the main jetting for now, I seriously do not believe that is where your problem lies.


Float adjustment on these is done by very carefully bending the metal tab right where it has a bend in it where the needle contacts it.
You have to look very carefully at the needle to see exactly when the piece contacts it then where it actually moves the needle up to close flow.
Never push against the needle into the seat with any thing other than the weight of the needle or float itself or the seat and needle will be damaged.

If you get some carb cleaner spray with a tube you can spray a little around the carb base, the intake mnfld base and see if the idle speed picks up there is your vacuum leak. The spray has to be flammable so what youre doing is actuall richening the mixture thru the vac leak.

Make sure when you do that that you are not geting spray into the carb throat since that would be the defeating the purpose of isolating the enrichment thru vac source (place where there should not be vac, thus a leak)

EDIT
upon listeing to the video on a real computer, the idle actualy sounds pretty good. I am leaning towards the throttle linkage now as to the dip in rpm you have when you give it gas and let off quickley. I really don't like the way your linkage is on there but you already know that lol
The vibrations seem like the exhaust is touching the body somewhere or motor mount out of whack since the whole car is vibrating like that.

[CzEcHy]

I readjusted the float via the tab that touches the SIDE of the brass. Not the tab that touches the ball on the bottom of the brass thing. Correct? Regardless the first time I made it flood, lol at all the black soot from the exhaust. Then I readjusted like the pictures I see online and it SORTA cured the bog. Its still got hesitation or something but nowhere near as bad. I'm wondering if my float was to low?

Also, go make me a linkage like yours. Ill pay you. I hate mine too but it works decent, seriously tho make me a linkage lol. Please

[2oodoor]

probably won't matter where you bend it as long as it isn't touching the inside of the bowl which is another common error with these, don't mess with the geometry of the float pitch it will hang up on the wall or hang crooked ..

[CzEcHy]

Ok so I removed the PCV valve plugged the intake hole and left the hole the PCV valve goes into and the car seemed to run better and it raised the idle some. But my PCv valve is clean and the inside moves with vaccum and the hose is clean. Figured id mention that since it seems weird, and I don't want to drive around without my pcv. It still didn't fix my bog but it seemed to help that dip in my idle a little bit.

With the pcv valve removed, a lot of air pushes out of the hole that the valve was in. Same with the tube from the top of the valve cover. Excess blowby perhaps? Is this bad?

So I'm going to try and fix that somehow and get another distributer and get a fpr and then if that doesn't fix it I'm driving up there and getting you to help fix it. Serious.


I still need you to make me a throttle linkage to :)

[CzEcHy]

Guy read my last post.

ALSO, it bogs when giving gas by holding onto the stock linkage also. So that eliminates the linkage being my problem. I'm going for a vaccum leak or it leaning out, guess ill find out next month when I can get a wideband and a new intake gasket. Going to spray starter fluid everywhere to try and find a leak. Damn rain lately.

[CzEcHy]

Ehh, weekly update..

Redid all Carb gaskets with new rtv, replaced brake booster hose. No other possible vaccum leaks besides intake gasket. Still bogs and dips.

Brand new spark plugs, still bogs and dips.

Repositioned throttle shaft via hit lightly with screw driver handle, still bogs. Removed linkage from carb completly and used finger to flick throttle, still bogs and dips

Unplugged vacuum advance completely, idle raised, still bogs and dips


My idle is virtually smooth as a new car so I rule out vacuum leak. My spark plugs come out after idle a nice tan color (not to rich or lean), so my mixture is spot on basically.


I'm at a loss now, maybe its flooding? Maybe the acceleration jet is to big? The car runs great except that bog, and I wanted this Carb for low end not high end, so that bog has got to go. I must say tho, a 50 to 80 pull takes mere seconds. Passing cars is easy easy, even at freeway speeds. Ill have to get a video sometime.

EDIT 12/30 - that needle idea didn't work either Guy, fuel was just spraying everywhere so can't remove needle. I think my float may be off some, I'm trying to find someone near me with Weber experience to look over things for me but I'm having no luck, guess everyone owns FI vehicles. Tired of standing outside for 1-2 hours a DAY trying to fix this bog.

Also, happy birthday Guy!

[2oodoor]

thanks,
I dont know where you got this needle idea from?
I look at the diagram now and it looks like you have some adjustment there with that, does it have to be screwed all the way in or can you leave it up some?

the kind of hesitation you are describing certainly sounds like an accel pump issue however it could be a transistion issue caused by float level or stopped up hole in the bowl.
You may get away with removing the accel pump diaphragm housing without damaging the pump diaphragm so I would look in there to make sure you dont have garbage in a hole or something. You say you have a good squrit wiht the pump but what is the duration of said squritage.. lol. could still be a bit on the lean side.
Exactly when is the pump lever contacting the pump from when you hit the throttle? is it possible that got bent at some time? you should see a steady stream of gas coming from the pump jet the second you even breath on the throttle, yes and that stream should continue a few seconds as you continue to press the throttle.
Ok , now on the over rich side, even if you got all the squirtage if you happen to be flooding for some reason during this time then you will get the same bog! you would be smelling gas a lot if that was the case, it would be a puddle of gas lying in the manifold just under the carb... waiting to get enough air to move it on into the combustion chamber.
The reminds me of this same issue which I had on a DGS where I goofed and put a DFAS pump jet on it. Guess what, they are backwards so I was not getting a squirt in the primary barrel at all since there was only one opening on the jet going into the wrong barrel.
word to the wise, keep the rtv the hell away from the carb above the mounting flange lol


something else to try for squirts and giggles is to turn both the idle mix screws in a half turn, ignor the idle change and drive it to see if you notice any improvement in bog.. if so then a lean best idle procedure needs the do over.

[TotaledTL]

Why are you using RTV? Don't the directions specify Gasgacinch? I used a spray copper shellac type of gasket coating since I couldn't find Gasgacinch.

Try looking for somebody who works on old VWs as they often used Webers. That's what I resorted to.

[2oodoor]

for those spacers I use permatex hitac , brush in the can type

[CzEcHy]

K..


Number 61 in the chart, the arm thing on the throttle. When connected is opening the butterfly in the barrel closest to the firewall (choke side). Which is causing the small holes in the barrel to be exposed. The enrichening holes I believe. So that barrel is always in the "transition stage" even at idle.

Is this my problem, or normal? The arm is to short so I tried everything to get the butterfly to close fully but as soon as you reconnect that arm it pulls the throttle open and shows an enriching hole but the other barrel is closed during idle completly.

I had the carb off and found this out.


FYI the holes being open indicate the same problem as having the idle speed screw past 1/2 turn Max (mine was completely backedcout when I noticed the number 61 arm thing). according to the booklet and various websites, it causes a rich condition at idle and a stumble off idle to 1800rpm.

I need a longer arm, like mere MM to correct it.

[2oodoor]

OK, if the choke is closed that rod is supposed to hold the throttle slightly open. That is what makes fast idle for warm up until the choke opens up. There also is an adjustment on the carb on the opposite side I think (without having the carb in front of me now) that you can adjust how open the throttle is at fast idle, hence fast idle speed adjustment.

If the choke is opened fully and that rod holds the thottle open still then something is bent or binding or the actural throttle stop screw is holding the throttle open some..

[TotaledTL]

Is the fast idle supposed to remain engaged until the choke heater has been on for a certain period, or is it normal for fast idle to disengage as soon as you blip the throttle?

[2oodoor]

all the ones ive had it disenguages too easy like you describe but the choke is still angled slightly closed to enrich. That said, weber doesnt have much of a step down cut into that cam thing that catches the throttle, usually on other carbs you will see a few knotches that step it down some as the choke opens.
The manual choke weber I had worked out better with that issue because I could gradually taper the choke angle and it worked better for those first few stoplights in the morning lol.

[2oodoor]

Here are some pics of my 38 with the top hat adapter and oem cable linkage tab bolted to the weber linkage tab...
http://i162.photobucket.com/albums/t280/roodoo2/Mobile%20Uploads/0427120730.jpg
http://i162.photobucket.com/albums/t280/roodoo2/Mobile%20Uploads/0427120801.jpg
http://i162.photobucket.com/albums/t280/roodoo2/Mobile%20Uploads/0427120801a.jpg

[2oodoor]

never detailed engine compartment so excuse the lackluster but here is the larger air breather I was able to use after the adapter.
http://i162.photobucket.com/albums/t280/roodoo2/Mobile%20Uploads/0928111326.jpg