hose attached to carburetor

[exoskeleton]

hi guys, im new with 4 wheels. i have a 4k engine on my owner type jeep, i have a question on what is the purpose of this hose attached to my carburetor, it seems like if i pulled if off, there is a very big difference on the idle, if unplugged it will cause a very low idle and the engine will stop, so i have to turn the idle screw a little bit to make the idle higher, im asking because i've been using this owner type jeep with this hose not plugged in, and someone noticed that it should be plug in to the carburetor.

what is the purpose of that hose? obviously it doesn't contain fuel in it.

the hose is pointed with yellow arrows attached form a device going to the carb.. what is that device encircled in yellow?

image attached below:

[dr. d]

hi guys, im new with 4 wheels. i have a 4k engine on my owner type jeep, i have a question on what is the purpose of this hose attached to my carburetor, it seems like if i pulled if off, there is a very big difference on the idle, if unplugged it will cause a very low idle and the engine will stop, so i have to turn the idle screw a little bit to make the idle higher, im asking because i've been using this owner type jeep with this hose not plugged in, and someone noticed that it should be plug in to the carburetor.

what is the purpose of that hose? obviously it doesn't contain fuel in it.

the hose is pointed with yellow arrows attached form a device going to the carb.. what is that device encircled in yellow?

image attached below:

that's the mechanical advancer mechanism. the rubber hose from the carburetor is connected to the throat of the carb. at high engine revs, air pressure in the throat decreases, changing the pressure on one side of a metal diaphragm in the metal gadget on the left, causing the diaphragm to move. the movement of the diaphragm actuates a metal arm that connects to the distributor. the back and forth movement of the metal arm causes the distributor mechanism under the plastic distributor cover to rotate a little. this rotation movement causes the ignition timing to advance a little when the engine revs, and goes back to idling timing when the engine slows down to idling. when there is an air leak anywhere in this system, your distributor ignition timing won't change with increasing rpm, resulting in diminished engine pulling power. this leak can be remedied temporarily by fiddling with the carburator idling screw.

the shortened version: that's the mechanical advancer mechanism. it is connected to the distributor by a metal arm. it is actuated by the carburator's throat air pressure, as transmitted by the rubber hose. changes in the throat pressure, as dictated by engine revs, results in a change in ignition timing (higher rpm, lower carb throat air pressure, advanced ignition). this change results in better utilization of the expanding gases of the burning fuel.

when there is a leak in the system, or when the carb connection is blocked, mekanikos have learned to resort to simply increasing the idling rpm, or advancing the ignition timing permanently, so's their engines can be more workable..
repairing the system is easy. the advancer is cheap. so's the rubber hose. and the blocked air passage can be cleaned with relative ease. have yours repaired, and you'll be amazed at what you've been missing..

[miked]

vacuum advance/retard diapragm....nagooperate under vacuum..connect ka ng vacuum gage diyan para matroubleshoot ang compression, leaks, timing, valve train, etc.

[exoskeleton]

thank you for your reply gentlemen... since my carb doesn't have a diaphragm anymore and the only barrel that is working is the primary, is it ok to remove this hose? is there a change in terms of fuel consumption with these devices connected and / or disconnected to one another?

[dr. d]

thank you for your reply gentlemen... since my carb doesn't have a diaphragm anymore and the only barrel that is working is the primary, is it ok to remove this hose? is there a change in terms of fuel consumption with these devices connected and / or disconnected to one another?

now, i am confused!
what diaphragm are we talking about? the one in the carb's throat, or the advancer's? a carb without a carburetor diaphragm can not function! and your secondary barrel is non-functional? and you say if you remove the tube, the engine dies? but you say your hose is already disconnected but the engine still runs??
please clarify.

[exoskeleton]

im so sorry that i made you confused sir,

yes my carburettor doesn't have a diaphragm anymore. it simply operated via accelerator cable that is connected to the primary barrel. since the primary barrel doesn't require any diaphragm to make it work.. as i had researched about the secondary barrel, it is operated by a diaphragm that is functional in high rpm as high rpm will vacuum the diaphragm and will pull the mechanism on the second barrel to make it work.. In my case, it doesn't have one. only the primary barrel is working. so i just intend to accelerate to the capacity of the primary barrel. my top speed is only around 60kph since my secondary barrel is obviously not working.

if the idle is set with the tube connected, when i remove the tube, the engine kill itself.. so i need to adjust the idle to a little bit higher to achieve a good idle.

if the idle is set with the tube disconnected, when i connect the tube, the idle will go higher.. so i lower down the idle.

yes, i had the tube connected from the carburettor to the mechanical advancer mechanism and my engine still running.

thank you for reading my explanation sir..

now, my follow question is... is this mechanical advancer mechanism has something to do with fuel consumption.. if tube is removed / connected, which case would you think to have a efficient fuel economy?

since this is only a toyota 4k 1.3liter engine, my fuel consumption is 6-7 km/liter .. as im reading some of the threads about 4k engines, they usually had 12-14km/liter... thats a lot of difference, don't you think? given there is no traffic in my route, i changed gear quickly from 1st to 4th gear without reving high just to save the gas, and take note im only running with the primary barrel only so what can i expect.. it will stall if I put down my foot on the accelerator. so just a light touch on the accelerator then shift to 2nd then 3rd to 4th. but still 6-7 km/liter fuel consumption.

[dr. d]

ok.
your carb has two diaphragms: the one in the main throat, and the one in the secondary throat. another name for carb diaphragm is butterfly valve. a metal lever connects the primary to the secondary. it can be repaired relatively easily, if you wish.
as i understand it, your carb is now set at higher idling rpm via idling screw. but when you connect the advancer hose, the rpm goes higher. this means, your advancer is working. keep it connected, and re-adjust your idling screw for a lower idling rpm. with your advancer mechanism functioning, you'll save on gas, and improve your vehicle's performance.
and have your ignition timing checked scientifically. i mean, using a timing light and not just "mechanic's gut feeling". you'll save even more on gas.

there are other diaphragms in the carb.. plunger diaphragm for power, etc. etc.. just let us not get confused..

[sotel]

im so sorry that i made you confused sir,


since this is only a toyota 4k 1.3liter engine, my fuel consumption is 6-7 km/liter .. as im reading some of the threads about 4k engines, they usually had 12-14km/liter... thats a lot of difference, don't you think? given there is no traffic in my route, i changed gear quickly from 1st to 4th gear without reving high just to save the gas, and take note im only running with the primary barrel only so what can i expect.. it will stall if I put down my foot on the accelerator. so just a light touch on the accelerator then shift to 2nd then 3rd to 4th. but still 6-7 km/liter fuel consumption.

sir antakaw naman ng 4k mo , ung 5k ko 10 to 13 km/liter

[Chinoi]

now, my follow question is... is this mechanical advancer mechanism has something to do with fuel consumption.. if tube is removed / connected, which case would you think to have a efficient fuel economy?

Ang purpose ng vacuum hose ay control ng advance timing ng engine. Kapag wala yun vacuum hose ay hindi maganda ang firing ng spark plug ang hihina ang hatak ng engine. So ang tendency mo ay didiinan mo gas pedal para tumakbo ang jeep. Dun tatakaw sa fuel ang makina. So dapat ibalik mo yun vacuum hose sa distributor para automatic ang control.

Mag improve ang fuel consumption kapag naibalik mo yun vacuum hose. Pero sure mag improve kung pa-repair mo secondary barrel diaphragm carb mo or replace mo na lang buong carb..

Ibili mo na lang surplus carb yun nasasayang na fuel.

Meron pa pala another device mag control ng Timing ng engine. Ito yun nakalagay sa loob mismo ng distributor. Ang tawag dito ay centrifugal advance timing mechanism.

[jick.cejoco]

hi guys, im new with 4 wheels. i have a 4k engine on my owner type jeep, i have a question on what is the purpose of this hose attached to my carburetor, it seems like if i pulled if off, there is a very big difference on the idle, if unplugged it will cause a very low idle and the engine will stop, so i have to turn the idle screw a little bit to make the idle higher, im asking because i've been using this owner type jeep with this hose not plugged in, and someone noticed that it should be plug in to the carburetor.

what is the purpose of that hose? obviously it doesn't contain fuel in it.

the hose is pointed with yellow arrows attached form a device going to the carb.. what is that device encircled in yellow?

image attached below:

looks like your ported vacuum installed on the retarder side of the actuator. the back side of the actuator pot has the fitting for the advancer. the picture of the distributor indicates a clockwise rotation of the distributor.. to advance the ignition timing in relation to engine load the breaker plate has to turn opposite that of the distributo rotor. the way it is supposed to operate is to apply ported vacuum to the back side of the advancer/retarder to advance ignition once the throttle plate is at about 20 degrees or more opening to compensate for the engine load

[erj22]

namimiss ko na corolla ko with a 4-K engine...

[exoskeleton]

thanks to all of you guys... its been days to open this thread. its a busy holiday...fixing it but we cant.

another thing I would like to add about this is my idle is gone. there is no way to make the idle lower. if i adjust the idle screw, from high idle to lower, the engine stop suddenly. is there a thing that I accidentally disconnected with connection to the idle? i just changed the jets to lessen the fuel consumption, suddenly it goes like this. so i put back the jets where it has a good idle but it did not work now.

i wonder there is a some kind of a thing with a wire in the carb, what is that?

[dr. d]

thanks to all of you guys... its been days to open this thread. its a busy holiday...fixing it but we cant.

another thing I would like to add about this is my idle is gone. there is no way to make the idle lower. if i adjust the idle screw, from high idle to lower, the engine stop suddenly. is there a thing that I accidentally disconnected with connection to the idle? i just changed the jets to lessen the fuel consumption, suddenly it goes like this. so i put back the jets where it has a good idle but it did not work now.

i wonder there is a some kind of a thing with a wire in the carb, what is that?

it's because your ignition timing is "frozen". the engine idles better at more retarded ignition timing, and runs better with more advanced timing at higher rpm. this change in ignition timing requirements, is what the advancer does.
"thing with a wire.." the only thing in there that resembles a wire, would be a spring..
and there is also a small round ball about 2 mm wide.. if you are not careful, it is very easy to have these spring and ball drop out and get lost when the carb is dis-assembled, without your noticing it. when that happens, your carb won't function..

[exoskeleton]

i gave up.. i brought my owner type jeep to the shop near us... so frustrating... it took only for about 10-15 minutes to fixed it... hayz... the wire thing that is attached to the carb is so called the solenoid.. the mechanic just wired it up and connect it to a positive line and BOOM... it had a very nice idle... and he had also checked the ignition timing using that ignition timing gun or whatsoever... then it started perfectly and ran smoothly... whew... then i tested it ... it now ran 12km/liter... im very happy with the result.... hoping i can have one that ignition timing gun ... an almost a month of adjusting the carb setting... it took only for about 10-15 minutes to a well-experienced mechanic.. that so called solenoid really embarrassed me... but now I learned...


i just wonder what degrees did the mechanic set up my idle by using the ignition timing gun... I watched videos on youtube about ignition timing and it was set to 12 degrees on idle .. and 35 degrees on 4000rpm. well that was a volks wagen i guess... how about 4k engine do you know what is the default degrees on ignition timing on idle and 4000rpm?

thank you guys...

now im gonna overhaul my drum brakes at the rear tires...