EG Dual Carb: Black Petrol smoke on start up + bad fuel consumption

[LS-TC]

Hey Guys/Girls

the last few days i started up my civic only to find it idling really rough and blowing out black smoke with a strong scent of petrol. or in other words, im running really rich.

it puffs it out in rythm in black clouds and the engine chokes on its self for about a minute then goes back to normal idle.

when i first bought the car, i could pull off an easy 420km's for a full tank.. now im lucky to get 250-300km's and Ive only owned the car for 3 months. changed oil, plugs and so on.

My mechanic dosnt know much about the dual carbs but he said there might be some sticky jets???

I hope someone can shed some light on this problem. I hope it wont cost an arm and leg to fix.

Thanks all

[LS-TC]

btw, i forgot to add, my gf put optimax in last week. half tank only lasted 100km's

no thrashing, just normal driving.

[tRipitaka]

where abouts are u located ?

[MoonSha]

You could try using Nutec Fuel Injector Cleaner. I know, no fuel injectors but it cleans carbies too, changed my kilometreage from 270 a tank(granny) to 350(driving hard) to who knows what if I drive like I did to get that 270.

[LS-TC]

tripitaka, Im in Sydney

MoonSha, ill give it a hit.

its funny coz, i bought the car with no service history, did the 420km's on the full tank, changed the plugs which were f**ked!!, oil, filter, coolant (f**ked thermostat, got it replaced) and when all that was done, it went all down hill..!

[JimBoots]

hey man. im in syd, got the same car and same probs. only jst gopt it b4 chrissy. did a 411km tank and ever sinces its down to like 270-330 max. evey so often it does your problem, my main fault is under exceleration it blows white/greyish smoke. if u cant see it, dont wash your car for a while and if the back of your car gets dirty quicker than the rest your car, you prob have that problem too. been told its my piston rings n valve seals. but keep in mind my car has done 260,000kms
hope this helps. how many k's has ya car done?

[ECU-MAN]

sound slike your pistons in the carbs are sizing up a litttle ot alot
they cant move up or down freely and posibly stuck in the up position meetering a rich mixture to the engine.

to fix , you need to clean the pistons and bores with carby cleaner on both carbs.

[LS-TC]

Jim, my cars done 139,000 km's

ECU-MAN, carbies for cleaned out by taking out panel filter and spray.
do i need to strip the carbies out and clean em?

[TODA AU]

Could be one of the vacuum lines to the "Prince of Darkness" on the fire wall also.

[ECU-MAN]

LS-TC yes, you dont actually need to remove them from the car. you can unscrew the two cylinders off while the carbs are in the car, so you can clean the pistons,

rofl @ TODA AU, Prince of Darkness, lol hahahah, I think that best describes it :)

[A'PEXi]

prince of darkness?? please elaborate

[ECU-MAN]

black box on the right side of the engine bay, with shit loads of vacuum lines going into it

[A'PEXi]

Could be one of the vacuum lines

lol and your suspose to know which vacuum line it is using the guess and check method? :P

[garett]

if you arent sure just take it to a competant mechanic... it sounds like they are running too rich
which is as simple as tuning the carbs, may take him or her 10 mins or an hour depending.
or have them re jetted which is basically replacing all the internals and tuned, expect to pay around 300 ish
carbs are cheap to fiddle with

[[R]]

if you arent sure just take it to a competant mechanic... it sounds like they are running too rich
which is as simple as tuning the carbs, may take him or her 10 mins or an hour depending.
or have them re jetted which is basically replacing all the internals and tuned, expect to pay around 300 ish
carbs are cheap to fiddle with
yeah i agree with garett...

sounds just like you need to get them tuned.

carbies need to be tuned for the appropriate season.

so depending on weather as well may affect the way your car is running.

i know very minimal with carbies but i used to have dual solex's in my old ae86.

u can play with the tuning yourself once you know what you're doing.

all you need is a screw driver! hehe..

[LS-TC]

Hey guys. i been with this mechanic for years. :)

anyways. i done the injector cleaning method, i get 400km's back again woohoo..

BUT...

starting up is always the problem. every time i start up, it blows black smoke for about a minute. now also it makes a stuttering sound like is about to konk out but it wont. it back fired on me a few times. this ONLY ever happens in the mornings where the car has been left to settle down over night or so. after about 5 minutes of me pulling my hair out it drives fine.

my mechanic pulled out the thingies from the carby jets with the needle in it and one of them had a torn gasket. well we thought that was the problem so he fixed that up but nope. still fooked.

im gonna get off the optimax now and use regular unleaded just to see if the higher octane is causing this as well. after about my 2nd or 3rd tank using optimax its been happening.

i got another mechanic who said that the valve guide seals and something about the automatic choke playing up. ill write down everything you guys suggested and well give it a go one by one!

thanks guys

[ECU-MAN]

if its black smoke, its more than likely a fuel problem, from your above post, sounds like your carbys are bleeding fuel into the manifold over night, causing the engine to run rich when you 1st start it.

[keric_02]

sounds like it needs a tune.... but it could be more than that... take it to racq for a car inspection (cost around 120) and they'll tell u exactly what's wrong with it... i know its a bit expensive just for a check up...

[LS-TC]

ECU-MAN SPOT ON!

thats how i feel.. the thing is whats causing it to seap through. i leave it out side work for about 8 hours and start it in the afternoon andit starts up fine. no black smoke. but over night about 12 hours+ then it will do it.

i left it over night at my mechanics and he said he adjusted the choke and something about the fast idle. and said it stopped. but im keeping it there again so he can start it again tommorow morning.

keric, i was thinking about doing one of those car inspection places as well cause i know they bring up any dirt about any car :)

[funkdr]

Old thread i know but for anyone that is experiancing these sort of problems i had similar with my 91 civic after much investigation together with my mechanic we found that the choke "controller" was stuck halfway on
it is a wax filled chamber that when cold puts the choke on heated by engines cooling th wax melts and thus disengages the choke i hope that helps someone it was also a problem on my mates WA festiva i had to bring him to my mechanic before we found it problem solved for him too cause it this used on the new carby engines.

[tommi]

hey hey, i also got an eg twin carby, and i had a similar problem (maybe not the same) and the car would run like a biatch for the first five minutes or so after starting up and would cough and splutter like it wanted to conk out but it didn't, anyways it started happening just after i had changed spark plugs and stuff and it turned out that my spark plug seals were a bit old and some oil was leaking in and fouling the spark plugs (hence the coughing), but after a few minutes of driving it burnt off and would run fine until i parked it for a while and started it up. If it is this then its cheap to fix, if it isn't this then ignore :)

[iamhappy46]

Also, check the Exhaust gas sensor in the exhaust manifold as it would need replacing by this stage(>10yrs old) for any semblance of fuel economy ;) Yes, the twin carb motor is actually ECU controlled using an air bypass arrangement. The air bypass solenoid could also require cleaning with carby cleaner which will help lean out the mixtures too.

The bypass solenoid has a hose to the aircleaner box and another hose that joins the inlet manifold near the head. It sits between the carbs and the cyl head and has a 2 wire plug going into it...

Clean the solenoid, replace the EGO sensor disconnect the battery for a few minutes and it should run like a dream :D

[Jord]

hmm mine does the same smoke blowing things... and i still have ignition problems only thing i want to do with my d15b4 is thro it in the bin bu that isnt an option atm. it is the second time this smoke blowing has happened carby flush fixes the problem but it comes back pretty quickly. the white smoke is normally just the water sitting in the exhaust steaming out ive been told.... last service and tune i took it to the guy for he said smoke for a fewminutes is normal and not to worry bout it but it certainly isnt pretty to seen smoke pooring out of ur car.... goodluck man

[Breezy]

Hey guys. i been with this mechanic for years. :)

anyways. i done the injector cleaning method, i get 400km's back again woohoo..

thanks guys



Whats the injector method? how does it work, does it go in i've the fuel?

[iamhappy46]

I think he means he tried the injector cleaner additive to the fuel to unclog the carbs. It does work but it can also take fuel lacquer off the fuel hoses/pipes and it ends up in the fuel filter or mechanical pump...

[Breezy]

hey hey, i also got an eg twin carby, and i had a similar problem (maybe not the same) and the car would run like a biatch for the first five minutes or so after starting up and would cough and splutter like it wanted to conk out but it didn't, anyways it started happening just after i had changed spark plugs and stuff and it turned out that my spark plug seals were a bit old and some oil was leaking in and fouling the spark plugs (hence the coughing), but after a few minutes of driving it burnt off and would run fine until i parked it for a while and started it up. If it is this then its cheap to fix, if it isn't this then ignore :)

How did you fix it man?

[iamhappy46]

I believe tommi had leaking spark plug tube seals, which was causing oil to kill the spark to his spark plugs.

[Breezy]

I believe tommi had leaking spark plug tube seals, which was causing oil to kill the spark to his spark plugs.

I think oil is leaking into mine too, is there a DIY to fix this problem?

[iamhappy46]

Fit new spark plug tube oil seals.

[dsp26]

I believe tommi had leaking spark plug tube seals, which was causing oil to kill the spark to his spark plugs.

sorry to hijack...

matt... my mates 4age i know has this problem but runs fine here and there. its now developed a permanent misfire as i can see the spark coming out of the dizzy end of the plug corresponding to revs also. this is coz the plug cylinder is drowned in oil right so obviously the spark is FORCED to come out there???

[dsp26]

I think oil is leaking into mine too, is there a DIY to fix this problem?

as per what iamhappy46 said in post below yours.

while your at it just purchase a new seal kit for the head which should include a big one for the rocker gasket and 4 plug "Stem seals" i think they call it... as you gotta remove the rocker cover anyway. i am unsure on price but that kit should cost you somewhere under $100 from repco....

[iamhappy46]

From what you described, it sounds like the spark plug lead is crossfiring onto the spark plug tube? If so, the oil is conducting the electricity better than the spark plug gap of >0.8mm, which is what causes the short. If it has gotten that bad, a new set of leads and oil seals will fix the problem.

The honda spark plug tube seals are a genuine item only...

[dsp26]

From what you described, it sounds like the spark plug lead is crossfiring onto the spark plug tube? If so, the oil is conducting the electricity better than the spark plug gap of >0.8mm, which is what causes the short. If it has gotten that bad, a new set of leads and oil seals will fix the problem.

thanks!!! looks like we can profit from the $750 20v 4age+ ae101 GB we just bought :D

[tommi]

Hey all,

Breezy, well basically it was just a matter of replacing the blown seals, its not an overly large job, just have to pull the rocker cover off (u can respray this at the same time too) and replace them, i got my mate to do it since he's a mechanic and got my tappets re-gapped while he was there so it runs sweet as now, cost is relatively cheap as u onli have to cover the cost of a new rocker cover gasket (from memory around $20-$30) and the spark plug seals (similar price), so if you can get a mate to do it its realli cheap :)

Sorri about the late reply, had a few days off uni so didn't bother to open my computer, hope it helps

[Benson]

time for a b-series engine! :)

[Breezy]

if its black smoke, its more than likely a fuel problem, from your above post, sounds like your carbys are bleeding fuel into the manifold over night, causing the engine to run rich when you 1st start it.

if oil gets into the plugs will this cause black smoke?

[[T][L]]

aye man i got brand new stem value seal to suit your engine forsale...pm me