Good Place For A Diagnosis??

GayanR · April 1, 2013

Hi guys i have a Fb14 auto GA15DE,I don't know what's wrong with this car...As some of you know i have replaced every part that these Garages asked me to replace(transmission,distributor,fuel pump)...I'm fed up doing tune up and Ecu scans and all kind of things monthly,but no one can resolve this problem.I did a tune up last month also(worked well on the tune up day) but now the engine feel like shaking and i feel like it would stop if i stop accelerating..it feels like it idles horribly low...The problem doesn't come in the morning..and also the major problem is after like 10-15 min of driving car would just stop accelerating in the middle of road, it's like a bog...so i should press the accelerator hard to get going..after a minute or so it becomes normal..again it's coming randomly.(If i switch off just for a second and restart problem goes away).(had the same problem with the previous transmisstion unit)This leads me to not driving out of Colombo,,it sucks to drive outstation.I swear after resolving this problem i will sell this piece of shit...

engine compression very good

No ecu error codes.

No fuel pressure problems.

Injectors fine,plugs fine

Replaced transmisstion is in real good condition,i suspect that the previous one was also not at fault..It was replaced due to this bogging problem..

maka basses saying their is no problem with the car,car works well on the tune up day..these things comes up after like a week.

I myself thinks their is a problem with the throttle body,one of the sensors, or the catalytic converter,silencer is clogged..plz recommend me a good place to check these sensors and stuff.I heard about A*W,do they check these things in their diagnosis..Sorry for the long story,I'm bit fed up of his car..

Edited April 1, 2013 by GayanR

Gummybr · April 1, 2013

On 4/1/2013 at 2:24 PM, GayanR said:
Hi guys i have a Fb14 auto GA15DE,I don't know what's wrong with this car...As some of you know i have replaced every part that these Garages asked me to replace(transmission,distributor,fuel pump)...I'm fed up doing tune up and Ecu scans and all kind of things monthly,but no one can resolve this problem.I did a tune up last month also(worked well on the tune up day) but now the engine feel like shaking and i feel like it would stop if i stop accelerating..it feels like it idles horribly low...The problem doesn't come in the morning..and also the major problem is after like 10-15 min of driving car would just stop accelerating in the middle of road, it's like a bog...so i should press the accelerator hard to get going..after a minute or so it becomes normal..again it's coming randomly.(If i switch off just for a second and restart problem goes away).(had the same problem with the previous transmisstion unit)This leads me to not driving out of Colombo,,it sucks to drive outstation.I swear after resolving this problem i will sell this piece of shit...
engine compression very good

No ecu error codes.

No fuel pressure problems.

Injectors fine,plugs fine

Replaced transmisstion is in real good condition,i suspect that the previous one was also not at fault..It was replaced due to this bogging problem..

maka basses saying their is no problem with the car,car works well on the tune up day..these things comes up after like a week.

I myself thinks their is a problem with the throttle body,one of the sensors, or the catalytic converter,silencer is clogged..plz recommend me a good place to check these sensors and stuff.I heard about A*W,do they check these things in their diagnosis..Sorry for the long story,I'm bit fed up of his car..

Its like going through hell isn't it?

Well from what your saying IMO it could be faulty electrics, as in the current coming to the wires and the ecu. Have you gone to your mechanic when the problem is there? Don't understand why you had to change the transmission when your problem was in the engine as you say, unless the gearbox has a mind of its own to upshift to higher gears and make it impossible to get the power down (going on 4th when you should be on 1st / 2nd).

Try a throttlebody clean up as well when you are there, maybe its clogged like mine was.

Rumesh88 · April 1, 2013

Can understand your frustration but why do you want to sell it after solving the issue? Agree with Gummybr that it could be due to an electrical fault. Just to eliminate obvious things visually check the electrical ground returns in and around(bay area) the engine and below dashboard for rusty or loose terminations. They are clearly visible.

As for the throttle body you must have got it cleaned already I believe.

Do you get the problem even when running without AC and headlights on?

GayanR · April 1, 2013

On 4/1/2013 at 4:16 PM, Gummybr said:
Its like going through hell isn't it?
Well from what your saying IMO it could be faulty electrics, as in the current coming to the wires and the ecu. Have you gone to your mechanic when the problem is there? Don't understand why you had to change the transmission when your problem was in the engine as you say, unless the gearbox has a mind of its own to upshift to higher gears and make it impossible to get the power down (going on 4th when you should be on 1st / 2nd).

Try a throttlebody clean up as well when you are there, maybe its clogged like mine was.

Hi gummybr of course it's a living hell. i have cleaned the throttle body many times,Do you have any idea where should i go to check these wiring and sensor checking stuff..Does A*W do that in their diagnosis test?

I got my transmission replaced becoz many garages here told me that bogging and sudden acceleration is caused by my failing transmission.Finally it's not

Edited April 1, 2013 by GayanR

GayanR · April 1, 2013

On 4/1/2013 at 5:08 PM, Rumesh88 said:
Can understand your frustration but why do you want to sell it after solving the issue? Agree with Gummybr that it could be due to an electrical fault. Just to eliminate obvious things visually check the electrical ground returns in and around(bay area) the engine and below dashboard for rusty or loose terminations. They are clearly visible.
As for the throttle body you must have got it cleaned already I believe.

Do you get the problem even when running without AC and headlights on?

Hi rumesh no it was just to explain my frustration but have to say i'm really fed up.Yes the problem is always there after 10-15 min of driving.No matter headlight or a/c on or off.The engine would turn rough and vibrating.And randomly bogs i can't accelartae. Do you know any good places to check these things...

k9master · April 1, 2013

Hi Gayan,

Don't know if I'm correct on this but I have a feeling that its something to do with the Mass Air Flow Sensor. In the FB14 its mounted on to the throttle body and is sealed.

How's the fuel consumption? Is it higher than normal? When you pull the plugs out do they have excessive carbon deposits?

I think guys at A*W will be able to do a scan on the engine electronics and see if everything is ok. In the Nissan GA15DE engine if the MAF doesn't give the correct voltage it does not show up as an ECU error code but will make havoc in the whole combustion process.

I do recommend Mr. Dammika Fernando of cotta road also as a good diagnostician. You can try him out as well.

If it turns out to be the MAF, you'd be better of replacing the throttle body as a whole. Advices to break the seal and repair it may work but cannot be sure for how long.

Experts, please correct if I have said anything wrong.

Hope you will soon come out of this sorrow, been there.

Cheers,

maheshw · April 2, 2013

Sorry to hear an another trouble. i too feel its a issue related to any part of your electrical system or a faulty sensor. best option is to check each & every part by taking some time with by consulting a good mechanic. it may be time consuming work but end result will be worthfull for you.

btw check your distributor too. a correct scan report will give you the exact faulty codes.

Rumesh88 · April 2, 2013

On 4/1/2013 at 5:14 PM, GayanR said:
Hi rumesh no it was just to explain my frustration but have to say i'm really fed up.Yes the problem is always there after 10-15 min of driving.No matter headlight or a/c on or off.The engine would turn rough and vibrating.And randomly bogs i can't accelartae. Do you know any good places to check these things...

As suggested by k9master you can seek services of Dhammika. However, AFAIK his scope is limited to evaluate the issue and give you advice as what to do next (I could be wrong, but that was his division of labor sometime back). There is no point in someone scanning just to get fault codes for there are none detected by the ECU according to what you have explained (No Check Engine Light). However, if it is a fault with a sensor someone with a good knowledge of the sensor readings can identify the issue by the sensor values which could be marginally operating. As you say if the issue is intermittent then it is a real hassle to diagnose but instead of blindly guessing it is necessary to crack the issue with a proper diagnosis.

Batteries · April 2, 2013

This could be due to a faulty ECU as well. Go to a good electrician & get it checked. I had a similar problem where the whole car went dead. This was due to a faulty ECU.

There is good guy at Maharagama

Edited April 2, 2013 by Batteries

GayanR · April 2, 2013

On 4/1/2013 at 7:01 PM, k9master said:
Hi Gayan,
Don't know if I'm correct on this but I have a feeling that its something to do with the Mass Air Flow Sensor. In the FB14 its mounted on to the throttle body and is sealed.

How's the fuel consumption? Is it higher than normal? When you pull the plugs out do they have excessive carbon deposits?

I think guys at A*W will be able to do a scan on the engine electronics and see if everything is ok. In the Nissan GA15DE engine if the MAF doesn't give the correct voltage it does not show up as an ECU error code but will make havoc in the whole combustion process.

I do recommend Mr. Dammika Fernando of cotta road also as a good diagnostician. You can try him out as well.

If it turns out to be the MAF, you'd be better of replacing the throttle body as a whole. Advices to break the seal and repair it may work but cannot be sure for how long.

Experts, please correct if I have said anything wrong.

Hope you will soon come out of this sorrow, been there.

Cheers,

HI K9master,You are spot on!!wow !I feel like such a looser for running after maka basses garages all these times.Went to A*W today and found out it was the MAF sensor..They said they can repair it.Are there new or used sensors for sale?or do i have to change the throttle body?? Do you have an idea of prices of a sensor unit vs whole throttle body.tanx

Edited April 2, 2013 by GayanR

GayanR · April 2, 2013

On 4/2/2013 at 5:25 AM, maheshw said:
Sorry to hear an another trouble. i too feel its a issue related to any part of your electrical system or a faulty sensor. best option is to check each & every part by taking some time with by consulting a good mechanic. it may be time consuming work but end result will be worthfull for you.
btw check your distributor too. a correct scan report will give you the exact faulty codes.

Hi maheshw it turns out to be the mass air flow sensor..Never thought it would wack the car this bad.tanx

GayanR · April 2, 2013

On 4/2/2013 at 8:29 AM, Rumesh88 said:
As suggested by k9master you can seek services of Dhammika. However, AFAIK his scope is limited to evaluate the issue and give you advice as what to do next (I could be wrong, but that was his division of labor sometime back). There is no point in someone scanning just to get fault codes for there are none detected by the ECU according to what you have explained (No Check Engine Light). However, if it is a fault with a sensor someone with a good knowledge of the sensor readings can identify the issue by the sensor values which could be marginally operating. As you say if the issue is intermittent then it is a real hassle to diagnose but instead of blindly guessing it is necessary to crack the issue with a proper diagnosis.

Hi rumesh i went to A*W today and found out it was the mass airflow sensor.I went to Mr.dhammika before but he couldn't figure it out,he was depending on ecu readings.But a good efi tune up mechanic i must say.Need to find a sensor or throttle body now.Hope things go well.tanx a lot.

Rumesh88 · April 2, 2013

On 4/2/2013 at 11:07 AM, GayanR said:
Hi rumesh i went to A*W today and found out it was the mass airflow sensor.I went to Mr.dhammika before but he couldn't figure it out,he was depending on ecu readings.But a good efi tune up mechanic i must say.Need to find a sensor or throttle body now.Hope things go well.tanx a lot.

Nice to hear of the positive outcome. It is not the readings alone a good mechanic should depend on but the experience in analysis.

BTW now that you have changed many things in the engine would you make up your mind and sell it?

GayanR · April 2, 2013

On 4/2/2013 at 1:04 PM, Rumesh88 said:
Nice to hear of the positive outcome. It is not the readings alone a good mechanic should depend on but the experience in analysis.
BTW now that you have changed many things in the engine would you make up your mind and sell it?

Haha it seems now only the engine is left to be replaced/..... To tell you this is bit of a unlucky car for me.I would use it for few months for the sake of repairing satisfaction and sell it. :music-smiley-019:anyway became a bit of a mechanic and got enlightened because of this car.Happy about that . Tanx for the help.Will post after replacing the sensor or the throttle body how things works.

k9master · April 2, 2013

On 4/2/2013 at 11:00 AM, GayanR said:
HI K9master,You are spot on!!wow !I feel like such a looser for running after maka basses garages all these times.Went to A*W today and found out it was the MAF sensor..They said they can repair it.Are there new or used sensors for sale?or do i have to change the throttle body?? Do you have an idea of prices of a sensor unit vs whole throttle body.tanx

Hi Gayan,

Glad to hear that it worked out. Well what they do AFAIK by repairing the MAF is to re-solder the circuit board. When the MAF is used over a long period of time the vibrations etc. tend to loosen the solder points which increases the resistance within the circuit resulting an incorrect voltage being generated by the MAF. The GA15 ECU is not able to detect this as a fault and uses this value to calculate the fuel to air mixture incorrectly resulting the car to run either rich or lean.

Anyways, the reason I didn't recommend the repair was that it has never been a permanent solution for me or a few people I know in the past. symptoms tend to return in a few months or an year tops. Once I replaced the TB things have been ok for over 2.5 years now.

You can get hold of a recon throttle body from delkanda area for about 10 - 12k. I honestly don't know if the MAF is available to be bought separately.

On a side note, now that you have replaced all the crucial parts I think its better you keep the car unless you are going for an upgrade. You have no idea how many cars are out there which are very poorly maintained. The economy coupled with bad financial management have left a lot of people having no option other than cutting corners in maintenance. So you may end up in a worse situation very easily...

Hope this helps.

Cheers,

K9M

GayanR · April 2, 2013

On 4/2/2013 at 2:22 PM, k9master said:
Hi Gayan,
Glad to hear that it worked out. Well what they do AFAIK by repairing the MAF is to re-solder the circuit board. When the MAF is used over a long period of time the vibrations etc. tend to loosen the solder points which increases the resistance within the circuit resulting an incorrect voltage being generated by the MAF. The GA15 ECU is not able to detect this as a fault and uses this value to calculate the fuel to air mixture incorrectly resulting the car to run either rich or lean.

Anyways, the reason I didn't recommend the repair was that it has never been a permanent solution for me or a few people I know in the past. symptoms tend to return in a few months or an year tops. Once I replaced the TB things have been ok for over 2.5 years now.

You can get hold of a recon throttle body from delkanda area for about 10 - 12k. I honestly don't know if the MAF is available to be bought separately.

On a side note, now that you have replaced all the crucial parts I think its better you keep the car unless you are going for an upgrade. You have no idea how many cars are out there which are very poorly maintained. The economy coupled with bad financial management have left a lot of people having no option other than cutting corners in maintenance. So you may end up in a worse situation very easily...

Hope this helps.

Cheers,

K9M

tanx a lot k9 you seems to have a thorough knowledge on these things.Yes repairing on things always leads me to actually replace the whole unit after few months so far.I'll be looking for a throttle body,used sensor if possible.And thanks for the advise on selling the car..I got some deals on Mazda hatchback and Nissan n16 for 18k price range.Anyway Would like to stay away from garages for a while. it's kind of becoming a drug for me.Tanx again