my carb sweats

BUZZ

Well-known member
I'm have problems with my carb and my 2 into 1 adaptor condensating. I've looked through the old post and haven't found a way to fix this. It's in an 82 fox body so there a no provisions for running hot water to it. Does anyone have any Ideas? Its causing water to form in my carb bowl and my adaptor sweats really bad, I pulled my carb off the other morning after coming home from work and had about 1/2 a tsp of water on the inside of my adaptor.
The weather has been in the low 30's high 20's when I leave my house or come home from work and this area always has high humidity.
 
My old '73 Comet used to have a piece of tin with a duct outlet that fit over the exhuast manifold. It had a duct that ran up into the snorkel of the air cleaner where there was a vacuum actuated valve the closed when the engine got warm. It basically directed heat off the manifold to the carb to help prevent carb icing etc. Did the stock '82's have such a critter?
Doug
 
Not on this one it just had a 1946 holley and egr. I pulled the egr as soon as I got the car because half of it was unhooked already.
 
My 82 Cougar has the heat riser to the snorkel. Still works and I haven't had any problems with my 1946 although it doesn't get very cold here.

Additionally right now my EGR is disconnected because the diaphragm is bad. I've lost about 5mpg because of it. I'm not driving it much but I do have to get a new EGR. I normally get 19-20 in local (slow) driving. 22-24 on the highway. I can't pass an emissions test without it and it'll run too hot in the summer. The exhaust gas actually cools down the cylinder temps. Strange but true.
 
I would assume that an EGR system would have the same if not better effect of warming the carb up. If I recall correctly, once an engine is warmed, the EGR system and the retarding spark function of the dual advance vacuum distributors are shut off.
Doug
 
The problem I'm having is with a Demon 350 cfm carb and a transdapt 2 into 1 adaptor. All my EGR is gone along with my stock aircleaner, I had a old motorcraft 2150 on it for a while but wanted to upgrade to the demon, when I first installed the demon it ran perfect, the next day the weather dropped to the low 30's ( it was in the 60's the day before ) and my car would bog on take off. This made me think that I need to adjust the acc. pump. I did for 3 days, I changed acc. pump cams, squirters, and every other thing I could think of. Then on 2 very cold, wet days my car got to where it didn't want to run at all, when I'd get to the parking lot it would be missing and you could hardly keep it running.

While messing with the carb one day I noticed small water drops when I moved the acc. pump arm, so I took it for a drive and pulled the carb as soon as I got to my shop. When I got the carb off I saw 2 large thumbnail size drops of water on the inside of the adaptor and water all over the outside of it and the bottom of the carb.

So far I've pulled out my two 1/4" spacers one under the carb and one under the adaptor and put in thin gaskets, pulled my pcv hose from the intake adaptor, and ran it to the bottom of the carb, changed my vac. source from timed to full vac for my dissy, and installed a large clear fuel filter inline to be sure I'm not getting water from my fuel. So far its doing better but I'm sure that when the temp drops again it'll be back.

The only reason I can figure as to why I didn't have all these problems with the 2150 is because it's acc. pump is on the side where as the demon is on the bottom, and the weather is just now starting to get really cold here.
 
66 Fastback":16n0v21b said:
If I recall correctly, once an engine is warmed, the EGR system and the retarding spark function of the dual advance vacuum distributors are shut off.
Doug
My understanding is that EGR is off until the engine is warmed up, and then it operates during cruising rpms.
 
It's sounds like what we call carb icing up here, although it's not cold enough down there to form the ice.
There have been some discussions on this issue in the 240-300 forum so you might want to search or ask there.
If there is that much humidity and cold down there I'd put some gas line anti-freeze in the tank to evaporate the condensation that could form.
 
My understanding is that EGR is off until the engine is warmed up, and then it operates during cruising rpms.

You are correct, my boo boo. :oops: And that would make sense. The timing is retarded by retard side of the dual vacuum advance in order to heat up the engine quicker. During that time NOx is not a problem since the engine is not warm. EGR is used to cool the combustion temp and reduce the formation of NOx.
 
66 Fastback":276swryp said:
The timing is retarded by retard side of the dual vacuum advance in order to heat up the engine quicker.
I thought the dual part of the vacuum can hooked up to a ported deceleration valve, for when you take your foot off the pedal, it then retards to save fuel?
 
I am not all that familiar with the deceleration valves. I know some carbs have deceleration dashpots for use with automatic transmissions.

Manufacturers started using the ported vacuum source in order to retard the spark timing and shorten the time it took for the engine to warm up. The vacuum switch tee was used in conjunction with the distributor's dual vacuum advance canisters as another emission control device. While the engine was warming up, it sent full manifold vacuum to the retard side of the distributor canister. This retarded the spark advance resulting in higher combustion temperatures which had the effect of warming up the engine faster and burning some of the otherwise unburned hydrocarbons during the warm-up period. Once the engine coolant was warm, the vacuum switch closed off the manifold vacuum port signal at the tee, and very little or no vacuum was sent to the retard side of the vacuum canister.

I don't know whether or not the retard vacuum canister was also used in conjuction with a deceleration valve. The emission era carbureted car that I owned was equipped with manual transmission, and in 1973 they had not finished all of the bells and whistles that later emission era cars had on them.
Doug

By the way, I have always been curious if your name "Jackfish" had anything to do with the oil sand "Jackfish" project going on up in Canada.
Doug
 
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