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Unread 09-02-2011, 02:41 PM   #211
SJ85CJ7
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Quote:
Originally Posted by mcmud View Post
When we see the mixture screw having little or no effect to idle quality it is a real good indicator that the throttle plate is opened too far... allowing enrichment fuel to be drawn past the plate.

If we see fuel spilling from the axillary (booster) venturi its a real good indication of a float out of adjustment/bowl overfill and the primary throttle plate being open, drawing fuel from the well.

Remember that during the initial tune procedure that the idle speed screw is to be set to a maximum of 1-1/2 turn in once the tip contacts the stop lever and within that point that no vacuum signal is seen at the 'S' nipple at idle speed.
In order to set this screw you must first maintain the choke plates open while you open/close the throttle plate in order to clear the fast idle linkage from any interference.

If the carb is jetted near to the need of the engine you should then see result with begining at say 3 to 3-1/4 turns out with the mixture screw and work it inward from there. In this thread you will find the process of a lean best setting clearly defined.

If you haven't already done so, check on the float setting.
Pulled the top off the carb and adjusted the float (was too high) running better now also found that my curb idle screw was not set right "butteryfly was open too much" set that to a nice 700 rpm idle mixture screw now working, now I have to buy a vacuum gauge and then I'll get that set right.

Still not running right, PITA to start - a good overhaul/rebuilt is in order.

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Unread 09-12-2011, 01:17 PM   #212
SJ85CJ7
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finished the rebuild, still running like poo. Popping thru the exhaust, hold my hand over the intake and it does run better.. someone said thats the sign of a vacuum leak? I don't know I've covered everything during the install that could cause a vacuum leak, replaced all the vacuum lines did one hell of a job mounting the adapter plate for the weber. Now I'm lost and sitting staring and drooling trying to figure out this carb
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Unread 09-12-2011, 01:26 PM   #213
uptillnow
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Quote:
Originally Posted by uptillnow View Post
I see you bought this used. There is ussually nothing wrong with that except the "Weber" 32/36 DGEV for use on a Jeep ussually starts out with the jetting something very close to this:
.75mm Primary idle jet
.60mm secondary Idle jet
1.45mm pri & sec main fuel jets
1.70mm pri air jet
1.60mm sec air jet

Follow mcmud's basic set-up, about 1 1/2 turns in on the idle speed screw with ZERO vacuum at the "S" advance port or ported vacuum, then you can find the lean best idle. This should get you in a place to start diagnosing any problems you might have from this point forward.
There are many people who are very well versed when it comes to tuning a real "Weber".
Good Luck
UPTILLNOW

Soooo, what did you come up with??

(hijack??)
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Unread 09-26-2011, 10:02 PM   #214
mulliflier
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Swatson/McMud,

Awesome thread, I've been reading a ton on here and learning quite a bit. I've also tried to teach myself some and read Passini's book on Webers and basic carb theory. Let me start with some background first so you know where I am coming from.

Bought an '84 CJ-7 back in '04 from a buddy of mine, with the intent to do a 3-month, $3,000 rebuild. Of course, the most I knew about cars was very basic, but I figured I could teach myself as I went. Well, got overly involved with it, had the frame-off and everything, and then I started deploying (military). 4 deployments, a wife and 2 children and 7 years later, and I finally get the dang thing back together and running (at least rolling, running may be an overstatement.) It's been a fun rebuild and I've learned a ton, but still learning for sure on the fuel delivery side of the house.

So, getting back to the carburetor, I rebuilt the 258, it's now a 261, but fresh with only 600 miles or so on it (you can run that engine pretty far even with the carb tuned like crud.) Stock intake, Weber (Solex) 34/34 DGEV from Quadratec (bought too long ago to return for a 32/36), DUI, etc. Well, the carb out of the box was a little finnicky, but had it running at least well enough to wheel when I was stationed at Ft. Lewis, but I never had it tuned properly and couldn't get any real power from it. Had the stock jets, etc. Moved up to CO, elevation 7K feet. Made the mistake of reading the Fjuerico post or whoever he was, and started messing with the jets. Now I've got myself a little dorked up and looking to get this thing tuned properly once and for all.

So, here's my basic setup:
I6 bolted to stock Luk clutch to SM465, Dana 300, AMC 20 and Dana 30 front, 4.56 gears (originally re-geared for the old T-5, but when it bit the dust I went to the 465...I know, super low gearset for this) and 33x12.50's. Oh and Holley FPR set at 3.5 psi (I know, psi at idle in the driveway ain't the same as in the dirt with the pedal on the floor, any input on this setting would be appreciated as well.)
DUI set at 10.8*, will move it back to 10* for the next round of tuning.
Tried a variety of jet sizes, 40/35 idle and 140/135 run left me with no power in 4th to climb over 40 mph unless flat or downhill.
Now set with 40/35 idle and 145/140 run jets, can't get it to idle too well, hops between 620 and 710 or so rpm with the mixture screw 4.5 turns out. Still not much power.

I read the entire thread and going to go back and start from scratch, complete with sanding the plates and loctite, finding lean best idle, etc. but wanted to ask you gentleman for your best guess as to what jets I should start with and what I should have on-hand to make the adjustments. I would like to order the jets in one whack so I don't get nailed on shipping.

I tried the math that McMud had, 34 mmx4 - 136 run jets x .42 = 57 idle jets, obviously I don't think I can get them exactly that size but if that seems (despite the altitude) like a good starting point I'll head that direction. The thing I've noticed recently, heading up into the mtns, is that as I climb the carb seems prett sensitive, and her characteristics really change with the altitude (climbing as high as 10-12K if you head over the passes is my goal, but have been up to about 9-10K recently.)

Gentlemen, your help is greatly appreciated. I will be printing this thread and putting it in my manual for future reference. Where did you guys learn all this stuff? Any books you could recommend? I'd like to get smarter on fuel delivery.

Also, somebody mentioned not to use the little air cleaner that comes with the weber (solex) carb...any recommendations on where to go with that?

Thanks, and have a great week fellas!
Sincerely,
Mike M.

Last edited by mulliflier; 09-26-2011 at 10:06 PM.. Reason: forgot info
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Unread 09-28-2011, 07:22 PM   #215
mcmud
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Mike,

If you have the idle jets that were set when the DGEC arrived, start with reinstalling them, post their sizes and the results of the attempt to dial it in with them. Often times the DGEC users have benefited with increasing the size from those it shipped with, with your elevation that may not be an option so try what you've got.

The one thing that we Weber fanatics can share is knowing that my carb is as near the same as the other users of the same series, as near as rigorous quality control standards can allow. My screw hole threads are started at the same position, the progression holes should be spot on identical to his or hers.

As far as I can tell, the DGEC owner doesn't have that same privilege. These carbs seem and react as though they are built to a different standard so yours may be considered unique from the next DGEC. This may be the reason that as far as I know there is no detailed guideline to follow with tuning this one.

The point in this is that until you find that point that your throttle plate is as near closed as is possible and still allow a nice smooth idle (speed is of no major concern here) via the flow allowed at the mixture screw you cannot go on to justify making a fair assessment of the mixture strength.

Swatson454 has posted an excellent process to determine the adequacy of the slow run system, just beyond the onset of the progression system, use it.

In times past I have found that DGEC users are thrilled with results of having the throttle plate set at 1-1/8th turns inward at the speed screw and the mixture set to a range between 2-3 turns out from lightly seated.

The DGEC will not faultier with a lean misfire as the Webers do, so during the lean best setting procedure start at say 3-1/2 out on the mixture and work it inward until an undesirable (too slow)idle speed is found and then outward a bit to achieve at least 550-600 rpm. All this while the speed screw was set and I suggest you always leave it set at that original position...1-1/8 turns in.

With respect to your elevation careful consideration, qualified judgment should be given to the changes necessary. I won't attempt to help with that. Uptillnow can and I'm quite certain that he will, rely on his skilled judgment, we do.

In the mean time while awaiting jets reset the originals and give the tune a try.

That random idle speed can be attributed to an uncontrolled air leak, it could be due to the secondary plate resting unclosed and may be due to a snag/bind in the accel/throttle linkage.

Manuals; Although the pages will begin to fall out at say 15 years you've named what I consider the overall best of the lot, Passini's Weber Carburettors Theory, Tuning and Maintenance.

Weber Carburetors by Pat Braden is a another fine one, much simpler reading than Passini, you'll recognize many of his remarks comments and theory in this one.

Pierce Manifolds Tuning Manual is another very good resource and the quickest to read.

If you decide to go with the OEM breather shop for the Weber 32/36DFEV series air filter adapter.

You've presented a very nicely detailed inquiry, along with what reads as an inquisitive nature and desire to whip this cat.
You can help us better understand this thing, we'll sure try to help you help other DGEC users.
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Unread 09-28-2011, 09:15 PM   #216
mulliflier
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Mr. McMud,

Thanks very much for your reply, I will reset the jets and give it another whirl. It looks like it will be either tomorrow or late Friday before I can get to it, what with work and all. And also since the lower pulley decided to depart the engine on my last ride in the hills (apparently it had a crack in the groove), I need to run around town tomorrow finding a new pulley, v-belt, and lower radiator hose.

Also, thank you very much for the vector on the books, I'm going to look for them this evening. I enjoyed Passini, he had a unique writing style, and dry British humor always makes me laugh. Unfortunately, carburation is still very complicated to me, and going from broad theory to detailed application is a haul. I'm still somewhat baffled by emulsion tubes and air correctors, but I'm sure I'll get there eventually (with this carb, I may get there whether I like it or not.)

Ironically, all this talk about the 32/36 and the 38/38 are making me want to sell the 34/34 and just go with a real Weber. A purchase made in ignorance...

I'll post when I get the old jets in and get some data. I'll plan on recording timing, mixture, idle, vacumn (this one may be trickier for me but I will try) and temperature - is exhaust temperature at idle a data point that I can use for any type of insight? Or header temperature?

Take care gentlemen, and thanks for the reply, I know the time spent on this forum is voluntary and that you all have other things you could be doing besides helping us knuckledraggers along.

Sincerely,
Mike
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Unread 09-29-2011, 03:59 AM   #217
John Strenk
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Ironically I learned all about carburation on Webers which was carried over to other carburators as well.

Someplace I scanned in those Passinni books someplace.
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Unread 09-29-2011, 05:23 AM   #218
SJ85CJ7
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My problem solved, p/u a used Weber 38 with had idle jets 60, main jets 145 and air jets 170. Carb looked like turd when I first got it cleaned off and sprayed in barrels with cleaner threw it on and engine runs 100% better, plus wired up a MSD 6A. Anyone want to buy a used Weber 32/36?
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Unread 09-29-2011, 05:53 AM   #219
Matt1981CJ7
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SJ85CJ7,

Did you ever figure out what jets your 32/36 has?

Mike M,

First off, thank you for your service. Secondly, we're practically neighbors!! I live near Elbert, CO, which is only about 20 minutes from CO Springs.

I'm not the mechanic Terry (McMud) is, by a long shot, but I can usually muddle my way thru. If you need any help getting your CJ dialed in, I'd be happy to help in person. It would be the least I could do for you, considering the sacrifices you've made for me and this country.

Good luck, sir.

Matt
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Unread 09-29-2011, 07:03 AM   #220
SJ85CJ7
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Primary idle jet .45 Secondary idle jet .50 , primary air tube is 170 Secondary air tube 160, main jet for the primary barrel is 140 and the main jet for the secondary barrel is 137

Quote:
Originally Posted by Matt1881CJ7 View Post
SJ85CJ7,

Did you ever figure out what jets your 32/36 has?

Mike M,

First off, thank you for your service. Secondly, we're practically neighbors!! I live near Elbert, CO, which is only about 20 minutes from CO Springs.

I'm not the mechanic Terry (McMud) is, by a long shot, but I can usually muddle my way thru. If you need any help getting your CJ dialed in, I'd be happy to help in person. It would be the least I could do for you, considering the sacrifices you've made for me and this country.

Good luck, sir.

Matt
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Unread 09-29-2011, 08:24 AM   #221
John Strenk
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Quote:
Originally Posted by SJ85CJ7 View Post
My problem solved, p/u a used Weber 38 with had idle jets 60, main jets 145 and air jets 170. Carb looked like turd when I first got it cleaned off and sprayed in barrels with cleaner threw it on and engine runs 100% better, plus wired up a MSD 6A. Anyone want to buy a used Weber 32/36?
How much?
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Unread 09-29-2011, 12:59 PM   #222
SJ85CJ7
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How much?
I have it up on the club web site I belong to for $100 plus any shipping fits nice in a USPS standard mailing box
weber-2.jpg  
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Unread 10-05-2011, 02:51 PM   #223
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I've spoken at length with David and had the opportunity to study with him last month. The information that's bottled up in his brain is staggering. Here's a short clip of him discussing emulsion tube tuning that I thought you may enjoy.



Shawn
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Unread 10-10-2011, 07:24 PM   #224
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During tuning my weber 38, I have taken off the top plate many times. Everytime I have reused the float gasket. Should I replace the gasket?

Im asking this because when I accelerate with medium to heavy acceleration, the exhaust smells rich for a moment and then the smell goes away.

Also today while going over a tall speedbump slowly, the engine bogged down.

Im guessing that as the jeep accelerates or goes over a bump, the fuel gets sloshed around. And since the bowl gasket has been reused many times, the fuel is seeping into the venturi. The carb has been in use for about 8 months and I have probably taken the top of the carb off about 10 to 15 times in total.

Does anyone have any input?

Thanks
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Unread 10-11-2011, 09:10 AM   #225
mcmud
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While I must admit to never going into one or reusing a cover gasket that many times, I do know that if you'll toss that gasket into a pan with a shallow covering of motor oil each time you remove the cover it will sure help keep it conditioned for reuse.

I recall seeing your tailpipe/odor thread and must say that was one sooty set of black holes, then in that same thread I saw inside another Weber38 users pipe to what appears to me to be the leanest ever.

Maybe you're outrunning that odor at the pipe, tipping in the main circuit too soon?
Drawing fuel from the enrichment holes at idle?
Is your float set to spec?
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