[justadiz]

Originally Posted by Mr.Boss

Nope.
I have hands on experience with LPG for over 2 decades but not with CNG.

Is LPG/Auto-gas still popular up north?, here in South, Ive noticed the number of stations go down?

[TB16]

Originally Posted by justadiz

Have any other gentlemen who have CNGed their Santro or similar MPFI Engine cars, what are your experiences?

I had a 2004 Santro Xing XS which i sold in 2014. I had installed a conventional kit only in 2009 and used the car for 50k km appox purely on CNG. Apart from tuning every 10-15k km, everything was normal. So i think you can go with the normal kit and save the rest for future use on the car.

[justadiz]

Originally Posted by TB16

I had a 2004 Santro Xing XS which i sold in 2014. I had installed a conventional kit only in 2009 and used the car for 50k km appox purely on CNG. Apart from tuning every 10-15k km, everything was normal. So i think you can go with the normal kit and save the rest for future use on the car.

Wow, I heard someone here saying Normal kits(Open Loop) ruin the engine's head over time.

Yours was an open loop system, right?

[TB16]

Yes, the loop conventional kit only (not sequential). Infact after enjoying CNG on my Santro, i installed the same type of conventional kit in my 2005 Honda City ZX VTEC. That also ran smoothly for 50k-60k km purely on CNG before it met with an accident and was declared total loss by insurance. Otherwise i would've continued with it for atleast 100k km.

I think it all depends on your installer. If he knows what he is doing, its a very simple plug and play and tuning.

[justadiz]

Originally Posted by TB16

Yes, the loop conventional kit only (not sequential). Infact after enjoying CNG on my Santro, i installed the same type of conventional kit in my 2005 Honda City ZX VTEC. That also ran smoothly for 50k-60k km purely on CNG before it met with an accident and was declared total loss by insurance. Otherwise i would've continued with it for atleast 100k km.

I think it all depends on your installer. If he knows what he is doing, its a very simple plug and play and tuning.

I see, well i went to a local CNG Retrofitting shop, they quoted 40.5k for a Lovato Conventional CNG Kit, complete with advancer and they will do the RC endorsal for you, however, one thing itches at the back of my mind.
On the internet, ive seen the engine bay of multiple santros with the conventional kit installed, now Santro's IAC valve is independent from its throttle body, with it being situated at the end of the intake manifold with a direct pipe to the air filter box, some install configuration shows a pipe from the mixer(not the big pipe delivering gas from the reducer) connected to the intake pipe of the IAC, whereas some installs don't have this sort of connection and just has the mixer connected to the throttle body .
The guy at my center swears that it has always worked without needing this extra connection from the mixer to IAC, it baffles me, how does the engine get the gas to combust during idling if the throttle body is closed and with no cng connection to the IAC?

What sort of setup did your Santro use, if you dont mind me asking.

[TB16]

Originally Posted by justadiz

What sort of setup did your Santro use, if you dont mind me asking.

I've absolutely no idea about the technical details of the conventional CNG kit installed in my Santro. I believe all cars before obd2 era can only be installed with convention kits. Visit more installers if you're having doubts. But 40k for a normal kit is steep. Here in Delhi, a conventional setup wont cost more than 30k including RC.

[justadiz]

Originally Posted by TB16

I've absolutely no idea about the technical details of the conventional CNG kit installed in my Santro. I believe all cars before obd2 era can only be installed with convention kits. Visit more installers if you're having doubts. But 40k for a normal kit is steep. Here in Delhi, a conventional setup wont cost more than 30k including RC.

i see, well CNG only started popping up around here a couple of years back, just when petrol prices started to go to a cut throat level, in fact, 40 was the lowest quote i got, ever other installer is demanding 45+ for a conventional system, at the same time, an installer in Delhi offered to fit a sequential kit for 38k(RC included). Either way, im visiting the installer this Saturday, if i do end up fitting, ill make sure to update here

At the moment, CNG costs 88/kg and Petrol costs 109.62/Litre

[TB16]

Originally Posted by justadiz

At the moment, CNG costs 88/kg and Petrol costs 109.62/Litre

CNG will be beneficial even if the prices become same in the future IMO. This is because the average is almost double that of petrol. So if your average daily running is more than 35-40 Kms and planning to hold the vehicle for minimum 3-4 years, CNG will be a good idea.

[justadiz]

Originally Posted by TB16

CNG will be beneficial even if the prices become same in the future IMO. This is because the average is almost double that of petrol. So if your average daily running is more than 35-40 Kms and planning to hold the vehicle for minimum 3-4 years, CNG will be a good idea.

Finally gave in and retrofitted my Santro Xing with a Lovato Conventional Kit, i went in on Saturday morning, the kit was fitted by the end of the day, and after test driving , i was handed the car back.

And less than 1km after getting it back, the car started acting up, The ride in petrol is really really jerky, and the engine wont idle properly in Petrol and dies quickly, before the
CNG could kick in.The next day was sunday, so i was left without a ride.

Today, the CNG technicians came to our house, and changed the Emulator, yet the problem still existed, they dismantled everything, and the issue was finally solved with the help of an OBD Scanner, the CNG guys connected it to my car, did something and the petrol problem disappeared, but it came back soon after running in CNG.

Now, i can drive the car, the CNG guys told me to pump the accelerator while starting to enable it to rev and switch to gas.

Sometimes, it dosent start after one crank and needs multiple cranks to start.

Does anyone know how to fix it? the CNG guys are saying its the Petrol ECU adapting to the CNG and the problem will disappear over time.

[TB16]

Originally Posted by justadiz

Does anyone know how to fix it? the CNG guys are saying its the Petrol ECU adapting to the CNG and the problem will disappear over time.

This should not happen if they have done the conversion & tuning properly. Ideally the car will run same as petrol but with 10-15% less power. No vibrations or harshness as such.

[justadiz]

Originally Posted by TB16

This should not happen if they have done the conversion & tuning properly. Ideally the car will run same as petrol but with 10-15% less power. No vibrations or harshness as such.

Oh, it got much worse, its takes really long to start on CNG, sometimes, it dosent switchover successfully to cng, causing the engine to stall, on Petrol, the ride is really really jerky and stalls if you dont rev the living daylights out of it.

And my heart sank when i did a mileage test and i got 10km per kg (city with AC).

So, i have successfully ruined my working petrol car, got low power, became unreliable and still got the same fuel economy as petrol

[TB16]

Originally Posted by justadiz

Oh, it got much worse, its takes really long to start on CNG, sometimes, it dosent switchover successfully to cng

Car should start on petrol, not CNG. After 2-3 km or when optimum temperature is reached, it should automatically switch to CNG.

I think this a classic case of wrong fitment or bad tuning. Try showing it to a different installer and get it rectified. CNG fitment is no rocket science. Can be resolved easily.

[justadiz]

Originally Posted by TB16

Car should start on petrol, not CNG. After 2-3 km or when optimum temperature is reached, it should automatically switch to CNG.

I think this a classic case of wrong fitment or bad tuning. Try showing it to a different installer and get it rectified. CNG fitment is no rocket science. Can be resolved easily.

Car starts on petrol as its supposed to, but it takes really long to start and misfires like crazy, with the help and assistance of a kind bhpian here, i was able to diagnose it as cng mixing with petrol while in petrol mode, setting off the sensors and causing issues, because the car runs fine on petrol after an ECU reset, so, the current diagnosis is a faulty reducer, im running my car on petrol currently since i have some trips to make and need the car to be reliable. Ill be taking my car to the fitment center to get it checked out.

Did your Santro run fine in both Petrol mode and CNG mode?

Also, i noticed something else, on Petrol mode(even before CNG conversion), the engine sounded throaty and raspy, and it didnt tolerate chugging around at high gear at low speeds. But the entire character of the engine changes on CNG mode, its really quiet, quiet enough for me that i sometimes forget to upshift to 5th because i sort of used the engine sound as a reference point to shift gear. And i can drive around perfectly on 5th gear at speeds as low as 25km/hour. Gear shift are also smoother on CNG.

[TB16]

Originally Posted by justadiz

Did your Santro run fine in both Petrol mode and CNG mode?

Yes, absolutely fine on both petrol on CNG. Reducer is the main part of a CNG kit. Get it changed and then enjoy the drive.

Since CNG is a slow burning fuel than petrol, that raspiness growl in the engine will be lost. So that is something you'll have to live with. What you'll get is extreme efficiency (25+ km/kg).

[justadiz]

Originally Posted by TB16

Yes, absolutely fine on both petrol on CNG. Reducer is the main part of a CNG kit. Get it changed and then enjoy the drive.

Since CNG is a slow burning fuel than petrol, that raspiness growl in the engine will be lost. So that is something you'll have to live with. What you'll get is extreme efficiency (25+ km/kg).

As for the lack of raspiness, im not really complaining, i loved it, sure pickup is bad, but the engine sounds much more calmer, and for some reason, the throttle (on CNG) is much more responsive(Which i assume is due mechanical venturi fuel delivery rather than electronic delivery of fuel).

As for the efficiency factor, i guess i will have to get it tuned, because currently, it gives 10km/kg(City with AC on always)

The car is old, by 12 years and 95,000km on the odometer. I wish to keep her for a couple of years(or until the 15 year re-registration)