[Sai Narayan]

Folks, I've a strange problem with my Tiago (Petrol) - Manual - XZ Variant. Purchased Jan - 2018, ODO - 1700+ Kms

It seems like it chokes for want of petrol in second gear. This is intermittent and not always, I've tried to my best to figure out a pattern, but couldn't.
At many a times, this catches me unaware and the car driving behind me gets annoyed as though, my car may come to standstill.
I got this problem since the first week of my purchase. I reported this issue in my First Service, but that's of no use.
Since they are intermittent, I'm not sure how I would let the service person know about it or showcase in a test drive.

Suggestions are most welcome!

[Nikhilb2008]

Are you sure it's choking because of lack of fuel?

Easiest thing is to take out the air filter and clean it. Sometimes the air filter can be very dusty and cause insufficient air flow into the engine.

[akshay380]

If I remember correctly another owner (Ashok?) had similar problem. His problem was solved by changing throttle body. It was faulty right from factory.

[Nonstop-driver]

Could it be due to a faulty fuel pump? Had a similar problem with our Hyundai Accent. The problem was intermittent at first but got severe later to the point that I couldn't drive it to the service center. They replaced the pump and like was good again.

[condor]

Originally Posted by Nikhilb2008

Are you sure it's choking because of lack of fuel?

Easiest thing is to take out the air filter and clean it. Sometimes the air filter can be very dusty and cause insufficient air flow into the engine.

He says it is without a pattern. Also, no complaints of lack of power. Thirdly, it has just run 1700 odd km. Considering these, air filter should not be a problem. Even if it was, he would have had to drive thru a sandstorm to choke the air filter to that extent. Still, it would have shown lack of pickup & FE.

[Sai Narayan]

Thanks Everyone for your insight. Also checked in parallel with folks from All India Tiago Group on Facebook as I thought someone might have a faced a similar issue.

There are two options suggested, which has fixed the issue for some of them who had faced this initially.

1. Petrol Pump has to be cleaned up and tried.
2. Petrol pump and the entire air filter assembly to be replaced.

Additionally update the ECU to RN13 (If not done already).

I'm planning to check tomorrow on this issue with the Service Engineers. I've booked a time slot already. But as am not sure when the issue can / may occur - not sure whether I would be able to showcase the same to them. But clearly this seems to be an issue not just for me, but for many other customers as well - right out of factory.

[Sai Narayan]

Update : Visited the Service center yesterday. Service Center folks took for a test drive, I told them clearly I drove 20+kms to here after a brief shower in Chennai. But I did not have any issues by then and the issue is intermittent. I asked them what they have done after a couple of hrs. They said they have cleaned up the Air Filter and also did some clutch ply lubrication. I asked them about fuel pump, but the service engineer courteously downplayed it. I told him, if this issue is gonna repeat, I will come back on them heavily. But he did say, you are not able to showcase during a test drive.

So did a test drive, fortunately another intermittent issue popped up - First Gear won't lock correctly and at times I may have to try twice or thrice - same happened for the driver I notified him immediately. They again took the car to garage to lubricate the clutch ply. Not sure whether this is gonna fix the issue for me.
Total time in Service Center 11AM to 3PM.
On the way back I did not face any issues though. Keeping my fingers crossed.

Thanks so much friends for all your insight.

[Sai Narayan]

Hey Folks!!

I'm back again and here is an update.

I've been to TATA Service Center thrice(Including First Service) for the same issue. But the issue still persists. I'm planning to write an email to Customer Care with all the details, so that I can be at Peace. This is very much bothering me as I have a fear of Car stopping when actually am planning to accelerate. Also I noticed that the issue mostly occurs between 1000-1200 RPM and high chances if you're taking a U curve. Now I know how to reproduce the issue. I've also asked some well known drivers within my family to verify the issue, they acknowledge the same as well.

Not sure - whether it is related, but probably because of this I do not get mileage (within city) in bumper to bumper traffic not more than 12. One of my friends get 16KM/L in XZA and same goes for XZ as well. So this way below par w.r.t mileage too.

I'm planning to write this not just for me but for others wherever you are with similar issues and copy you guys in. But to do that, can you just PM me your email address - if interested. This not only gives them a fair idea of what am just facing but many other fellow customers like you. They may end up recalling not just us but for a larger community as well. This will also enable TATA to take this issue seriously and make sure they handle this better in Production.

Except for this niggle, I'm very happy with the purchase and will still recommend this car to my friends and family.

[ashokabs]

Originally Posted by Sai Narayan

Hey Folks!!

I'm back again and here is an update.

I've been to TATA Service Center thrice(Including First Service) for the same issue. But the issue still persists. I'm planning to write an email to Customer Care with all the details, so that I can be at Peace. This is very much bothering me as I have a fear of Car stopping when actually am planning to accelerate. Also I noticed that the issue mostly occurs between 1000-1200 RPM and high chances if you're taking a U curve. Now I know how to reproduce the issue. I've also asked some well known drivers within my family to verify the issue, they acknowledge the same as well.

Not sure - whether it is related, but probably because of this I do not get mileage (within city) in bumper to bumper traffic not more than 12. One of my friends get 16KM/L in XZA and same goes for XZ as well. So this way below par w.r.t mileage too.

I'm planning to write this not just for me but for others wherever you are with similar issues and copy you guys in. But to do that, can you just PM me your email address - if interested. This not only gives them a fair idea of what am just facing but many other fellow customers like you. They may end up recalling not just us but for a larger community as well. This will also enable TATA to take this issue seriously and make sure they handle this better in Production.

Except for this niggle, I'm very happy with the purchase and will still recommend this car to my friends and family.

If there is a clutch problem i.e. clutch slipping for any reason then there should be high wear and also occasional burning smell. It looks like more of a fuel/ignition problem. Unfortunately, the only way to resolve it is to list out all the possible reasons and examine them starting with those that are easily done without major dismantling of the engine. Hopefully many can be checked on the computer using the ECU and diagnostic programs which are available with the service establishment. Again the point I would like to make is to do a systematic fault analysis and eliminate the causes one by one. Generally the service guys are not systematic though the Tata Motors technical personnel might be more system driven for analysing faults. My own experience was that the service establishment I took my car to was mostly tilting at windmills and not doing a systematic analysis. Finally it was resolved when the Tata Motors customer service people got involved. I kept them in the loop right through.

[Amartya]

Originally Posted by Sai Narayan

the issue mostly occurs between 1000-1200 RPM and high chances if you're taking a U curve.

Another Tiago owner on TeamBhp had gotten his car's throttle body assembly and sensors replaced, but his symptoms seem to be a little different.

Any intermittent problem is hard to nail down, so the fact that you can reproduce the issue is going to help with the diagnosis immensely. Since the basic issue seems to be a lean mixture (low fuel-to-air ratio), I'd hazard a guess that one of the first thing to look at would be the throttle position sensor (TPS).

The TPS is a fairly simple device and it measures how open the throttle is at any given instant. It's a potentiometer (i.e. 3 pins, a reference voltage, a ground, and a output signal) that is connected to the throttle. As you press the accelerator pedal, the cable opens the throttle while simultaneously rotating the assembly inside the TPS to lower the resistance in the sensor assembly (i.e. increasing the output signal being sent to the engine control unit/powertrain control module). Since you mentioned an RPM range within which this issue crops up, there is a chance that the TPS has a "faulty-zone" within that range. A decent workshop can hook-up a scan tool and look at the TPS. By slowly turning the throttle assembly by hand, they can double-check if the TPS is sending a smooth output signal. There shouldn't be a sudden fall/bump in the output signal.

I think the chances of something being wrong with the mass-airflow sensor, the clutch , the spark-plugs/ignition, and the air filter is very low (mostly because how new the car is). In fact, even a vacuum leak is probably more likely (though the intermittency of the problem suggests otherwise).

Keep us posted, this is quite intriguing.

[Sai Narayan]

I would like to thank Ashok and Amartya for all your input and views.

Hello All:


I'm really sorry for the delayed response. Here is a quick update on this issue and where we are. Last time when the car visited the garage, it was the 5th time for the same issue. As Ashok mentioned, Tata folks really go with the automatic computer check, which do not yield any results and mostly it picks up issues only which are very imminent. (Not sure, I may be wrong - but that's my perspective)

So far what they did -
1. Spark Plug was cleaned.
2. Accelerator cable / Clutch cable check.
3. Software Flashed.



As per their report summary (Copied and pasted as is)

1. STANDARD CHECKS SPARK PLUG CLEANING DONE
2. STANDARD CHECKS CLUTCH PLAY ADJUSTED,GEAR CABLE
ADJUSTED

Has this solved the issue? No, absolutely not. Still I have the issue and it is very much imminent and happens at least 3-4 times a week in traffic which I am not able to figure out a pattern to report to. Problem here is I'm not able to reproduce the issue to Tata Folks.

I'm being followed up regularly by a representative / manager from TML (Tata Motors Limited) because I put this up on Twitter. Name of the gentleman is Mr. Kalimuthu.

Again today, I've given my car for the service and had a word with Service Advisor and manager from TML on the issues. This is actually my second service and it had been to service center five times so far.

I've given them a piece of advice from the knowledge that I have gained over the past 5 months on this topic but not sure how much would be heard.

Thanks for all your input, it helps me explore and keep pushing. So far I've driven around 5500+ kms and I'm not satisfied enough to write a review.

If I say I do not regret my decision in buying, it would surely be an understatement. I'll keep you posted on further updates as and when I have.

[Sai Narayan]

Hello All:

Here is a quick update after driving 7000+ kms. The issue still stands open and I'm actually in a spot to bother because I'm not able to recreate the scenario for the Tata Engineers. This looks like I just have to live with it. But in the longer run I've discovered something, I've to be always 1 gear lower than any other car that I've driven and RPM should be more than 1500 so that I don't get this choking problem. In a way I've lost hope with Tata and am planning to visit a local mechanic and see whether he is able to turn this around by any chance. I'll keep you posted.

I keep questioning over my decision to buy Tata Tiago!

[SCORPION]

Your car has 2 driving modes, eco and city. Does the choking issue happen in both the modes? Or is it specific to one particular mode?

[Sai Narayan]

Originally Posted by SCORPION

Your car has 2 driving modes, eco and city. Does the choking issue happen in both the modes? Or is it specific to one particular mode?

This happens in both the modes. How did I miss to respond!

[abhi182]

One way to diagnose this would be with a OBD2 sensor
select all engine sensors and enable logging

Next time you go for a drive, note the time when you face this issue - and later check the logs for all sensor readings around that timestamp

Try and identify the erroneous reading movement while keeping in mind what you were doing at that exact point (e.g. pressing the throttle should yield an expected upward movement in the throttle position readings)