[coolmob]

my santro is december 2004, with around 36000 Kms on the ODO. the car has CNG fitted in it.

my problem is that the engine is giving missing problem on both CNG and PETROL from some time. especially when the car is idling the car vibrates like anything because of the missing. but once i start driving it drives without any problem. its also giving me less fe compared to when there was no missing problem.


can anyone suggest how to diagnose and rectify the problem.

[1self]

Get your sparks, fuel filter, spark plug wires checked. See if you need a de-carb (depending on the quality of fuel). Better if an authorised Hyundai A.S.S. guy saw it.

[Sam Kapasi]

Oh so your engine is still inside your car?? I thought someone stole the engine block or something.

Sheesh you car guys.

[wolfinstein]

In the Order

1) Check the Plugs(When was the last time you changed it, cleaned it)
2) Ignition Coil ( Things can fail,cause missing issues)
3) Check/Clean/Replace Air Filter Element
4) Throttle Cleaning

If the above don't solve the problem , then :

5) Visit The Hyundai Service Station get the Timing checked up and Ignition Coil Voltage using the ECU Scanner, This will help isolate Ignition Coil issues and Timing.

6) Visit the CNG Installer and check the Condition of the Diaphragm & Plunger(Inside the Reducer Unit-Its not a DIY and neither everybody's expertise go to the CNG Installer or a good CNG Technician), After a certain time these things get dirty and need servicing.

But since the problem is on Both Petrol and CNG, Its most likely Dirty or Damaged Plugs + Air Filter, Throttle.

Try solving using the solution, the last option is Preventive and good after a certain time of Usage.

[1self]

Well written! How is the throttle responsible for this?

Originally Posted by wolfinstein

In the Order

1) Check the Plugs(When was the last time you changed it, cleaned it)
2) Ignition Coil ( Things can fail,cause missing issues)
3) Check/Clean/Replace Air Filter Element
4) Throttle Cleaning

If the above don't solve the problem , then :

5) Visit The Hyundai Service Station get the Timing checked up and Ignition Coil Voltage using the ECU Scanner, This will help isolate Ignition Coil issues and Timing.

6) Visit the CNG Installer and check the Condition of the Diaphragm & Plunger(Inside the Reducer Unit-Its not a DIY and neither everybody's expertise go to the CNG Installer or a good CNG Technician), After a certain time these things get dirty and need servicing.

But since the problem is on Both Petrol and CNG, Its most likely Dirty or Damaged Plugs + Air Filter, Throttle.

Try solving using the solution, the last option is Preventive and good after a certain time of Usage.

[wolfinstein]

The throttle, after a certain period of time accumalates dust and gum deposits, since it takes in the Air coming from the Air filter Element,which still passes dust that sticks on to the Throttle body and Manifold- This causes variation in the throttle Positioning sensor and Idle Speed sensor module which gives inaccurate reading,vibrations and low pickup.

Depends on the conditions the car is being driven, for CNG Vehicles the CNG:AIR ratio needs to be lean and since it passes through the throttle,advisory range for cleaning is every 10,000 Km but sooner if such problems are faced.

[DieselFan]

It might also be an ECU problem. take it to the nearest A.S.S. and get the issue diagnosed. Please do not suggest any solution to them but get the problem first identified and then they will fix it.