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Weber 32/36 Running Too Rich

63K views 76 replies 20 participants last post by  Frozen Tundra GT 
#1 ·
Recently, I ran my GT, which has a Weber 32/36 DGAV 4D, and it was running so rich there was smoke coming out of the exhaust. I tried screwing the idle mixture screw in all the way, but it made no difference. Do the screws that are midway up the carb body control fuel mixture? If they are loose, will it affect fuel mixture at idle?
 
#2 ·
Are you referring to the rather large brass idle jet screw holders that have O-rings under the head to seal them?

I think I would look for a stuck needle valve. While I had the top of the carb off, I'd go ahead and verify that everything else looked good.

Check the power valve out good while you're there.

Harold
 
#3 ·
Yes, I tightened those down and it seems to run a little leaner, but I want to set the timing and make sure that's set before I run the car anymore. I haven't pulled off the top of the carb recently, but the last time it was off the car everything seemed in order.
 
#4 ·
We pulled this carb and this is the mystery Weber 32/36 DGAV carb that has the thinner shorter idle mixture screw that disappears into the carb, and the idle speed screw that is behind the electronic choke. We pulled the carb and other than those two oddities things look normal. Neither of us however rebuilt this carb or knows where or what it came from. Could be the wrong model and style of 32/36 altogether.

Once you have a timing light we can try to reset the timing and then we can properly adjust the idle mixture and idle speed screws since we know where they are at. The other thing I would be curious to try is disconnecting the fuel inlet line from the fuel pump and putting a new temporary fuel line into a small gas tank with fresh new gas.
We have no idea how long that current gas has been sitting in the tank and if it didn't have a fuel stabilizer put in it that could be causing problems. I did notice when the car was running (running rich) there was a LOT of moisture condensation coming out of the exhaust.

As far as the fan speed, since you know the fan works on the high setting, you may want to pull the dash back and hook up the amp meter to the fan switch. See how much it reads when the fan is on high, and how much it reads on low. It may just be that the fan switch contacts on the low setting are worn out, and nothing is wrong with the fan itself.
 
#5 · (Edited by Moderator)
We pulled this carb and this is the mystery Weber 32/36 DGAV carb that has the thinner shorter idle mixture screw that disappears into the carb, and the idle speed screw that is behind the electronic choke. We pulled the carb and other than those two oddities things look normal. Neither of us however rebuilt this carb or knows where or what it came from. Could be the wrong model and style of 32/36 altogether.
what would be the right 32/36 carb ?
what would be the right jets to use in the 1.9 ?
 
#7 ·
i would like to know if i have the right 32 36 dgev cab you have me :confused::thinking::censored: need to know how to tell and what to look for so i know i have the right one i thought a 32-36 weber is a 32-36 weber the one i have is off a chevy lov /iezzu motor i think that is what is in the lov s it is a after market meaning it did not come with the lov geune weber not a convertion real weber like 1 year old weber
 
#9 ·
The timing is now set correctly. The screw that we thought to be the speed screw I think is the high idle speed screw, before we screwed it in, the high idle speed on a cold engine was ~2300 rpm. Now when it has a cold start, the engine RPM shoots up to ~4000 and it stays that way until you give it throttle and the choke opens. And when it idles, there's a fair bit of smoke, but when you give it throttle, it smokes like a freight train. I took off the number 1 spark plug when I was setting the timing, and it's black.
 
#12 ·
I've never understood this hyper- fascination with carb jetting.
The main function of a carb. is to mix the proper amount of fuel for a given amount
of air flow.

Key word in the last statement is air flow.

So could you install a Q-Jet 4 bbl. carb and make it work on small displacement
engine? I say sure!
 
#13 ·
Yes Wrench but the problem is that this carb was apparently a water choke to begin with, converted by some previous owner to an electric choke along with who knows what other modifications. Including perhaps jets that are too large and allowing too much fuel through thereby throwing off the ratio of fuel/air mixture. We're trouble shooting and trying to figure out why his car is running so rich. The carb and incorrect jets could be one of the things contributing, or not, and we need more info so we can scratch this off the list and get closer to resolving this problem.
 
#18 ·
Two pics should answer much . . .





 
#19 ·
Thanks Tekenaar. Unfortunately the Idle Speed Screw that you point out on your pic is not in the design of the carb Alex has. There's a fixed metal stop where the screw should go. And the Idle Mixture screw does not have a spring, it is much thinner screw, with a thinner thread and the top of the screw head screws in below the hole. No remaining screw head sticks out.

This is what had us stumped in the past. I'm guessing this is some weird off model that was designed that way. We have found the Idle Speed Screw behind the (now) converted electric choke.

BTW how did you get such a brilliant shiny carb??? paint? powder coat?
 
#20 ·
Thanks Tekenaar. Unfortunately the Idle Speed Screw that you point out on your pic is not in the design of the carb Alex has. There's a fixed metal stop where the screw should go. And the Idle Mixture screw does not have a spring, it is much thinner screw, with a thinner thread and the top of the screw head screws in below the hole. No remaining screw head sticks out.
Can you remove the metal stop and replace it with an adjustment screw & spring? I picked up a Weber some time back I believe with a idle mixture screw similar to what you are describing with the exception that it had a plastic plug (emission thing) that I had to remove before I could adjust it.
This is what had us stumped in the past. I'm guessing this is some weird off model that was designed that way. We have found the Idle Speed Screw behind the (now) converted electric choke.
I believe you are referring to the fast idle screw for cold start idle speed w/choke.
 
#26 ·
glad to see I'm not the only thermoquad fan. Careful with the bowl.
 
#29 ·
That may temporarily help diagnose a the problem you're looking for. Also the brake booster hose from the manifold to the booster should also have a one way valve installed on the rubber hose. If it's missing that may cause a problem. I don't recall seeing one, but then again I don't recall checking for one on your car either.
 
#32 ·
I read a few articles that came up on a Google search on New and Used Car Listings, Car Reviews and Research Guides - AOL Autos

Here is what the article titled "Does Gas Go Bad" said:

"Water Contamination

Condensation can form inside your gas tank and lines from heat cycling. Fuels such as E85, which have a high concentration of ethanol alcohol, may be even more susceptible to water contamination, as ethanol likes to draw moisture out of the surrounding air...
Water, of course, does not work too well as a fuel in an internal combustion engine.
It will cause hard starting and rough running until it's purged from the system. It can also contribute to internal rusting of the gas lines and tank. The resultant scale and small particles can create a true nightmare, sometimes requiring the replacement of the gas lines and tank at considerable expense.

How Do You Identify Bad Gas?
One way is to eyeball it. Oxidized fuel often turns darker over time and may even smell sour. You can check stored gasoline by pouring some into a clear glass container and comparing it side-by-side with known fresh gasoline. If your old sample looks noticeably darker than the fresh gas, you have strong evidence the gas has gone bad."


I can certainly attest when we started the car up and I had you rev it up and keep the idle at about 1500 or higher for a few mins... there was a lot of moisture coming out of the tail pipe and not just fumes! The seller said the car may have sat for 4-6 months since it was last filled with gas, and the gas tank is about 1/2 full !!!

My suggestion of course was to get some fresh (high octane gas) and hook up a new fuel line from the small 2 gallon tank to the inlet on the fuel pump. Start the car up and if it runs better and smoother that would be another indicator.
 
#33 · (Edited)
Yup, do what Neil just said.

Condensation drips out of my exhaust every time I start it up. With an accompanying cloud of white smoke. I'm also probably running a little rich. I suspect I also have a leaky exhaust valve guide on one cylinder which let's oil trickle down into the exhaust port after it's been sitting. It doesn't stop me from driving it and it goes away after start up. One GT I bought 25 years ago had been sitting for a couple years and the first drive around the block sent so much white smoke into the neighborhood that the fire department showed up because a little old lady on the next block thought someone's house was on fire. It took like 10-15 minutes to stop smoking and then it never did it again. Bad gas turns reddish orange and you'd be amazed how fast goes bad. I have a scooter that refused to start or even kick when I filled it with 6 month old gas. I put new gas in and it started right up. A poster here on the site told us that the water sinks and stratifies out of modern gas with ethanol. You could be drawing almost pure water out of your tank.

Just for peace of mind you should pull the hose off the tank and let it all drain out, taking with it as many rust crumbs as will come out. At least you'll be able to rule fuel out as a cause. It's extremely likely that you'll need to clean and line your tank anyway, unless the PO did it, so consider draining it as a first step.
 
#35 ·
You can either run the motor till it runs dry, or you can use a pump to remove the fuel, then there's the messiest way, which is to let it drain out the bottom fixture, on the driver's side rear of the car.
 
#36 ·
Water vapor is a by-product of the internal combustion engine. Notice 'weep' holes in the bottom of stock exhaust mufflers to allow for drainage, water blowing out the exhaust on first engine start of the day, etc. Once the engine and exhaust system get up to normal operating temperatures it's not as noticeable unless you have other issues.

In the good ol' days when gas was gas (without additives that weren't mandated by the EPA or CARB) and it acumulated moisture, we added some magic stuff to the tank (main ingredient-alcohol) to get rid of the moisture. Water doesn't mix well with pure gas so it separates. Ever notice gas or oil spills on bodies of water float and burn? The alcohol combines with the water in our fuel tanks and this combination will burn.

Less condensation occurs in FULL fuel tanks than those low on fuel.
Side benefit is it helps to prolong the life of in-tank pumps commonly used in modern vehicles not to run around almost empty for a significant amount of time. The fuel acts as a coolant for the in-tank pumps.

HTH,

Harold
 
#39 ·
Drain your tank at the tank, don't try to "pump it out" through the car's fuel pump. You don't want any of the old funk in your tank/pump/lines to go through your system. Most Opel gas tanks are shot at this point and need to be relined or replaced. Observe how smoothly the gas pours out. If you see the flow sputter and drip, you probably have crud in your tank. It wouldn't be a bad idea to replace your rubber fuel lines and fuel filter before attempting any starting with your new carb. Get a see through filter, so that you can observe any crud building up.
 
#40 ·
Me and Neil made a lot of progress today!

I had siphoned the gas a few days earlier through the fuel filler cap, and we drained what was left of it today by disconnecting the line from the bottom. We poured in a gallon of fresh 91 octane gas, disconnected the double fuel lines for the old carburetor and added a single line to the new carb from the clear inline filter (installed by previous owner). Neil primed the carb, it started for a few seconds and stalled. Then I cranked it for a few seconds to let the carb fill up and it fired right up, with no use of the electric choke. I guess the old carb Gil let me have works fine once I made sanded the bottom of the carb flat. It idles well at around 1000 rpm, although it's still running rich. No more clouds of smoke though! :)

I want to see if there's a vacuum leak somewhere that's causing the carb to run rich, which I want to find by spraying carb cleaner around any intake or carb seals.
The oil leak has seemed to go away, although now the original water pump has decided that now is was the time to start leaking. :banghead: Oh well, it was probably time to replace it anyway and they're not too expensive.
 
#41 ·
Water Leak... Before replacing anything when you get around to removing the radiator and fan blade you should check the bolts on the water pump. They should be tightened down in a star pattern. If memory serves correctly there should also be two bolts that are shorter than the rest. If any of these bolts were not tightened enough this could have caused a leak. Over tightening of a bolt and stripping the thread could also cause a leak too.

But like we discussed a new water pump would probably be best. $59 with new gasket from OGTS.
 
#44 · (Edited by Moderator)
Chances are your local auto store will not have a water pump in stock. If you want to save a few $$, and you can wait a couple of days, rockauto.com has a Gates pump with metal impeller for under $24. With shipping you'll get it for around $33. I've noticed that rockauto uses several vendors. When you make a purchase from them, take notice of the shipping charges. Plan purchases of multiple items from the fewest vendors so that you can keep the shipping costs to a minimum.
 
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