one cylinder is dead

[duskylim]

Sir:

I you suspect a dead cylinder (for whatever reasons), then the simplest possible confirmation is a compression test.

Have this done by a competent shop and you should be able to see the readings for yourself.

Note them down and compare them.

If as you say, there is one dead cylinder, then the compression reading for that cylinder will be very much lower than the others.

As a rule of thumb, an engine is considered UNTUNEABLE if there is a 10% or greater difference in the compression reading between the cylinders.

A good shop should also be able to tell you the standard compression pressure of your engine.

Now, if the news is BAD - that you actually do have a dead cylinder - the next step is to determine whether it is a valve or piston ring problem.

If it is a piston ring problem it will be accompanied by BLOWBY - that's gases leaking past the piston rings into the crankcase.

Blowby will cause the pressure in the crankcase to build up, and the excess pressure will usually carry with it a lot of oil vapor - which tends to come out of the dipstick hole and the top of the valve cover assembly (the BREATHER).

You will be able to see, smell and almost taste this oil vapor when the engine is running - it will come out of those places I mentioned.

If there is LOW COMPRESSION but NO BLOWBY, then it is rather unlikely you have blown piston rings.

The obvious candidate then is leaky valves.

Another good test to perform AFTER the compression test is a vacuum gauge test.

Attach a sensitive and good-quality vacuum gauge to your intake manifold, where it can sense full vacuum.

Every time the defective valve tries to close, the needle on the gauge will drop sharply.

A leaking head gasket is the easiest one to diagnose - if there is a leak you will be able to hear a strong whistle, or gas release every time the engine fires - parang 'air brake' yung tunog.

Just to be thorough check the spark plug of the 'dead' cylinder again - is there any sign of combustion residue or carbon on it - if YES then it's firing, so it must be getting gas.

Is it coated with oil - if YES then it's quite likely your piston rings are blown.

If it is clean and not covered in carbon or residue - then you may have a defective injector.

Hope this helps.

Best Regards,

Dusky Lim

[sirkosero]

Sir:

I you suspect a dead cylinder (for whatever reasons), then the simplest possible confirmation is a compression test.

Have this done by a competent shop and you should be able to see the readings for yourself.

Note them down and compare them.

If as you say, there is one dead cylinder, then the compression reading for that cylinder will be very much lower than the others.

As a rule of thumb, an engine is considered UNTUNEABLE if there is a 10% or greater difference in the compression reading between the cylinders.

A good shop should also be able to tell you the standard compression pressure of your engine.

Now, if the news is BAD - that you actually do have a dead cylinder - the next step is to determine whether it is a valve or piston ring problem.

If it is a piston ring problem it will be accompanied by BLOWBY - that's gases leaking past the piston rings into the crankcase.

Blowby will cause the pressure in the crankcase to build up, and the excess pressure will usually carry with it a lot of oil vapor - which tends to come out of the dipstick hole and the top of the valve cover assembly (the BREATHER).

You will be able to see, smell and almost taste this oil vapor when the engine is running - it will come out of those places I mentioned.

If there is LOW COMPRESSION but NO BLOWBY, then it is rather unlikely you have blown piston rings.

The obvious candidate then is leaky valves.

Another good test to perform AFTER the compression test is a vacuum gauge test.

Attach a sensitive and good-quality vacuum gauge to your intake manifold, where it can sense full vacuum.

Every time the defective valve tries to close, the needle on the gauge will drop sharply.

A leaking head gasket is the easiest one to diagnose - if there is a leak you will be able to hear a strong whistle, or gas release every time the engine fires - parang 'air brake' yung tunog.

Just to be thorough check the spark plug of the 'dead' cylinder again - is there any sign of combustion residue or carbon on it - if YES then it's firing, so it must be getting gas.

Is it coated with oil - if YES then it's quite likely your piston rings are blown.

If it is clean and not covered in carbon or residue - then you may have a defective injector.

Hope this helps.

Best Regards,

Dusky Lim

Just the info i needed. hehehe

my girlfriend has and altima with an SR20 engine. 1 cylinder in not firing. mechanics in the fairview area says it requires a top overhaul. i dont believe them so i tested the compression and got the reading myself. all cylinders are in the 140-150 psi range. so i think okay ang engine. I also checked if there is a spark, okay naman.

i think its the injectors or the throttle body. any idea/recommended shop that can clean the injectors and/or throttle body? how much does this usually cost?

[duskylim]

Just the info i needed. hehehe

my girlfriend has and altima with an SR20 engine. 1 cylinder in not firing. mechanics in the fairview area says it requires a top overhaul. i dont believe them so i tested the compression and got the reading myself. all cylinders are in the 140-150 psi range. so i think okay ang engine. I also checked if there is a spark, okay naman.

i think its the injectors or the throttle body. any idea/recommended shop that can clean the injectors and/or throttle body? how much does this usually cost?

Hmmm.... Life is easy when you can use the expertise and experience of others for free, isn't it?

Expecting gratitude from those you help is asking too much.

[kitikiti]

Sir:

I you suspect a dead cylinder (for whatever reasons), then the simplest possible confirmation is a compression test.

Have this done by a competent shop and you should be able to see the readings for yourself.

Note them down and compare them.

If as you say, there is one dead cylinder, then the compression reading for that cylinder will be very much lower than the others.

As a rule of thumb, an engine is considered UNTUNEABLE if there is a 10% or greater difference in the compression reading between the cylinders.

A good shop should also be able to tell you the standard compression pressure of your engine.

Now, if the news is BAD - that you actually do have a dead cylinder - the next step is to determine whether it is a valve or piston ring problem.

If it is a piston ring problem it will be accompanied by BLOWBY - that's gases leaking past the piston rings into the crankcase.

Blowby will cause the pressure in the crankcase to build up, and the excess pressure will usually carry with it a lot of oil vapor - which tends to come out of the dipstick hole and the top of the valve cover assembly (the BREATHER).

You will be able to see, smell and almost taste this oil vapor when the engine is running - it will come out of those places I mentioned.

If there is LOW COMPRESSION but NO BLOWBY, then it is rather unlikely you have blown piston rings.

The obvious candidate then is leaky valves.

Another good test to perform AFTER the compression test is a vacuum gauge test.

Attach a sensitive and good-quality vacuum gauge to your intake manifold, where it can sense full vacuum.

Every time the defective valve tries to close, the needle on the gauge will drop sharply.

A leaking head gasket is the easiest one to diagnose - if there is a leak you will be able to hear a strong whistle, or gas release every time the engine fires - parang 'air brake' yung tunog.

Just to be thorough check the spark plug of the 'dead' cylinder again - is there any sign of combustion residue or carbon on it - if YES then it's firing, so it must be getting gas.

Is it coated with oil - if YES then it's quite likely your piston rings are blown.

If it is clean and not covered in carbon or residue - then you may have a defective injector.

Hope this helps.

Best Regards,

Dusky Lim

sorry to hijack this thread but you seem to know your stuff. i just have some querry which i hope you can shed light.

car is altis 1.6 matic vvti engine (old altis body). main issue is 2 and 4 do not fire or spark. just a brief history, at first, yung 1 ang walang spark. may fuel residue pa nga sa spark plugs. so sabi ng mechanic buksan cylinder head then pa align yung barbula then linisin piston rings. after this, prob got worse. yung 1 na ayos pero this time 2 and 4 walang spark. may power coming out on all 4 injectors. ecu works on another altis. yung socket para sa coil may power yung 4. na isolate na rin yung igniter at lahat ok naman. pag ilalagay yung igniter sa sokcet kung saan yung coil then i test with a spark plug, walang spark. di nya ma start yung engine. any idea will help. thanks.

[speed unlimited]

Sirkosero , Ang pag test ng injector kung hindi gumagana ay habang umaadar hugutin mo iyong plug na nakakabit sa injector pag hindi pumapalag makina ibig sabihin sira na ito . Ang surplus na injector para sa SR20 sa Banawe ay 800.00 /each . Ang brand new sa Nisman o Young bros . by order pa at walang stock.

[kompressor]

Just the info i needed. hehehe

my girlfriend has and altima with an SR20 engine. 1 cylinder in not firing. mechanics in the fairview area says it requires a top overhaul. i dont believe them so i tested the compression and got the reading myself. all cylinders are in the 140-150 psi range. so i think okay ang engine. I also checked if there is a spark, okay naman.

i think its the injectors or the throttle body. any idea/recommended shop that can clean the injectors and/or throttle body? how much does this usually cost?

Sir:

I you suspect a dead cylinder (for whatever reasons), then the simplest possible confirmation is a compression test.

Have this done by a competent shop and you should be able to see the readings for yourself.

Note them down and compare them.

If as you say, there is one dead cylinder, then the compression reading for that cylinder will be very much lower than the others.

As a rule of thumb, an engine is considered UNTUNEABLE if there is a 10% or greater difference in the compression reading between the cylinders.

A good shop should also be able to tell you the standard compression pressure of your engine.

Now, if the news is BAD - that you actually do have a dead cylinder - the next step is to determine whether it is a valve or piston ring problem.

If it is a piston ring problem it will be accompanied by BLOWBY - that's gases leaking past the piston rings into the crankcase.

Blowby will cause the pressure in the crankcase to build up, and the excess pressure will usually carry with it a lot of oil vapor - which tends to come out of the dipstick hole and the top of the valve cover assembly (the BREATHER).

You will be able to see, smell and almost taste this oil vapor when the engine is running - it will come out of those places I mentioned.

If there is LOW COMPRESSION but NO BLOWBY, then it is rather unlikely you have blown piston rings.

The obvious candidate then is leaky valves.

Another good test to perform AFTER the compression test is a vacuum gauge test.

Attach a sensitive and good-quality vacuum gauge to your intake manifold, where it can sense full vacuum.

Every time the defective valve tries to close, the needle on the gauge will drop sharply.

A leaking head gasket is the easiest one to diagnose - if there is a leak you will be able to hear a strong whistle, or gas release every time the engine fires - parang 'air brake' yung tunog.

Just to be thorough check the spark plug of the 'dead' cylinder again - is there any sign of combustion residue or carbon on it - if YES then it's firing, so it must be getting gas.

Is it coated with oil - if YES then it's quite likely your piston rings are blown.

If it is clean and not covered in carbon or residue - then you may have a defective injector.

Hope this helps.

Best Regards,

Dusky Lim

Malamang boss sa injector kasi kung throttle body ang problem, dapat problemado rin yung remaining 3 unless that has a different manifold with 4 throttle bodies (just like those manifolds with 4 individual solex carburetors back in the old days).

Try mo pagpalitin yung injectors itself. Pag pumalya yung pinaglipatan mo then the injector itself is the problem. Pwedeng electric solenoid or pwedeng barado lang. Try exhausting all means muna para buhayin yun. Cleaning, electrical, etc... Worst case scenario is to buy an injector itself and it ain't cheap.

Another is to remove the fuel rail together with the injectors, ground each injector body sa engine then crank the engine (medyo mabusisi and you have to have a good battery). A visual inspection will confirm kung merong injector na hindi sumisirit ng gasoline. Very important na no open flames nearby. He he he!



Another thing to note is you mentioned kamo na pareho silang lahat na may clicking sound so malamang pumapalo pa rin yung injector solenoid. Hypothesis ko diyan eh may bara lang. Babad mo sa kerosene yung tip then check mo kung kaya mo kalasin yung pinaka-solenoid. Baka kaya iba ang voltage reading is may resistance sa solenoid mismo?

[sirkosero]

Sirkosero , Ang pag test ng injector kung hindi gumagana ay habang umaadar hugutin mo iyong plug na nakakabit sa injector pag hindi pumapalag makina ibig sabihin sira na ito . Ang surplus na injector para sa SR20 sa Banawe ay 800.00 /each . Ang brand new sa Nisman o Young bros . by order pa at walang stock.

Malamang boss sa injector kasi kung throttle body ang problem, dapat problemado rin yung remaining 3 unless that has a different manifold with 4 throttle bodies (just like those manifolds with 4 individual solex carburetors back in the old days).

Try mo pagpalitin yung injectors itself. Pag pumalya yung pinaglipatan mo then the injector itself is the problem. Pwedeng electric solenoid or pwedeng barado lang. Try exhausting all means muna para buhayin yun. Cleaning, electrical, etc... Worst case scenario is to buy an injector itself and it ain't cheap.

Another is to remove the fuel rail together with the injectors, ground each injector body sa engine then crank the engine (medyo mabusisi and you have to have a good battery). A visual inspection will confirm kung merong injector na hindi sumisirit ng gasoline. Very important na no open flames nearby. He he he!



Another thing to note is you mentioned kamo na pareho silang lahat na may clicking sound so malamang pumapalo pa rin yung injector solenoid. Hypothesis ko diyan eh may bara lang. Babad mo sa kerosene yung tip then check mo kung kaya mo kalasin yung pinaka-solenoid. Baka kaya iba ang voltage reading is may resistance sa solenoid mismo?

Thanks for the tip and advise Kompressor and speed unlimited!

Thank you too dusky lim.

I went with my fuel injector hypothesis and researched on the internet and got a DIY guide for changing injectors of SR20. binili ko sa evangelista yung injector 800 pesos nga. and observed pano hugutin sa fuel rail. took out the injectors on the altima myself and replaced with the surplus 1 and okay na. car is running again. i used the budget para sa top overhaul para sa much needed suspension repairs hehehe.

DIY is so rewarding lalo na kung aandar ang ginawa mo hehehe