[tsk1979]

Originally Posted by rrsteer

Tsk, is that a problem related to the drive by wire system?

Nope

Originally Posted by 4x4addict

The volume was very faint but listening to your engine the sound/engine rhythm did not seem to change with the change in the RPM meter. You probably know better since you can hear/feel the engine better. A possibility is a faulty RPM sensor or meter.

The windows were rolled up. Thats why. I can clearly hear the engine note change. And this stops once engine warms up. Sometimes it happens on warm engine

Originally Posted by dadu

There is definitely a surge but there can be many reasons for it, fuel quality, carbon and/or something mechanical.

If you want to take my honest advise, put System D for atleast 2 tankful to rule out the fuel/ carbon, pls try it.

It did not go away even after injector cleaning. Its been there since past 7-8000kms
Some people say its due to EGR not properly working when cold.

[kingshukt]

Yes, I too have this issue - had it from day one - BUT only on a cold engine. This situation continues untill the engine is heated up. If I have to stop at a traffic signal with the enggine still cold (the temp guage still at the lowest), and the AC is on, this surge is again evident. I then shut off the AC, and the flickering of the RPM needle subsides.

This phenomenon is not so apparant if I have flushed the engine, EGR, exhaust system etc by revving up to 4500 RPM (in short bursts) in the recent past.

The flickering even in the video is minimal. It seems like the ECU is adjusting to the surroundings before settling down. Safari 2.2 does not increase the RPM of the engine if AC is on. (I had queried about it in the initial days itself) so maybe ECU is adjusting to the AC or something.
This phenomenon was there in all the vehicles in the show-room including the TD vehicle (a 4*4 Vx)

Dadu - your EGR is new (has lesser carbon deposits in it). Do you see this phenomenon with the new EGR? Do you recollect this phenomenon with your earlier EGR ?

EDIT: I recollect something in the manual about driving slow till the engine is heated up. Will check it again today evening.

EDIT 2: Saw your last post (above) after I posted so just thought I should share my views.. Yes carbon deposits do build up in the EGR. some of these deposits stick to the diapragm, springs etc. When the engine is heated up the hotter air loosen some of these deposits and is then flushed out to the exhaust. The EGR then works better. Hence my question to Dadu

[tsk1979]

In my case the surging comes even without AC.
Sometimes it comes on warm engine, but mostly its on cold engine.
Its summers in Delhi now, so engine is never really very cold
In winters the surging was very much.

[kingshukt]

Please try to flush the EGR and exhaust system by revving up the engine (preferably on a warm engine).

Please let me know if there is any improvement.

[tsk1979]

Every few 100kms I clear carbon deposits by revving to 4500rpm on warm engine.
But no effect

[kingshukt]

Now I have run out of probable solutions. especially when you mention that this phenomenon is also seen on a warm engine and also without AC. I will rack my brains somemore and will revert back if I get some more brainwave(s).

I will meanwhile see whether I also get phenomenon on a warm engine also. Never really looked properly.
Our fuels are not exactly world class and as such Dadu may have a point in his earlier post on the subject.

I however suggest that you should not look at this phenomenon with a suspicious mind - it may difficult for you considering the various incidences that have occurred to you in the recent past.

[dadu]

Originally Posted by tsk1979

Nope

It did not go away even after injector cleaning. Its been there since past 7-8000kms

Some people say its due to EGR not properly working when cold.

I dont think they have ultrasonic cleaners, I dont have any faith in the other methods they use for cleaning (i.e. the pressure one). System D does a better job than them anytime, it will also clean the EGR.

Originally Posted by kingshukt

Dadu - your EGR is new (has lesser carbon deposits in it). Do you see this phenomenon with the new EGR? Do you recollect this phenomenon with your earlier EGR ?

When the engine is heated up the hotter air loosen some of these deposits and is then flushed out to the exhaust. The EGR then works better. Hence my question to Dadu

No issues like this in old or new EGR, anyhow the PEA in system D helps with cleaning sticky valves/ springs and carbon.

Originally Posted by tsk1979

Every few 100kms I clear carbon deposits by revving to 4500rpm on warm engine.
But no effect

This method is not as effective as using System D, use system D for first 2 tankfull and then you can use it one tankful every quarter, just try once before you can form any opinion.

Please post once you have tried it. I cannot think of anything else as a remedy for this at this point of time.

[kingshukt]

Now I have a question and I admit .

EGR = Exhaust Gas Recirculation. How does adding an additive in the fuel (diesel) affect the EGR which only recirculates the exhaust gas for NOx reduction and preheats the incoming air for combution.
I admit that there may be traces of diesel fuel in the exhaust but CRDi engines run at very high line pressures and the compression ratio is also high enough to ensure that majority of the fuel is burnt.

Edit: Also I under that Particulate Filters are not part of our EIII engines. As such fuel and air mixtures are not injected directly in to the exhaust lines to prevent PM filters from clogging.

[dadu]

Additives having PEA's have a chemical composition capable of performing the cleaning action even after burnt and hence they are effective in removing/ reducing carbons.

I dont have further insight into it but know it works, have seen this work myself incase of the EGR "krr" noise problem.

[condor]

@Dadu, Tata does not recommend additives for DICOR engines. Are you still using System-D on your Safari ? What's the result & general behaviour with System-D ?

(With their TCIC engines, System-D really helps).

[dadu]

Originally Posted by condor

@Dadu, Tata does not recommend additives for DICOR engines. Are you still using System-D on your Safari ? What's the result & general behaviour with System-D ?

(With their TCIC engines, System-D really helps).

Not again, phew!!

I am yet to see an authentic document on this, everyone just keeps posting this on hear-say.

Their website does and so does Delphi.

And above this, I cant understand why it should not be used. They are used world over in CRDI engines so whats different here.

I dont know how many times I have posted these links, but noone is able to post the "not recommended" ones.

[rrsteer]

Originally Posted by dadu

Not again, phew!!

I am yet to see an authentic document on this, everyone just keeps posting this on hear-say.

Their website does and so does Delphi.

And above this, I cant understand why it should not be used. They are used world over in CRDI engines so whats different here.

I dont know how many times I have posted these links, but noone is able to post the "not recommended" ones.

Is there a way to copy paste your knowledge of the 2.2 into my brain

[Shyamtanu]

Originally Posted by tsk1979

In my case the surging comes even without AC.
Sometimes it comes on warm engine, but mostly its on cold engine.
Its summers in Delhi now, so engine is never really very cold
In winters the surging was very much.

This is something common across type of engines i.e. SI and CI engines. I have done some investigation on this myself. I have this in my Fiero F2. Tanveer, these are my deductions -

1. This can happen to engines which have impurity in the fuel or there is some dirt in the fuel lines or exhaust, as mentioned by members already.
2. Another reason is, and this seems more logical to me as far as my experience goes - the engine oil viscocity changes with temperature. Once the engine oil is slightly warmer, the oil becomes more viscous, so you will experience less spikes, as the operations become smoother. This is the key factor, why all manufacturers suggest an idle warm up before you venture out first time in the day.
3. Like the engine oil, fuel is also cold, so are the fuel lines, and the property i.e. volume and density changes with temparature. Till the engine warms up, you may get uneven fuel quantity being injected in the cylinders, due to mix of cold and warm fuel... so you get the surge (trust me, this is one very potential reason).

Reslution -

1. Make it a practice to have an idle running everyday (I used to do it in my car once I noticed this in bike, and it works!)
2. Change engine oil regularly, and get your cylinders & injectors cleaned (this ain't easy on the pocket I know, also without a good reason one should not open up the heart)
3. Use best quality fuel... like our body cannot withstand bad blood, engines cannot withstand adulterated fuel.

[kingshukt]

We are all suspecting the engine, fuel etc for this phenomenon.

Let us look at the tachometer for a change.
1. The damping of the needle plays a part in the flicker. It is afterall a machine and no 2 machines are alike, The damping will vary from tachometer to tachometer.
2. This is a elctromagnetic tachometer. A tap has been taken from the alternator and the alternator speed has been calibrated into Engine RPM.
2a. The regulator in the alternator is also suspect. This is, I think, a contact type regulator with carbon brushes (contacts) with the slip rings on the alternator. This is a removable / changeable regulator (I think) and needs to be changed after the (spring loaded) brushes wear out.
3. The electric contact on the back of the speedo console is another suspect. Loose contact there may result in the eratic behavious of the Tachometer.
4. The contact at the tap & earthing of the alternator should also be checked.

TSK - This is all that I could think of after my brains. Will come back if I think of something else.

[anupmathur]

Originally Posted by kingshukt

We are all suspecting the engine, fuel etc for this phenomenon.

Let us look at the tachometer for a change.

LOL, Kingshukt, TSK has already said the engine sound can be clearly heard! There is fluctuation of engine rpm!