Air Flow Sensor Problem...!!!

[Rox]

My father drives a Mitsubishi Libero station vagon which has an EFI engine of 1300 cylinder capacity. Engine power and acceleration of the engine was very good for a 2-3 years since he bought it and it has just completed its 100,000 km now.

However, nearly a one year before, when he was driving from Kandy to Colombo a very bad miss in the engine took place at around 110 km and he had to stop the car and after about 30 mins he was be able to drive again but for only about 5 km and again the engine miss was there. But the next morning the car was ok and could drive another 110 km and then the miss comes again. (Seems the problem takes place when the engine is becoming hotter...)

So, my father took the car to MAG CITY for an engine scan and their decision was that the AIR FLOW SENSOR is out of order and it should be replaced. According to them, this is the thing which was connected some distance below exhaust outlet. The item was not available in Sri Lanka and agents (########) demanded Rs. 98,000/- to import it from Japan. We gave up that option then and tried to fix the problem with many mechanics but the problem is still there. Also, I should say that, now there is a small miss even when we just start the engine and acceleration is not good as before.

Some ideas of several mechanics was;

1. Yes, Problem is in AIR FLOW SENSOR, Replace it...!!!

2. Yes, Problem is in AIR FLOW SENSOR, Can fix it (But we couldn't find anyone who could do it...!!!)

3. No, the problem is in DISTRIBUTOR (or DALCO we call it, isn't it?), Replace it (But, no one was brave enough to replace it and test.... )

4. No, the problem is in Catalytic Converter, the ceramic mesh inside should be cleaned or removed..... (This actually we can do, but I'm waiting for an expert to comment..)

Experts, what is your idea about this issue according to above symptoms??? Please help.......

[Nilantha]

if the agents said that air flow sencer defective you have to relapse it. if you can give me correct part number i will try to find a price.

[Ruslan]

My father drives a Mitsubishi Libero station vagon which has an EFI engine of 1300 cylinder capacity. Engine power and acceleration of the engine was very good for a 2-3 years since he bought it and it has just completed its 100,000 km now.

However, nearly a one year before, when he was driving from Kandy to Colombo a very bad miss in the engine took place at around 110 km and he had to stop the car and after about 30 mins he was be able to drive again but for only about 5 km and again the engine miss was there. But the next morning the car was ok and could drive another 110 km and then the miss comes again. (Seems the problem takes place when the engine is becoming hotter...)

So, my father took the car to MAG CITY for an engine scan and their decision was that the AIR FLOW SENSOR is out of order and it should be replaced. According to them, this is the thing which was connected some distance below exhaust outlet. The item was not available in Sri Lanka and agents (########) demanded Rs. 98,000/- to import it from Japan. We gave up that option then and tried to fix the problem with many mechanics but the problem is still there. Also, I should say that, now there is a small miss even when we just start the engine and acceleration is not good as before.

Some ideas of several mechanics was;

1. Yes, Problem is in AIR FLOW SENSOR, Replace it...!!!

2. Yes, Problem is in AIR FLOW SENSOR, Can fix it (But we couldn't find anyone who could do it...!!!)

3. No, the problem is in DISTRIBUTOR (or DALCO we call it, isn't it?), Replace it (But, no one was brave enough to replace it and test.... )

4. No, the problem is in Catalytic Converter, the ceramic mesh inside should be cleaned or removed..... (This actually we can do, but I'm waiting for an expert to comment..)

Experts, what is your idea about this issue according to above symptoms??? Please help.......

well if the problem with the MAF (Mass Air Flow Sensor) then you better replace it. never heard anyone could repair it so far. why dont you try to find a recon MAF sensor! would be cheaper than those figures..

Edited January 7, 2009 by Ruslan

[Supra_Natural]

My father drives a Mitsubishi Libero station vagon which has an EFI engine of 1300 cylinder capacity. Engine power and acceleration of the engine was very good for a 2-3 years since he bought it and it has just completed its 100,000 km now.

However, nearly a one year before, when he was driving from Kandy to Colombo a very bad miss in the engine took place at around 110 km and he had to stop the car and after about 30 mins he was be able to drive again but for only about 5 km and again the engine miss was there. But the next morning the car was ok and could drive another 110 km and then the miss comes again. (Seems the problem takes place when the engine is becoming hotter...)

So, my father took the car to MAG CITY for an engine scan and their decision was that the AIR FLOW SENSOR is out of order and it should be replaced. According to them, this is the thing which was connected some distance below exhaust outlet. The item was not available in Sri Lanka and agents (########) demanded Rs. 98,000/- to import it from Japan. We gave up that option then and tried to fix the problem with many mechanics but the problem is still there. Also, I should say that, now there is a small miss even when we just start the engine and acceleration is not good as before.

Some ideas of several mechanics was;

1. Yes, Problem is in AIR FLOW SENSOR, Replace it...!!!

2. Yes, Problem is in AIR FLOW SENSOR, Can fix it (But we couldn't find anyone who could do it...!!!)

3. No, the problem is in DISTRIBUTOR (or DALCO we call it, isn't it?), Replace it (But, no one was brave enough to replace it and test.... )

4. No, the problem is in Catalytic Converter, the ceramic mesh inside should be cleaned or removed..... (This actually we can do, but I'm waiting for an expert to comment..)

Experts, what is your idea about this issue according to above symptoms??? Please help.......

If you search for MAG city on this site just a bit, you'll find that there is a general consensus that says the place isnt the greatest at getting things done, never been there myself but have had plenty of stories related that describe it as the sort of place one should avoid!

With regard to your MAF, have you had the agents take a look at the car? did they also diagnose the problem as the MAF? it might well be worth your while to have them take a look at it as well if you havent already..

as for the cost of the unit, you should definitely take a look at some other parts suppliers as well, because it's quite likely you can get a replacement for much cheaper. The Don will be able to advise you better on this...

[The Don]

My father drives a Mitsubishi Libero station vagon which has an EFI engine of 1300 cylinder capacity. Engine power and acceleration of the engine was very good for a 2-3 years since he bought it and it has just completed its 100,000 km now.

However, nearly a one year before, when he was driving from Kandy to Colombo a very bad miss in the engine took place at around 110 km and he had to stop the car and after about 30 mins he was be able to drive again but for only about 5 km and again the engine miss was there. But the next morning the car was ok and could drive another 110 km and then the miss comes again. (Seems the problem takes place when the engine is becoming hotter...)

So, my father took the car to MAG CITY for an engine scan and their decision was that the AIR FLOW SENSOR is out of order and it should be replaced. According to them, this is the thing which was connected some distance below exhaust outlet. The item was not available in Sri Lanka and agents (########) demanded Rs. 98,000/- to import it from Japan. We gave up that option then and tried to fix the problem with many mechanics but the problem is still there. Also, I should say that, now there is a small miss even when we just start the engine and acceleration is not good as before.

Some ideas of several mechanics was;

1. Yes, Problem is in AIR FLOW SENSOR, Replace it...!!!

2. Yes, Problem is in AIR FLOW SENSOR, Can fix it (But we couldn't find anyone who could do it...!!!)

3. No, the problem is in DISTRIBUTOR (or DALCO we call it, isn't it?), Replace it (But, no one was brave enough to replace it and test.... )

4. No, the problem is in Catalytic Converter, the ceramic mesh inside should be cleaned or removed..... (This actually we can do, but I'm waiting for an expert to comment..)

Experts, what is your idea about this issue according to above symptoms??? Please help.......

Hi,

From what you it sounds like the problem is electronic and it could very well be the air flow sensor. But you need to confirm this with somebody else and I suggest Macro Auto Tech Nawala who compared to MAG City is thousand times better.

MAG sent us on a wild Goose chase as well and it was Macro in the end who identified the root of the problem.

Once you've identified the problem there is an area called the Watte in Panchikawatte along the canal and this place is full of used engines. The chances are you'll be able to find the relevant sensor from one of the used engines. If the sensor is not available brand new at a reasonable this is the next best option. But please make sure that it is indeed the air flow sensor before proceeding further.

The Don

Edited January 7, 2009 by The Don

[charitha19]

yeah i think first go to the agents to see if its actually the air flow sensor...

accroding to ur symptoms i feel that even if it is the sensor its not fully gone yet..

[Rox]

if the agents said that air flow sencer defective you have to relapse it. if you can give me correct part number i will try to find a price.

Nilantha, thanx...... I will let you know it as soon as possible...... :-)

[Rox]

Hi,

From what you it sounds like the problem is electronic and it could very well be the air flow sensor. But you need to confirm this with somebody else and I suggest Macro Auto Tech Nawala who compared to MAG City is thousand times better.

MAG sent us on a wild Goose chase as well and it was Macro in the end who identified the root of the problem.

Once you've identified the problem there is an area called the Watte in Panchikawatte along the canal and this place is full of used engines. The chances are you'll be able to find the relevant sensor from one of the used engines. If the sensor is not available brand new at a reasonable this is the next best option. But please make sure that it is indeed the air flow sensor before proceeding further.

The Don

Thanx Don....

Yes, I also have heard that MAG City is not a good place but as the vehicle was in Kandy this was the only available place. Also I should mention that we did not took it to ######## for an engine scan.

However, we tried to find a recon part for this, which was unsuccessful as this vehicle seems uncommon in Sri Lanka.

[Ruslan]

Thanx Don....

Yes, I also have heard that MAG City is not a good place but as the vehicle was in Kandy this was the only available place. Also I should mention that we did not took it to ######## for an engine scan.

However, we tried to find a recon part for this, which was unsuccessful as this vehicle seems uncommon in Sri Lanka.

true that the vehicle is uncommon but the engine must be similar 1300CC engine that used in most of the Lancers which came in those years which your Wagon manufactured. so when you looking, make sure to look for the specific Engine model.

[Supra_Natural]

Thanx Don....

Yes, I also have heard that MAG City is not a good place but as the vehicle was in Kandy this was the only available place. Also I should mention that we did not took it to ######## for an engine scan.

However, we tried to find a recon part for this, which was unsuccessful as this vehicle seems uncommon in Sri Lanka.

the vehicle itself might be uncommon, but the engine in it is probably one that was available in other models in SL

Edit: okay this is weird, the specs for the libero dont make any mention of a 1.3 l engine

http://specs.amayama.com/mitsubishi/libero/

Rox, Post the engine number if possible

Edited January 7, 2009 by Supra_Natural

[The Don]

Thanx Don....

Yes, I also have heard that MAG City is not a good place but as the vehicle was in Kandy this was the only available place. Also I should mention that we did not took it to ######## for an engine scan.

However, we tried to find a recon part for this, which was unsuccessful as this vehicle seems uncommon in Sri Lanka.

There was only a finite number of Engines used in Mitsubishi vehicles. If you tell us the first bit of your engine number (don't post the whole number for security reasons) we would be able to advise you better as to how to look for a MAF. I think the MAF sensor is actually shared amongst most Mitsubishi vehicles. I know my car's MAF sensor is the same as the Evo for starters. Your engine should be a 4G13, as I don't remember any other commonly used 1300CC engine on Mitsubishi cars, and this is the most commonly used 1300cc engine and goes in everything. So finding parts should not be that difficult. (the first 4 symbols of your engine number indicate what engine type it is)

But the important thing is to make sure that is the issue. Problems with Oxygen sensors, the distributor cap, ignition system, vacuum system all manifest in engine misses and it is important to identify and verify what the problem actually is.

MAG diagnosed an issue with my ECU as a problem with the throttle body, costing us a new throttle body, sensors, labour 3 times over and finally a used ECU.

One needs to be very careful in these type of issues as Electronic Diagnostic systems do not always report the root cause of the problem, just symptoms.

My tech Wasantha should be able to help you source the MAF if all else fails, but he does not have electronic diagnostic equipment so you still need to go somewhere who has a good piece of kit plug it in and see for yourself what the report says. If the your ECU is reporting MAF failiure and nothing else then its likely to be the cause of the problem. But if it reports MAF failiure and other parameters are a bit iffy or if its reporting other issues as well it could be something else, like the ECU for example.

Also does the check engine light come on, which should if the MAF sensor is faulty.

The Don

[Rox]

the vehicle itself might be uncommon, but the engine in it is probably one that was available in other models in SL

Edit: okay this is weird, the specs for the libero dont make any mention of a 1.3 l engine

http://specs.amayama.com/mitsubishi/libero/

Rox, Post the engine number if possible

Thanx.....

Yes, it seems there is no model with 1.3 l engine. But according to my father it is 1.3 l, so I may have to have another look at it............ :-)

[Rox]

There was only a finite number of Engines used in Mitsubishi vehicles. If you tell us the first bit of your engine number (don't post the whole number for security reasons) we would be able to advise you better as to how to look for a MAF. I think the MAF sensor is actually shared amongst most Mitsubishi vehicles. I know my car's MAF sensor is the same as the Evo for starters. Your engine should be a 4G13, as I don't remember any other commonly used 1300CC engine on Mitsubishi cars, and this is the most commonly used 1300cc engine and goes in everything. So finding parts should not be that difficult. (the first 4 symbols of your engine number indicate what engine type it is)

But the important thing is to make sure that is the issue. Problems with Oxygen sensors, the distributor cap, ignition system, vacuum system all manifest in engine misses and it is important to identify and verify what the problem actually is.

MAG diagnosed an issue with my ECU as a problem with the throttle body, costing us a new throttle body, sensors, labour 3 times over and finally a used ECU.

One needs to be very careful in these type of issues as Electronic Diagnostic systems do not always report the root cause of the problem, just symptoms.

My tech Wasantha should be able to help you source the MAF if all else fails, but he does not have electronic diagnostic equipment so you still need to go somewhere who has a good piece of kit plug it in and see for yourself what the report says. If the your ECU is reporting MAF failiure and nothing else then its likely to be the cause of the problem. But if it reports MAF failiure and other parameters are a bit iffy or if its reporting other issues as well it could be something else, like the ECU for example.

Also does the check engine light come on, which should if the MAF sensor is faulty.

The Don

Thanx Don....,

I will try to find engine specs as soon as possible and let you know.......... :-)

[Devinda_Z]

Thanx Don....,

I will try to find engine specs as soon as possible and let you know.......... :-)

there should be a plate in the engine bay , most likely on the bulkhead which will have the engine code along with the chassis code etc...

[maithri]

Hi,

I have no knowledge of the model of car you own, but a failed Maf sensor normally will remain faulty so the problem should be there pretty much always, yours tale 100Km s to show up. To me this sounds like a component overheating and breaking down within the ignition system or in the fuel delivery i.e.injectors etc.

Have the basics tested, is the ignition coil in good order, you can test this if the primary and secondary resistance values are known and have access to a basic multi meter.

Without hearing the misfire I can't judge if it is fuel related or ignition related but I am sure if no one so far mentioned a "petrol miss" among your mechanics it is un likely.

The wildest theory here is to clean the catalytic converter, I have never heard a cat causing a misfire, a blocked exhaust will stop the car long before 100 Km, so dont waste your time or money on cleaning the cat-no way to clean it and a waste of time and money.

Sorry not possible to be more specific.

Maithri.

[Rox]

OK, now I have all correct data about the car......... :-)

Supra_Natural, you are correct the engine is indeed not 1300 l, it is 1500 l.....

Don, Engine number starts with 4G15.... Is this a common engine model in SL?

Nilantha & Don, Air Flow Sensor model number is MD178976

Guys, thenx a lot for ur interest & help.......

[The Don]

OK, now I have all correct data about the car......... :-)

Supra_Natural, you are correct the engine is indeed not 1300 l, it is 1500 l.....

Don, Engine number starts with 4G15.... Is this a common engine model in SL?

Nilantha & Don, Air Flow Sensor model number is MD178976

Guys, thenx a lot for ur interest & help.......

This is the most common engine fitted to Mitsubishi's (Its a 1500CC engine by the way). You should have no issues finding an air flow sensor at the place in Psnchikawatte I mentioned previously.

But as Maithri says you need to double check the cause of the problem before investing money in a air flow sensor.

[Rox]

I have one more question to ask;

Some time before this fault come, the timing belt failed while on the way and as a result we had to replace 6 tappets. We did a brandnew replacement for that.

Can this be a fault in the replaced tappets OR any problem caused by using old tappets and new ones together OR any tuning error in those?????

[The Don]

I have one more question to ask;

Some time before this fault come, the timing belt failed while on the way and as a result we had to replace 6 tappets. We did a brandnew replacement for that.

Can this be a fault in the replaced tappets OR any problem caused by using old tappets and new ones together OR any tuning error in those?????

I wouldn't think these 2 are related (the tappets, unless you get tappet noise at the same time as the miss) although other damage caused to valves etc should be investigated (I assume your car has an EFI MULTI system ?) also you should probably look in to the condition of your injectors . Incidentally where did you source the tappets from and how much did they cost ?

Edited January 15, 2009 by The Don

[maersk]

Thanx Don....

Yes, I also have heard that MAG City is not a good place but as the vehicle was in Kandy this was the only available place. Also I should mention that we did not took it to ######## for an engine scan.

If the vehicle is still in Kandy try B*ndula from Sunshine Auto Electrical for a second opinion. Very small place in between Mag & Katu'thota police station but opposite side of the road. B*ndula is ex-Kundasale auto & very skilled & reasonable.

[Rox]

I wouldn't think these 2 are related (the tappets, unless you get tappet noise at the same time as the miss) although other damage caused to valves etc should be investigated (I assume your car has an EFI MULTI system ?) also you should probably look in to the condition of your injectors . Incidentally where did you source the tappets from and how much did they cost ?

Actually, I don't have a skill & ear to recognize whether the nice from tappets are coming...........

Btw, yes the car has an EFI Multi system and as we have done an injector cleaning and tuning due to this issue, so they should be in good condition. Actually, tappets were from agents (According to them from Japan) and according to my knowledge 6 of them cost something around Rs. 25000/- to my father.

Edited January 16, 2009 by Rox