Backfire and Afterfire are different ...

[chinozie]

Hi guys...just to share...

Backfire - Backfire in an automobile engine typically results from various malfunctions related to the air to fuel ratio. Usually, backfiring occurs in carbureted engines that are running lean where the air fuel mixture has insufficient fuel. ("Running lean" is typically a sign of mal-adjusted carburetors or fuel injection where there is not enough fuel for the amount of air).

Common causes of back fires in the intake manifold are bad spark timing, or incorrect (usually lean) fuel ratio.

Afterfire - Afterfire occurs in engines that have an emission system malfunction (air injection system diverter valve), exhaust leak or unburnt fuel in an exhaust system in which the catalytic converter has been removed. When a driver shifts up and lets off the accelerator, the engine has a moment of running rich or with insufficient oxygen. This causes an incomplete burn which causes the fumes to explode in the exhaust system

Video example of Backfire a hick-up during time 1:20 / 1:25 / 1:33 / 1:41 / 1:42 / 2:14 ...and during 3:05 causes an afterfire...unburnt fuel...

[youtube]2CC6M3kOhDA[/youtube]


Correct me if i'm wrong...

Source : wikipedia

 

[blackend]

So it means air fuel mixture is not properly tuning and engine perfomance will drop as well..??

 

[Jordy]

i have almost the same problem with my car too... some how sometime when i shift up my gear... afterfire happends...but not tat bad la...and car fuel smell also but not very strong smell... i'm using the original fuel hose under my car punya which is 1.3cc.... n my engine now is 4age 16valve... should i change my fuel hose to 1.6cc... i heard in another forum saying that tis would cause high fuel pressure n causing unneccesary fuel.... is it true? Thanks a lot

 

[et_box]

fantastic bit of info Master Chin!!! Now i know why my car acts weird sometimes... Just wanna know, how do solve the problem of bad spark timing, or incorrect fuel ratio?

please pardon my noob question...

 

[Jordy]

yes yes how to solve the problem.... i also notice tat most of the 4age has this problem....most of my 4age gang here got the same problem... haish...please help

 

[cybtech]

about the same thing happened to me here, mine, the backfire usually happened most on cold startups, and afterfire when shifting gears or play the throttle up and down few times.
and the exhaust smells almost like petrol. Not to mention that my petrol consumption quite high too.

So i rencon is the O2 sensor caused all this? if it is, changing the O2 sensor will kaw tim this issue?
Coz spark plug i think no problem (just changed not long ago), engine is smooth (no taxi sounds).

Thanks Chin, really great info there, what we without you.

 

[blackend]

i have almost the same problem with my car too... some how sometime when i shift up my gear... afterfire happends...but not tat bad la...and car fuel smell also but not very strong smell... i'm using the original fuel hose under my car punya which is 1.3cc.... n my engine now is 4age 16valve... should i change my fuel hose to 1.6cc... i heard in another forum saying that tis would cause high fuel pressure n causing unneccesary fuel.... is it true? Thanks a lot

better u change immediately ur tube fuel.just go to toyota and order main tube fuel(get the part no first).it will cost rm113 only.but for now,i'm not very sure

 

[Jordy]

thanks for the advise blackend... will get tat done soon...currently kinda busy with work... by the way...u mention that it can be bought at toyota right?? Hope that my mechanic can helpe me change out the tube fuel within 1days time

 

[blackend]

yup,my friend bought that a few months ago at toyota (segambut branch) if not mistaken..:hmmmm:..

 

[Jordy]

thanks for info ....thanks a lot

 

[blackend]

ok back to the topic,..perhaps we need to install SAFC or another piggyback to get a perfect tuning to avoid this problem..:hmmmm:

 

[7Heaven]

good info bro chin! thanks for sharing!:wavey: now i know what's happens to my car

 

[Jordy]

or sud we install air/fuel ratio meter on our car to see either our car air/fuel ratio status???

 

[chinozie]

Huuuu...welcome guys...

It's like this...
correct me if i'm wrong...

Backfire...results from various malfunctions related to the air to fuel ratio...
soo when your car running lean...engine will choke due lack of fuel...maybe can cause a hickup, knocking and the worst can cause engine blow up to lack of fuel !!!

solutions...for those who's using 1.3 fuel railing...please do increase the size, normally stock 1.3 feed fuel rail is 8' and return is 6'...it is not enough...as u all know that it has being discuss way back few years by EFN and all the sifoo here..soo please change it to bigger diameter...which is feed fuel 10' and return fuel 8' ...to avoid the worst part...engine blow up...

how to change it ? ask your mech !!! don't DIY the fueling system if don't know how to...it's very dangerous...

done checking that...if running lean...just increase the fuel pressure, make correction to the air/fuel ratio...by installing FPR (Fuel Pressure Regulator) with meter and AFR (Air Fuel Ratio) Meter...make adjustment until the correct reading...Please do some reading on how to make adjustment and get the correct AFR...mine using autogauge AFR meter...so here's the document -> egauges

bad spark plug timing...distrubutor cap crack, spark plug cable joins crack or malfuntions, faulty engine coil, bad cable plug n so on...

dirty TB, clog fuel filter, not forgetting leaks on fuel and vacuum hose, faulty O2 sensor (can be detected also by using AFR meter) n others possibilities...all related to air fuel ratio...



afterfire - well...mostly cause of running rich...or unburnt fuel ...as mentioned above...straight flow exhaust / muffler tent to get more after fire and visible from the back more then the s-flow type...


soo hope this explains...

 

[blackend]

very useful info we got..credit to bro chin

 

[7Heaven]

yea good one bro chin! million thanks here!

 

[WrX7]

Huuuu...welcome guys...

...........

solutions...for those who's using 1.3 fuel railing...please do increase the size, normally stock 1.3 feed fuel rail is 8' and return is 6'...it is not enough...as u all know that it has being discuss way back few years by EFN and all the sifoo here..soo please change it to bigger diameter...which is feed fuel 10' and return fuel 8' ...to avoid the worst part...engine blow up...

how to change it ? ask your mech !!! don't DIY the fueling system if don't know how to...it's very dangerous...

.........

any idea where to get the part no and where to purchase those?? how much??

would like to change those....cos mixtures too rich...

 

[chinozie]

any idea where to get the part no and where to purchase those?? how much??

would like to change those....cos mixtures too rich...

some wanted to save some buck...they swap the stock 8' feed line into 8' return line ...then install new 10' feed line...

normally they used the copper line used on air-cond system...but i'm NOT TOO SURE bout it...please refer to your mech...or can someone please clarify on this !

what is the correct material used...because it involved fuel high pressure...as you know...

mine already changed by the previous owner...

 

[7Heaven]

yea bro chin, mine was using the copper line.

 

[Jordy]

hmmm...so original 1.3cc feed hose is 8'... if tis is the case..than i'll just swap over my feed line to the return and get a new 10' for my Feed Hose. I've actually asked about tis matter at my mech.... what he told me is ... no such thing lah... bloordy hell