Need Advise of Experts on Mileage Issue with Suzuki Margallah

[Thinking]

@faisalkaram

Bro dont worry.

Be assured that margallah is probably the best machine to run on CNG.

As suggested by Imran above please follow a systematic method to trouble shoot and fix the issue

1) Valve timing
2) Ignition timing
3) Ignition timing advance mechanism functional operation. (Use timing gun)
4) Ensure that a thermostatic valve has been installed in the cooling system
5) Radiator fan is operated on auto.
6) To check if the car is tuned or not properly please check the plugs, ideally they should be redish brown once taken out.
7) easiest way to get timing and plugs checked and fuel mixture adjusted is to go to a Enercon centre. Its a project run by Government Ministry of Environment and they tune the car to ensure minimal exhaust gases which in turn ensures proper fuel milage. i have seen there outlets at multiple places in ISB and i think in LHR too. please check their web site and it should help you.

[margallar]

7.5 km in a litre is definitely a carb tuning problem or some problem with the carburetor itself

[Thinking]

as far as i know there is no specific calibaration of margallah aisin carb. its fixed and tuned. however fuel of the car can be set depending upon the air flow from a screw at the back of the carb underneath ail filter housing.

[imransaleemss]

as far as i know there is no specific calibaration of margallah aisin carb. its fixed and tuned. however fuel of the car can be set depending upon the air flow from a screw at the back of the carb underneath ail filter housing.

If the mechanic was good tuned the carb then must be in one litre main 12-14km kerni chahiay or just change the butterflay of the carburator then its give you good mialage

[imrananr]

as far as i know there is no specific calibaration of margallah aisin carb. its fixed and tuned. however fuel of the car can be set depending upon the air flow from a screw at the back of the carb underneath ail filter housing.

The carburettor needs disassembly and cleaning. Their are tinny passages, jets responsible for proper air/fuel ratio at different throttle positions, instant acceleration, idle etc. A specialist involved in carb. service knows which passages clog and effect what. On top of this, proper float adjustment plays a vital role in air/fuel ratio. It's the heart of the fuel system.

[imrananr]

as far as i know there is no specific calibaration of margallah aisin carb. its fixed and tuned. however fuel of the car can be set depending upon the air flow from a screw at the back of the carb underneath ail filter housing.

The screw you are talking about is responsible for adjusting air/ fuel ratio only at idle position. But again, clogged passages inside the carburettor body and jets are responsible for poor fuel economy.

[margallar]

The screw you are talking about is responsible for adjusting air/ fuel ratio only at idle position. But again, clogged passages inside the carburettor body and jets are responsible for poor fuel economy.

i meant to say that afr might not be correct

[faisalkarim55]

thanks alot guys... will let you know the proceedings

[faisalkarim55]

i think all the replies to my query are not showing on the forum topic. I read them in the email. So answering here.

I have got my carburetor serviced from a well known carb. expert (mehmood engineering works - near mama parsi school). He serviced the carburetor and repaired the butterfly. So, i suppose carburetor is not the problem any more. As for oil thing, I have no idea what my father has been using. Please suggest one that suits margalla with CNG. About the spark plugs thing, i think spark plugs should be the reason if car continues to stop while driving slow and with brake application. The car works fine (i mean no jerks once it is hot - after running a couple of kms). There are two main issues right now

Jerks till the car is hot (both petrol and CNG)
Stoppages till hot (only CNG)
Fuel consumption on petrol (insane - 7 to 7.5 km/ltr)

going to check the list provided by Imran and thinking.... will share the results

[faisalkarim55]

on 15-oct-2014, got ignition timing correction and spark plugs checking and cleaning. The car is flying in the air but havent checked the mileage yet as it takes time to determine correct mileage. Here I would like to ask the experts about correct mileage determination technique. WHATS THE BEST WAY TO CHECK MILEAGE?
1- Fill 10 litre petrol in empty tank. Drive till last drop and check mileage?
2- Get Tank Full, drive 100 km, refill to full tank and check how much litres were required for full tank and divide the mileage with litres filled?

suggestions plz
PS: my mechanic suggested No. 2

[imrananr]

on 15-oct-2014, got ignition timing correction and spark plugs checking and cleaning. The car is flying in the air but havent checked the mileage yet as it takes time to determine correct mileage. Here I would like to ask the experts about correct mileage determination technique. WHATS THE BEST WAY TO CHECK MILEAGE?
1- Fill 10 litre petrol in empty tank. Drive till last drop and check mileage?
2- Get Tank Full, drive 100 km, refill to full tank and check how much litres were required for full tank and divide the mileage with litres filled?

suggestions plz
PS: my mechanic suggested No. 2

Both methods are ok. The first one may give you more accurate results. But, what milage you are checking? Is it urban or combined.
Combined means on highway and urban combined. Then there is urban and extra urban. I mean encountering traffic jams etc.

[imrananr]

on 15-oct-2014, got ignition timing correction and spark plugs checking and cleaning. The car is flying in the air but havent checked the mileage yet as it takes time to determine correct mileage. Here I would like to ask the experts about correct mileage determination technique. WHATS THE BEST WAY TO CHECK MILEAGE?
1- Fill 10 litre petrol in empty tank. Drive till last drop and check mileage?
2- Get Tank Full, drive 100 km, refill to full tank and check how much litres were required for full tank and divide the mileage with litres filled?

suggestions plz
PS: my mechanic suggested No. 2

With step 1, check the milage when engine stalls...

[Thinking]

I would suggest to fill the tank to the level where you can see the fuel in the filling hose.

Drive the car to 100 KM and again fill the tank (from the same pump preferably at the same time) to the same level where you can again see the fuel in filling hose.

divide # of KMs traveled by the amount of fuel that went in. should give you correct milage.

[Thinking]

If car is running on GAS, advance the ignition timing to 15 degrees.

[Thinking]

Dear Fellows,

now i can report improvement in the milage with verification.

the culprit was a faulty AC pulley bearing which was only identified when it started making noise. Replaced a NACHI bearing with KOYO.

Improved the milage. 2ndly i also got the return pipe to fuel tank functionality verified and got it cleaned, there was a suspicion of malfunction and cloggin in that pipe too.

[Thinking]

since end of the month is approachin i might not be able to brim the fuel tank. will share the exact improved milage figures in next month.

[faisalkarim55]

how to advance ignition timing? can I do it myself?

[margallar]

Dear Fellows,

now i can report improvement in the milage with verification.

the culprit was a faulty AC pulley bearing which was only identified when it started making noise. Replaced a NACHI bearing with KOYO.

Improved the milage. 2ndly i also got the return pipe to fuel tank functionality verified and got it cleaned, there was a suspicion of malfunction and cloggin in that pipe too.

what was the cost, i think i should replace all of the bearings on my engine too

[Thinking]

Cost details are mentioned below

1-koyo bearing 160 Rs
2-AC Pulley belt 200 Rs
3- Labour 140 Rs

Total : 500 Rs

I wouldn't suggest replacing all bearing for no good reason. My mechanic has a stethoscope screw driver. he placed it on the faulty pulley about which i was complaining (coz it stopped making noise once i reached workshop) however the voice of the bearing got enhanced when we put our ear near the other end of screw driver.

Verified other bearings with similar process.

cost of bearings vary with their size. usually Koyo and Nachi bearing are orignal japanese and work well.

[imrananr]

Cost details are mentioned below

1-koyo bearing 160 Rs
2-AC Pulley belt 200 Rs
3- Labour 140 Rs

Total : 500 Rs

I wouldn't suggest replacing all bearing for no good reason. My mechanic has a stethoscope screw driver. he placed it on the faulty pulley about which i was complaining (coz it stopped making noise once i reached workshop) however the voice of the bearing got enhanced when we put our ear near the other end of screw driver.

Verified other bearings with similar process.

cost of bearings vary with their size. usually Koyo and Nachi bearing are orignal japanese and work well.

I far as I know, the best reputed bearing manufacturing companies are SKF, NTN, *** and NSK.