# Weber carburetor on a Jeep 258 I-6 [resolved]



## BelchFire

Anyone here know carburetors? Specifically Weber 32/36 DGEV on a Jeep 258 I-6? I installed one as a fix for the OEM Carter BBD which has a notorious problem for running poor. The Weber was sold as a Jeep kit with everything I need, so I know the application is appropriate. Problem for me is, the Weber doesn't run any better than the Carter! It runs rich, and only gets about 14 MPG with a 5 speed transmission!

I've done TONS to the engine, and ignition trying to fix it, so I feel sure it's in the carb, but if you have any ideas, I'll unload on you with questions (and opinions of that crappy Weber).

Anyone want to tackle this?


----------



## batty_professor

You said carburetor, so I'm assuming no computer, and mechanical and vacuum advance of ign. timing. If the timing doesn't advance properly the engine will be sluggish, and suffer low intake vacuum meaning the carb will misinterpret the engine's demands for fuel. Check for the proper function of the vacuum advance diaphragm, make sure it's connected to the correct vacuum port on the carb. And that the diaphragm is not deteriorated or ruptured. Sometimes an engine belch through the intake will blow the diaphragm. Also make sure the mechanical advance is free, and not rusted/frozen.


----------



## BelchFire

Thanks for the reply! :thumbs up: I've had a timing light on it many times. The timing is good, and the advance is working properly. There are only three vacuum lines left. One to the dist, one to the PCV, and one to teh brake booster. All are tight, and neither leaks. I've tried the dist advance on both ported (where it belongs), and manifold vac, and neither ran normal. 

The following is a copy/paste from another forum entry I made. This post was on a forum specific to Jeeps, so I may be taking some liberties with your initial understandings, but in a nutshell, the OEM jeep carb (Carter, BBD) is notoriously garbage. The Weber I reference below is a kit designed for this application. Read along and you'll see where I am. I sure hope you can help.........

I need some help. Bad.

I'm about to go crazy trying to get my '86 CJ to run right. It all started with the Carter BBD. When it started having problems, and a mechanic told me it was the carb, I knew better than to throw any money into the Carter. So I did some internet research. I considered the Motorcraft 2100 mod, but decide on the Weber 32/36 from a "do it once, and do it right" attitude. That was the worst mistake I've ever made in my life!

I bought a new Weber 32/36 DGEV over the internet, and took it to a professional to have the installation done, because I knew the emissions stuff wasn't very straightfoward. I told him to leave the emissions intact, and just do what he had to do to install the carb.

When I got it back, there were two 5 gallon buckets of fittings and vac line that he removed. AND the carb wasn't right. He said he thought the float level wasn't right. In spite of a new carb warranty, he opened it up anyway, and checked that. Float was fine. He spent about two weeks working on it, and never got it to run right. That was three years ago.

Since then, I've done everything I know how and had another mechanic work on it. Personally, I replaced most of the ignition. Rotor, cap, wires, and plugs; basically everything except the distributor and coil. Didn't fix it. Still running rich; I've tuned and re-tuned probably 20 or 30 different times. Warm choke, ported advance, manifold advance; nothing seems to make a difference. I even tried the Nutter Bypass, and that didn't do it. I tried a new timing set, and that didn't do it. I had to replace the gas tank about 6 months after the Weber carb, so I know the tank is clean, and the fuel is too. New (clear) fuel filter is clean also.

I contacted Weber's technical support. They're good for about three days, and when it wasn't fixed, they quit answering my e-mails. After my last report, I sent three separate e-mails asking "Please" for a response. Nothing. They couldn't tell what was wrong with the carb, and wouldn't make it good. I wrote them off.

The second mechanic said "I can fix the original carb, or this one; either one." I said, "Fine; I don't want the Carter back on it, just fix this one." HOWEVER, he said the engine is tired and it wouldn't do any good to fix the carb until the engine was right. And I agreed to an extent. The engine had over 100,000 on it, and had almost NO oil pressure when hot, it was lightly smoking blue, and had poor compression in no.2 cyl. This was over two years after I installed the Weber. He wanted to rebuild it first, and then get the carb right.

I plan to keep the Jeep right on, so I said "Fine, rebuild it." $2,000 later, it's rebuilt, and has 80 # of oil pressure, but still running rich. The mechanic also said that the carb was the primary reason I had to rebuild. The valves were carbon fouled, as were the rings. That's why it had low compression, and the oil was blowing by. After the rebuild, he's looked at everything, and he can't fix it either.

This is the second Professional I've gone to. These guys both run a shop for a living, and they can't fix the Weber. I HATE that Weber 32/36, are you getting that idea yet?

Since then, I've re-contacted Weber/Redline as if I were starting all over. They answered about three e-mails and dropped me again..... Like a hot potatoe. Their tech support is worthless.

I've got $350 invested in the carb purchase,
over $300 in the carb installation,
$100 for a new gas tank,
$50 for a timing set, and gaskets,
$75-80 for ignition "stuff",
$2000 for an engine rebuild,
$110 worth of jets,
and another $40 for power valve and more jets,
all to fix the initial problem of the Weber running rich out of the box;

AND THIS STINKING WEBER IS STILL RUNNING LIKE %&$#!*!

What can I do about the Weber, and what should I start looking into?

Do any of you have the Weber 32/36?

What jets should I be using?

What lines should still be coming off of the carb (from where to where)?

Remember that I told the first mechanic not to remove the emissions stuff, but he did anyway. (That's a long story, so I just dropped it.) Should I still be using the charcoal canister? What lines should still be present on it?

What else should I be looking into?

Help, PLEASE!


----------



## batty_professor

Wow! That's quite a story. A few questions, general stuff, 'cause I've not personally came across that carb. But bear with me. Does this run rich at all times? Does it lean out at higher rpm? or does it blow a steady stream of black exhaust when you're pushing it, and blubber at the top of the powerband? Does it load up as it idles? The jets mostly effect it above idle, The powervalve affects the entire range. The powervalve is vacuum controlled/regulated. If the base gasket isn't correct, it could interfere with the port through which the vacuum gets to the powervalve. If that gasket has a hole in it where that port is, make sure there's a mating passage (hole) in the manifold at that point. Perhaps there was some plate accessory to be used to accomodate that, that wasn't installed between the carb base, and manifold. What is measured vacuum at idle? and will it make in excess of 20" as it decels?


----------



## BelchFire

batty_professor said:


> Does this run rich at all times? Does it lean out at higher rpm? or does it blow a steady stream of black exhaust when you're pushing it, and blubber at the top of the powerband? Does it load up as it idles?


The only visible smoke I get is on a hot start after it's been sitting for a few minutes (really hard to start). But it's not so much visible smoke as it is a heavy buildup in the tailpipe, and all over the rear of the Jeep. Also a VERY heavy odor of fuel at a stopsign or redlight (it just SMELLS rich), and cruddy fuel mileage. The BBD got 17-18 even when it was going south, so I should be 18MPG plus. I'm getting 17MPG on the first tank after any "trip into the carb", and then 14MPG on every tank after that. I can take the top off the carb, loosen and then retighten anything, and the first tank is back to 17 MPG. Then phffft! (strange, huh?)



batty_professor said:


> If the base gasket isn't correct, it could interfere with the port through which the vacuum gets to the powervalve. If that gasket has a hole in it where that port is, make sure there's a mating passage (hole) in the manifold at that point. Perhaps there was some plate accessory to be used to accomodate that, that wasn't installed between the carb base, and manifold.


Whereas I can't speak for individual ports, this carb was sold as a direct bolt on fit for this application. It came with two adapter plates because of the difference in mounting patterns of the Weber and the OEM carb. Everything was a breeze to install. All passages (for teh power valve) are internal and to my knowledge nothing else is blocked, because there really isn't anything on the manifold except the two barrels.



batty_professor said:


> What is measured vacuum at idle? and will it make in excess of 20" as it decels?


I'm sorry, but it's been a year or more since I've had a vacuum gauge on it, and I just can't remember the figure. It's been rebuilt since then anyway, so I expect the number would be different. I wish I could tell you.


----------



## batty_professor

Hmmmm, 2-barrel, My Mazda used to have a 2-barrel. Have an interesting post for you. http://www.techsupportforum.com/showthread.php?t=21601 SEE post #12. 
And I'm still driving it.


----------



## Volt-Schwibe

let me take a bash at this.

first, one thing i would check for is a small nick or cut on the float valve.

many times, the float valve gets mangled somehow, no matter how careful you are assembling it, or how clean the fuel is.

in a condition like this, you can shut the fuel ratio screw down _*all the way closed and still have a flooding float bowl.*_ (this would act like a sunk float. keep in mind that if the float bowl overflows, the excess runs right into the engine's throat.)

is your choke plate open while the engine is running?

also, did the first mechanic, who changed your carb in the first place, did he leave the charcoal canister in place? and did he connect it to the carb, and the float vent?

also, your carter needed 17 psi of fuel pressure, while most webers require less due to high volume float valves.

if this is the situation, it would also act like a sunk float, causing the fuel pressure to overcome the float and allow the float bowl to flood. you may want to read the documentation for the weber, even if you have to call and ask, and find the appropriate settings for the little tab that you bend to adjust the float. you may even need to change fuel pumps. try to find the fuel pump pressure that the weber is expecting, and try to get a fuel pressure guage onto it.

also, if you have a clogged air filter, the fuel ratio will skyrocket as if you had the choke partway on.

the last thing i can mention, is that one time in my life, i have seen a carb that had a chronic problem with the float sticking while the engine was cooling down.

you could open it and mess with it, and then later on, it was erronerous again.

also found that tapping on it lightly with a block of wood would jar it loose.

unfortunately, your weber probably doesnt have a float bowl window, but luckily, a float cover with a window is available from weber.
this would allow you to simply look and see if the level is too high.

i hope this helps, and if i left anything out, let me know.


----------



## BelchFire

Volt-Schwibe said:


> is your choke plate open while the engine is running?


Volt-Schwibe,
Yes, I've confirmed that the choke is opening when hot, and the fast idle cam is functioning correctly. Truth is, it DRIVES good, it's just the fuel mileage, and the soot all over the tail end of the Jeep that is telling me I've still got a problem.



Volt-Schwibe said:


> also, did the first mechanic, who changed your carb in the first place, did he leave the charcoal canister in place? and did he connect it to the carb, and the float vent?


Yes, the canister is still there. HOWEVER. It's got (about) 4 lines on top. Two are plugged, one disappears under the firewall (the tank?), and one is open to atmosphere. What should be connected to the carb?

There is one line connected to the bowl, but it disappears under the firewall too. Don't know where it goes.



Volt-Schwibe said:


> also, your carter needed 17 psi of fuel pressure, while most webers require less due to high volume float valves.
> 
> if this is the situation, it would also act like a sunk float, causing the fuel pressure to overcome the float and allow the float bowl to flood. you may want to read the documentation for the weber, even if you have to call and ask, and find the appropriate settings for the little tab that you bend to adjust the float. you may even need to change fuel pumps. try to find the fuel pump pressure that the weber is expecting, and try to get a fuel pressure guage onto it.



I had a fuel pressure regulator on it after I first started having problems with the Weber. It didn't change anyting then. I'm going totput it back on, though, just to see if anything runs differently. That's one thing the Weber guys said try (before he quit responding).



Volt-Schwibe said:


> also, if you have a clogged air filter, the fuel ratio will skyrocket as if you had the choke partway on.


Air cleaner is new with the engine rebuild, but it's probably the second or third one I've had "since the Weber".



Volt-Schwibe said:


> the last thing i can mention, is that one time in my life, i have seen a carb that had a chronic problem with the float sticking while the engine was cooling down.
> 
> you could open it and mess with it, and then later on, it was erronerous again.
> 
> also found that tapping on it lightly with a block of wood would jar it loose.
> 
> unfortunately, your weber probably doesnt have a float bowl window, but luckily, a float cover with a window is available from weber.
> this would allow you to simply look and see if the level is too high.
> 
> i hope this helps, and if i left anything out, let me know.


While I appreciate ALL suggestions (really!) I'm just too disgusted with this Weber to spend any more money on it. And I certainly don't like the idea of sending them anymore money. If the float is the problem, wouldn't it run cruddy all the time? With visible smoke, and sluggish performance?

I'll let you guys know how the fuel pressure regulator goes.

Does anyone have a Motorcraft 2100 carb, that's rebuildable? (2-bbl with 1.08" venturis, on a late 70's, early 80's 302, or AMC 304) Jeep people like them for a swap, and if you can find one for $25-30, a kit is only $12-15. They say they run good. Before I spend any money on the Weber, I'd rather try the MC carb. Anybody got one they'd let go cheap?


----------



## Midnight Tech

BelchFire, any way you can post some pics of what's going on under your hood (the carb and charcoal canister, specifcally)? That may help us out a bit right there!


----------



## batty_professor

> Does anyone have a Motorcraft 2100 carb, that's rebuildable? (2-bbl with 1.08" venturis, on a late 70's, early 80's 302, or AMC 304) Jeep people like them for a swap, and if you can find one for $25-30, a kit is only $12-15. They say they run good. Before I spend any money on the Weber, I'd rather try the MC carb. Anybody got one they'd let go cheap?
> 
> 
> 
> Sorry I messed up your previous post, got my mind on too many things today, clicked edit instead of quote, and (GASP!) had to step back to it in my browser, copy and paste. Anyway, I may be able to find one of those old Ford 2-barrel carbs. You're wanting one from the typical V-8 application, right? And not a progressive primary and secondary config like used on four-bangers. I'll see what I can find.
Click to expand...


----------



## Volt-Schwibe

no worries batty, i dug in and repaired them quote tags.

back to the problem at hand though, this is starting to be quite the hassle.

pictures sure would help though.


----------



## BelchFire

batty, no problemo on the edit. I'm a moderator on another forum, and I understand completely. (that's kind of funny :grin: )

I'll see what I can do about pictures. I don't have a digital camera (all my money's gone into my Jeep :sayno: ) If I can borrow one, I'll post pictures. BUT..........

Based on a diagram here, it looks like the Purge Signal (ported vacuum) is plugged at the canister as is the Purge Line (manifold vacuum). The Line from fuel tank is still connected, and the Line from carburetor bowl is open to atmosphere.

HOWEVER......

There is a line on the bowl (the Weber) that disappears under the transmission, headed back to the tank. I have no idea if this line was originally routed from the Carter to the tank, or if it's the line from the canister to the carb, that's been re-routed. I'm diving into the Chilton's manual to try to determine where this line belongs.

The good news is that I have the fuel pressure regulator back in the fuel line, set at 1 1/2#, and it runs OK. I haven't driven it far, but didn't notice any decrease in performance in just 4-5 miles to get sandwiches.

I'll try to drive it to work next week (if it's not raining). That's a 75-80 mile round trip, so I can usually tell in two trips what my mileage is, and the smut is usually back in one trip. I'll be back in touch. And I'm going to work on borrowing a camera.

THANKS GUYS!! :sayyes:


----------



## Volt-Schwibe

yes, that charcoal canister can be a serious problem if it's not connected properly.

and, the 17 psi i mentioned was a typo

7 is the correct number i was referring to.

i hope it runs better with the regulator in place.

either way, let us know.

and, the line that you say disappears under the trans, this is most likely the pump pressure return line, so the pumped fuel has someplace to go if the bowl is not in need of more delivery. 
(should kinda connect to the carb right above the spot where the float valve is inside it.)


----------



## Bald Eagle

Usually there is no return line on a carburetor as the needle and seat shut off the fuel flowing into the carb. The return line is usually on the fuel pump or sometimes as on many chrysler type systems on the fuel filter itself. I suspect that if the weber is a low pressure design about 2 psi, the regulator will help. 7 psi will force fuel past the needle and seat. However in my experience if this is happening the car will not idle as it will flood out, exactly as if the float was sticking. I have seen raw fuel pouring out of the top of a carb because of this.

Webers are very tunable and are a favourite of vintage race car tuners for this reason. They are also a nightmare for the inexperienced person to set up properly. Most techs today are not familiar with carbs of any sort as they were mostly gone by the 1990's . Try to find yourself a performance shop that specializes in vintage or European cars. Check the local papers coming events section or the internet for a local vintage car club and contact them, someone there may have what you need.


----------



## BelchFire

Bald Eagle, you are correct. The return line was (is now) on the fuel filter. I think that was a primary problem. Then the distributor was on ported vacuum when it should have been on manifold vacuum. I think this was a secondary problem, but not as big an issue. Furthermore, the charcoal canister was disconnected, and didn't offer any means to vent the tank (and as a result, the bowl as it was hooked up).

I've got all this fixed now, and I'm driving it today. I KNOW for a FACT that it's setup correctly for the factory lines, and the Weber instructions as a modification. It doesn't have the power that it should, and it doesn't look like fuel mileage is any better (but it's only been 40 miles so far). I'm going to re-set the timing after moving the distributor advance; hopefully, that will improve power and mileage.

BTW, once I got the fuel return line hooked back up, I removed the fuel pressure regulator for lack of space. If it's no better, I'll have to find a way to get it back in the system even if I have to add 12-14 inches of fuel delivery line.

I'll post back; THANKS for looking and helping!!!!


----------



## Volt-Schwibe

Bald Eagle said:


> 7 psi will force fuel past the needle and seat. However in my experience if this is happening the car will not idle as it will flood out, exactly as if the float was sticking. I have seen raw fuel pouring out of the top of a carb because of this.


i have seen this too. exactly the reason i suggested making sure to add a regulator.

although, after more reading, i find that the amount of pressure that a weber wants is variable from 1.5 to 4 psi.

so, if you put it back on, and it lacks power, increase the pressure a half pound at a time, and test drive it after each step up.


----------



## andylv

I'm doing research on replacing the carter on my 87 jeep and stumbled across your posts. Check out these threads hoepfully they'll help. From what I've read so far the weber wants 2.5 to 3.5 psi in fuel pressure. The jeep 4.2L fuel pump puts out 5-7 psi.

http://www.jeepforum.com/forum/showthread.php?t=155115&highlight=weber
http://www.jeepforum.com/forum/showthread.php?t=144489&highlight=weber+regulator

Hope this helps


----------



## BelchFire

*BINGO; I think I'm home free......*

Well, I got the emissions lines corrected, and it ran “differently”, but I can’t say it ran “better”. I drove it to work on Friday, and it ran pretty bad on the way in. I couldn’t even climb a hill. Wondering if I need to re-set the timing after moving the distributor advance from ported to manifold vacuum, I asked a co-worker if I could borrow his timing light. So he brought it back after lunch.

I was reluctant to drive it all the way home (almost 40 miles) if I could check the timing in the parking lot, so I took a look before I started out. I disconnected and plugged the distributor advance line, and GUESS WHAT?! I found the timing set dead on 9º … at idle speed. The under hood sticker shows that the timing should be set at 9º, at 1600 RPM! Once I revved the engine up to (what I thought was) 1600 RPM, the timing advanced to 16º BTDC … a 7º advance condition. There’s the last problem. I reset it to 9º BTDC at 1600 RPM, and it purred like a kitten.

I drove 40 miles back home, and checked my fuel mileage at 18.8 MPG (even driving it in that morning at 7º advanced). I drove some over the weekend, and it’s still purring like a kitten. I’ll know more about the fuel mileage after a put another tank through it, but for now, I’m glad to know the Weber’s going to be OK!

Thanks for all your help and input; I REALLY do appreciate it! :sayyes:


----------



## Midnight Tech

WTG BelchFire! Gonna mark this as "resolved" and leave it for future reference!


----------

