Help! Exaggerated FC. 4af

[eto_ako]

Auto ko po ay ae92 na may 4af na makina.
Fuel consumption in city driving environment: 5km/L.
Newly overhaul po sya pati head. Kasama nga din ang carb pero ang takaw sa gas.
Do i need to buy a new carburetor o mas ok na magpaoverhaul ng carb?

About sa carb:
Walang tagas ang AAP nya, nasa tamang level ung fuel dun sa may glass sight. Ang idling, sa cold engine naglalaro sa 500rpm, pag naginit na nasa tamang 800rpm idle sya. Wala namang abnormal event kung ibibirit. Ok din pag naka aircon. Yung mga vacuum lines di ko sure kung tama pero mukhang ayos pa naman, walang mga leaks. Sakit lang talaga sa bulsa ng konsumo para lang naka v8 lol. Ang hindi ko lang alam testingin kung bukas ba yung big butterfly nya kahit naka idle kaya lumalamon ng gas o iba ang sukat ng jettings. Ayoko namang buksan para i check ang jettings kase baka hindi ko maibalik lol. Naka 2x balik narin ako dun sa gumawa ng carb pero walang pagbabago kaya bottom line ayoko na ipagalaw sa kanila.

Location ko po ay laguna pa, kaya kung may maisu-suggest kayong magaling talaga sa carb na makakatulong po sa pag diagnose mas makakatulong talaga. TIA

[lowslowbenz]

How did you know na wala vacuum leaks? Your choke flap maybe stuck to the closed position. Are you using the stock air filter, or aftermarket na? Did you own the car since brand new, or second owner ka? Any idea on the primary and secondary jet size?

Carbs are very simple fuel metering devices, but an inexperienced pair of hands will fcuk it up almost easily.

[jick.cejoco]

Auto ko po ay ae92 na may 4af na makina.
Fuel consumption in city driving environment: 5km/L.
Newly overhaul po sya pati head. Kasama nga din ang carb pero ang takaw sa gas.
Do i need to buy a new carburetor o mas ok na magpaoverhaul ng carb?

About sa carb:
Walang tagas ang AAP nya, nasa tamang level ung fuel dun sa may glass sight. Ang idling, sa cold engine naglalaro sa 500rpm, pag naginit na nasa tamang 800rpm idle sya. Wala namang abnormal event kung ibibirit. Ok din pag naka aircon. Yung mga vacuum lines di ko sure kung tama pero mukhang ayos pa naman, walang mga leaks. Sakit lang talaga sa bulsa ng konsumo para lang naka v8 lol. Ang hindi ko lang alam testingin kung bukas ba yung big butterfly nya kahit naka idle kaya lumalamon ng gas o iba ang sukat ng jettings. Ayoko namang buksan para i check ang jettings kase baka hindi ko maibalik lol. Naka 2x balik narin ako dun sa gumawa ng carb pero walang pagbabago kaya bottom line ayoko na ipagalaw sa kanila.

Location ko po ay laguna pa, kaya kung may maisu-suggest kayong magaling talaga sa carb na makakatulong po sa pag diagnose mas makakatulong talaga. TIA

Newly overhaul po sya pati head.
if the engine is newly overhauled, the cylinder bores and the piston rings are not fully mated yet and there is still too much friction from the cross hatched hone. the bearings are probably still breaking in too. try to give your re-virginized engine some time.

[GTi]

Since overhaul, you will observe break in procedures again. The FC should improve as the kilometers pile up. Though you should probably also check if something is dirty or clogged.

[eto_ako]

ok boss. so far 1 month palang ang sya since overhauled running approx 500kms. any tips sa breakin procedures?

eto ang pictures ng carb sir, kung may makikita man kayong unusual sabihin nyo lang po, thanks :D

IMAG0807Medium_zps8ada85bc.jpg Photo by jasonaladin | Photobucket

[kompressor]

Read your plugs. Malamang covered in soot yan given your FC.

Lean out the mixture muna during the first 500+ kms of the break-in process. (sakal jets and retard ignition timing ng konti). After at least 500-1000kms, bring back the jettings to factory spec and adjust ignition timing to factory specs as well. Before adjusting the jettings (leaning out and back to factory spec), make sure you have no manifold and vacuum line leaks. Mura lang naman per foot ang mga vacuum lines. Buy the ones na meron nang ply.

[Ammiel Barlis]

Auto ko po ay ae92 na may 4af na makina.
Fuel consumption in city driving environment: 5km/L.
Newly overhaul po sya pati head. Kasama nga din ang carb pero ang takaw sa gas.
Do i need to buy a new carburetor o mas ok na magpaoverhaul ng carb?

About sa carb:
Walang tagas ang AAP nya, nasa tamang level ung fuel dun sa may glass sight. Ang idling, sa cold engine naglalaro sa 500rpm, pag naginit na nasa tamang 800rpm idle sya. Wala namang abnormal event kung ibibirit. Ok din pag naka aircon. Yung mga vacuum lines di ko sure kung tama pero mukhang ayos pa naman, walang mga leaks. Sakit lang talaga sa bulsa ng konsumo para lang naka v8 lol. Ang hindi ko lang alam testingin kung bukas ba yung big butterfly nya kahit naka idle kaya lumalamon ng gas o iba ang sukat ng jettings. Ayoko namang buksan para i check ang jettings kase baka hindi ko maibalik lol. Naka 2x balik narin ako dun sa gumawa ng carb pero walang pagbabago kaya bottom line ayoko na ipagalaw sa kanila.

Location ko po ay laguna pa, kaya kung may maisu-suggest kayong magaling talaga sa carb na makakatulong po sa pag diagnose mas makakatulong talaga. TIA

Sigurado ka ba sir na 4af makina mo. 4Afe engine is fuel injected and does not use a carburator as far as i know. Baka 2E yan

[kompressor]

Meron ding 4A-F aside from 4A-FE. Carbureted ang 4A-F twin cam 16 valve which is installed sa mga 89-92 na 1.6GL local variants. 2E (1.3 12 valve sohc) yung installed sa mga XL tsaka mga XE. Nung panahon na ng AE101 (big body sa street lingo) kinabit ang 4A-FE which is the twin cam 16 valve fuel injected version na installed sa 1.6 GLi na local variants.

Stated dito yung difference ng 4A-F vs 4A-FE http://en.wikipedia.org/wiki/Toyota_A_engine

[jick.cejoco]

Sigurado ka ba sir na 4af makina mo. 4Afe engine is fuel injected and does not use a carburator as far as i know. Baka 2E yan

the valve cover in the picture is that of 4af, it has only one cam pulley. if it had two separate pulleys for the intake and one for the exhaust valve it becomes 4ag/4age/4agte

[Ammiel Barlis]

the valve cover in the picture is that of 4af, it has only one cam pulley. if it had two separate pulleys for the intake and one for the exhaust valve it becomes 4ag/4age/4agte

Thanks for the info. Never knew this. You really learn something everyday. Thanks again

[eto_ako]

Read your plugs. Malamang covered in soot yan given your FC.

Lean out the mixture muna during the first 500+ kms of the break-in process. (sakal jets and retard ignition timing ng konti). After at least 500-1000kms, bring back the jettings to factory spec and adjust ignition timing to factory specs as well. Before adjusting the jettings (leaning out and back to factory spec), make sure you have no manifold and vacuum line leaks. Mura lang naman per foot ang mga vacuum lines. Buy the ones na meron nang ply.

ang lean settings grayish ang tips diba? sige sir i li-lean ko muna habang meron pang 500+kms na natitira :D. Mga hanggang ilang rpm po ang max na apak ko ngayon? sa ngayon kase hanggang 2k lang ang max ko.

[Chinoi]

Have you tried checked the Timing of Engine. Baka hindi naibalik sa dati after overhaul. Be sure na gamitan ng Timing Light ng mechanic para sure. Hindi pwede hula hula . Dito kasi malalaman kung gumagana din yun Vacuum advance sa Distributor.

[kompressor]

ang lean settings grayish ang tips diba? sige sir i li-lean ko muna habang meron pang 500+kms na natitira :D. Mga hanggang ilang rpm po ang max na apak ko ngayon? sa ngayon kase hanggang 2k lang ang max ko.

lean setting is maputi yung magiging result ng plug reading. stoich is parang rusty brown and rich pag dark. Hindi lang pilot jet ang ina-adjust. Pati main jet and secondary jet palitan babawasan mo (palit with a lower number but not too much, for example let's say from 83 to 75 pilot and from 165 to 150 secondary tapos less pihits naman sa pilot jet). Yes kailangan mo talaga ng timing light para iretard and ibalik sa tama yung ignition timing. Please do note na yung binigay kong jettings ay example lang and hindi talaga para sa 4A-F.

Oh, check mo rin pala kung nagana yung vacuum advancer. Easiest way to check although hindi rin dapat conclusive is to make higop higop the vacuum line connecting to the vacuum advancer "flying saucer" while the distributor cap is removed. Pag pumipihit yung assembly, then it is working (again hindi conclusive kasi pwede ring pigil or kulang sa pihit).

Ang factory spec ng ignition timing niyan is 10degrees BTDC at 900rpm with vacuum lines plugged.

[eto_ako]

lean setting is maputi yung magiging result ng plug reading. stoich is parang rusty brown and rich pag dark. Hindi lang pilot jet ang ina-adjust. Pati main jet and secondary jet palitan babawasan mo (palit with a lower number but not too much, for example let's say from 83 to 75 pilot and from 165 to 150 secondary tapos less pihits naman sa pilot jet). Yes kailangan mo talaga ng timing light para iretard and ibalik sa tama yung ignition timing. Please do note na yung binigay kong jettings ay example lang and hindi talaga para sa 4A-F.

Oh, check mo rin pala kung nagana yung vacuum advancer. Easiest way to check although hindi rin dapat conclusive is to make higop higop the vacuum line connecting to the vacuum advancer "flying saucer" while the distributor cap is removed. Pag pumipihit yung assembly, then it is working (again hindi conclusive kasi pwede ring pigil or kulang sa pihit).

Ang factory spec ng ignition timing niyan is 10degrees BTDC at 900rpm with vacuum lines plugged.

wow, salamat sir kompressor. this weekend siguro ill try to make higop higop ng vacuum advancer :D
kelangan ko pala talaga buksan ang carburetor para palitan ang jettings, hindi lang pala sa a/f screw naa-adjust yon. kakailangin ko siguro ng photographer para hindi malito kung pano ibalik, good thing andyan ang misis :D

malaki po ba ang impact sa FC kung faulty ang vacuum advancer?

[Chinoi]

Ang factory spec ng ignition timing niyan is 10degrees BTDC at 900rpm with vacuum lines plugged.

Diyan mo ma-determine kung gumagana vacuum advancer. Saksak bunot mo vacuum hose sa "flying saucer" sa distributor then observe yun tunog ng engine kung magbago rpm.

malaki po ba ang impact sa FC kung faulty ang vacuum advancer?

Sobrang laki. Takaw sa fuel ang kotse mo at mahina hatak.
Subukan mo tangalin yun vacuum hose sa advancer at barahan yun hose. Then test drive mo. Makita mo ang diprensya.

[eto_ako]

bali dalawa pala yung hose ng vacuum advancer, taas at baba. pag sa taas ang hihuhugot ko nagbabago ang idle tapos ramdam mo talaga na may vacuum papasok, tapos yung hose sa baba mahina yata or almost walang vacuum... normal kaya ito? TIA

hindi ko pa nata-try yung higop higop na advice ni sir kompressor, nag quick test lang ako bago umuwi.

[Chinoi]

tapos yung hose sa baba mahina yata or almost walang vacuum... normal kaya ito? TIA

Normal iyan. Magkaroon lang ng vacuum iyan umaandar ang sasakyan or may load na iyon engine. Ibig sabihin malakas ang vacuum kapag naka stationary ang kotse at hihina ang vacuum kapag naka bwelo na ang kotse. Na-adjust ang btdc ng distributor para bumagay sa load.

[eto_ako]

UPDATE:

I think I found the culprit. Nagpa-adjust ako ng timing na ginamitan ng timing light for P150, and I think malaki ang improvement sa FC. I need more km pa para ma-vindicate ang naging solution, pero so far malaki talaga ang improvement. I'm guessing 8km/L, city driving, from previous 5km/L.

So, sa matataas ang FC try nyo muna ipa-check ang timing.

Thanks nga pala sa mga tumulong, specially kay sir chinoi na nag-suggest ng timing

[kompressor]

Ayus na yan for a 20 year old carbureted engine. Even yung 4A-FE averages 8kms/liter in the city especially with traffic.

[eto_ako]

Update:

Na-excite lang pala ako... 6km/L pala ang fuel consumption sad... minsan nga 5km/L pa, wala pa palang nagbago...

next to check is jettings... ano bang stock size ng jets nito? di ko sya mahanap sa google... baka dahil sa kalumaan...