How do I adjust Idle RPM on CNG: Sensitivity Screw needs frequent adjustment

[talhawaleed]

I wanted to discuss this query with everyone, idle rpm of my corolla 13 creates a lots of problem on CNG. With every refill, idle RPM is different and needs to be adjusted through sensitivity screw otherwise RPM falls till 500 to 600 range and Engine stops.

In corolla 07 and Honda city, I have re-adjusted the idle RPM on CNG by changing the idle control sensors position on throttle body but configuration of corolla 13 GLi is different.

Car turns off on every stop, I have to keep a slight paddle on RPM and have to get it adjusted again from sensitivity screw(mostly people know this screw as idle RPM screw).

I have further discussed this with a CNG mechanic, he says that he will need to open the CNG kit in-order to remove the oil. CNG kit on this vehicle is already new and I know it won?t solve the problem. Further, he says that he cannot adjust the range of idle rpm further after opening it which I inquired from him.

Somebody body me about lambda control unit that after installation it will solve the problem, will it. Secondly one wire from the CNG advancer takes input from throttle position sensor which in some case is routed back through advancer into ECU. Would changing to this configuration will help, does cng advancer also controls the idle rpm after taking the input from throttle position sensor. I know that in MAF sensor, it manipulates its values on cng and provide completely different to the ECU.

I have tried many versions of TL advancer emulator but problem is still same.

[hash4u]

i have 2 air cleaners. the better fine built one(much more porous)---my car hardly iddles on it
a second air filter "namda" type, which kind of blocks air compared to the finner filters.car iddles just fine on that

changing air filter takes 20 seconds in city idsi

[supraman2jz]

That's is exactly what I've noticed. I was using a Leppon air filter in my Civic EG and the car idled fine on CNG. The day I had an oil change along with the usual oil filter and air cleaner change, the car refused to idle fine and now I have to constantly adjust the idle screw. I don't remember the brand of air filter that I've bought but it must be better than Leppon.

Before the Leppon filter, I bought a cheap 200 Rs filter and the idle was even better and the car had pretty good torque off the line.

[fawadakbarkhan]

i have 2 air cleaners. the better fine built one(much more porous)---my car hardly iddles on it
a second air filter "namda" type, which kind of blocks air compared to the finner filters.car iddles just fine on that

changing air filter takes 20 seconds in city idsi

Why do you keep both?

[hash4u]

^^
yaar itni lambi story likhi to hi

1 filter for cng
1 filter when cng finishes and have to drive on petrol

good quality filters let to much air in for cng making mixture lean

cng tunners put tapes and what not to block air.i dont like that

[fawadakbarkhan]

^^
yaar itni lambi story likhi to hi

1 filter for cng
1 filter when cng finishes and have to drive on petrol

good quality filters let to much air in for cng making mixture lean

cng tunners put tapes and what not to block air.i dont like that

LOL acha acha. aap ne ye baat nae likhi bhae. CNG aur petrol k liay wakhra wakhra filter.

I will do the same now. Can you mention the brands?

[talhawaleed]

Having different filters for CNG and petrol seems very unpractical as I drive my cars on both fuels. I will try if blocking the air intake solves the problem or not, for which I was against but never thought that poor idling might be because of it . Has anyone tried lambda unit.

[supraman2jz]

Your car will start knocking on petrol if you add blockage.

[hash4u]

LOL acha acha. aap ne ye baat nae likhi bhae. CNG aur petrol k liay wakhra wakhra filter.

I will do the same now. Can you mention the brands?

guard or leppon is good for petrol
unmarked desi filter is fine for cng

Lambda sucks
u can take the lambda from me for free.i took it off.replaced the power T twice.few people get sick of lambdas in efi cultus company fitted cng even and take it off

[MarX]

@OP
block the air filter pipe by making a venturi
your problem will be solved
My 07 Gli used to burn the filters every now and then.
and I was able to immediately recognize a burned filter by
fluctuations of RPM .

[xenerking]

guard or leppon is good for petrol
unmarked desi filter is fine for cng

Lambda sucks
u can take the lambda from me for free.i took it off.replaced the power T twice.few people get sick of lambdas in efi cultus company fitted cng even and take it off

that LAMBDA is mine....please let me know how to retrieve it from you

[argtr65]

Air blockage and change of air filter will not help you in this situation,it is all happening because of cng contaminated with oil now-a-days due to over exertion of compressors because of frequent gas load shedding,remove oil drain plug from cng regulator and put it back after oil draining.

[talhawaleed]

Air blockage and change of air filter will not help you in this situation,it is all happening because of cng contaminated with oil now-a-days due to over exertion of compressors because of frequent gas load shedding,remove oil drain plug from cng regulator and put it back after oil draining.

no it has been happening from day one, since i installed a new kit. car only has 12500km on clock.

[hash4u]

ok let me dig the lambda unit from the store room
all u will need to add is a stepper motor in it

[talhawaleed]

ok let me dig the lambda unit from the store room
all u will need to add is a stepper motor in it

I am surprised at your comments on lambda unit, but will definitely would like to try that and seems like, I will have to get in touch with you.
Brother, if you have a second hand lying with you then please quote me a price in private message.

[xenerking]

ok let me dig the lambda unit from the store room
all u will need to add is a stepper motor in it

thank u

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