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fuel coming out of exhaust????

Posted: Sun Oct 21, 2007 9:23 pm
by marcushc
My 91 suzi stock eng carb, runs rough until warm then ok not great. When I am standing near exhaust I get small spatters of fuel? on me. taken in for tune up and no better, possibly broken mechanic!!!!!. Any advice theories appreciated.

Posted: Sun Oct 21, 2007 9:33 pm
by built4thrashing
you will find its actusally condensation (water). you might have a heap of water in the fuel tank or have a leaking gasket somewhere .

Posted: Sun Oct 21, 2007 11:03 pm
by gman79au
doesn't the catalytic converter in the exhaust system produce water when doing it thing?

Posted: Mon Oct 22, 2007 7:48 pm
by BlueSuzy
i have a water problem out my exhaust and soot. weird. also 4th plug fouling out. black as night, have to clean it every 2 weeks

Posted: Mon Oct 22, 2007 8:28 pm
by gman79au
Blue suzy when you do your engine swap pull it down see what condition the oil ring and piston skirt is in on No 4 I would say its oil fowling your plug

Posted: Mon Oct 22, 2007 8:34 pm
by BlueSuzy
yeah i should hey, but it is definatly water in exhaust. it spits on my hand, has no fuel smell but when driving has massive fumes.its shocking. brand new plugs 2

Posted: Mon Oct 22, 2007 8:41 pm
by zooker
BlueSuzy wrote:yeah i should hey, but it is definatly water in exhaust. it spits on my hand, has no fuel smell but when driving has massive fumes.its shocking. brand new plugs 2
Are you saying that you get strong petrol fumes while you're driving? or just a strong exhaust smell?

Posted: Mon Oct 22, 2007 8:46 pm
by BlueSuzy
i think a mix of everything,burns my nose throut etc after an hour drive.... :?

Posted: Tue Oct 23, 2007 11:26 am
by Hybrid
BlueSuzy wrote:i think a mix of everything,burns my nose throut etc after an hour drive.... :?
Yeah I'm in the same boat. I havent checked the plugs for fouling though. Mine spits water out, rough on start/warm up and the exhaust fumes are killing the missus. When I first got it I never noticed but after doing a home carby rebuild trying to fix an idle problem its been happening. I'm wondering if its overfueling for some reason. I do have a new muffler and tail pipe though so maybe the fumes are just a result of the tail pipe location. It sticks out straight back and extends a little past the body.

Posted: Tue Oct 23, 2007 12:19 pm
by smileysmoke
i had to get a dump bit on my zorst as the door seal wasnt that good and it was sucking fumes straight in. sure got some mean headaches beforehand!

Posted: Thu Oct 25, 2007 8:00 pm
by suzimad
gman79au wrote:doesn't the catalytic converter in the exhaust system produce water when doing it thing?
^^^ this is correct.

one of the by products of the cat doing its job is water.

it is pretty much normal for a vehicle running unleaded fuels to spit "black water" while warming up.

its not like the old days of leaded fuels where you can look of the colour of the tail pipe to determine how the engine was running , eg lean or rich.

with the carb engine , what you need to check on startup is the "choke unloader" , its the vacuum operated diaphram that activates the lever that partially opens the choke on startup. take the air hat off the top of the carb and visually check when cold that when you start the car that the choke butterfly slowly opens to about 2-3 mm , if this doesnt happen , you have a problem with vacuum at the line or a leaky diaphram . the vacuum line that operates this unloader also has a "valve" , you can for test purposes remove this valve and attach a hose between the vacuum port and the unloader to test it , although it will open very quickly.

You may also want to check that the choke is fully opening when the water temp is operational temp.

in my experience most carburettor problems are the stem of either incoreectly or non working chokes , or idle circuits getting blocked ..

Posted: Fri Oct 26, 2007 5:01 pm
by ScrawnC
Water is actually a bi-product of combustion. In a perfect world all an engine should emit from the exhaust is water and carbon dioxide. Incomplete combustion is what adds all the other toxins in, which is where the catalytic converter comes in. It's purpose is to burn up the excess and partially burned fuel. Sounds like maybe it is running too rich? You will need a gas analyser to set mixture correctly. And check operation of auto-choke, ie- releasing fully. Hope that speal helps some

Posted: Fri Oct 26, 2007 7:12 pm
by suzimad
In a catalytic converter, the catalyst (in the form of platinum and palladium) is coated onto a ceramic honeycomb or ceramic beads that are housed in a muffler-like package attached to the exhaust pipe. The catalyst helps to convert carbon monoxide into carbon dioxide. It converts the hydrocarbons into carbon dioxide and water. It also converts the nitrogen oxides back into nitrogen and oxygen.