[DirtyDan]

Originally Posted by ringoism

There is definitely no risk of engine damage

For what it is worth, I have driven about 60,000 kilometers with my 2013 Thar with the air mass sensor unplugged and EGR blocked off....absolutely no problems.

I have driven about 35,000 kilos on my 2018 Thar with the air mass sensor unplugged and the EGR blocked....absolutely no problems.

I get a big increase in responsiveness and a very noticeable increase in rate of acceleration.

[ringoism]

Originally Posted by DirtyDan

I have driven about 60,000 kilometers with my 2013 Thar with the air mass sensor unplugged and EGR blocked off....absolutely no problems.

Thanks Ken, was thinking of you when re-reading this thread, glad to see you're still active here. Had seen your similar comment earlier.

I looked into the official (PDF) service manual for Getaway, realized it's NOT a full 5v signal that gets sent to the ECU when MAF disconnected, as some here claimed. What actually happens is that when the ECU doesn't receive an airfllow signal in the expected range of 0.5-5v, it is just switching to a default map which assumes: 1) 20°C ambient on the integrated temp sensor (which is close enough a good part of each year in the hills), and 2) "normal" fuel metering based on engine rpm and throttle position. Being that engine displacement is a fixed volume, then assuming a fresh air filter, unclogged intercooler, and decent overall engine condition, this assumed default airflow should be reasonably close to ideal within a moderate altitude range with "average" weather conditions, etc, etc.

Everything here then points to OE mapping problems, not hardware. We should remember that this development happened pre-Three Idiots, hill touring was more limited. And most hill folk themselves were more pragmatic on one hand and typically lower-income on the other, and would have favored (as many still do) more rugged vehicles and the good old DI's of whatever form than Scorps and CRDe Thars, which at some level (good as they are) really were originally intended for greater comfort, quiet refinement - and posing!

For the <5% of customers who were going to drive the hills in a CRDe, it probably wasn't deemed necessary to send teams to do the extended R&D, etc. As you mentioned, down in Punjab people loved these, had no issues.

Maybe therefore Team Mahindra, without much actual testing and tweaking, just got the fuelling compensation for altitude totally wrong, such that the default map runs better.

It is also possible that even BS3 norms weren't so easy to conform to with that particular engine (though DI's did it with full manual fuel systems and longer strokes), and that they were simply forced into compromises.

Whatever, on a well-maintained car running at anything but extreme altitudes/ temps, the map should be expected to run fine and is not going to damage things any more than running carburetors and manual diesel injection pumps would have in the day, 99+% of which never were compensated for altitude & temp! Throughout most of automotive history, vehicles ran on mechanically-fixed "default maps" pretty well most of the time with no issues - and that's what a CRDe with a disconnected MAF/temp sensor gives us!

Btw I am doubtful now that adding a resistor in the MAF wiring (as a few mentioned incl. me!) would help matters - because if the voltage output isn't within the specified range, a code will trigger, and it's going to switch into the same default map anyway. Depends how far away airflow at idle /max speeds put us away from 0.5v or 5v in unaltered form I guess, could be a little wiggle room there that could make a difference but may or may not be enough to make a real impact. Worth a look maybe, will try and measure this real-world operational voltage range one day.

Anyway this "Everymod" that some of the VAG guys are doing on YT generally appears to add the resistor to the fuel rail pressure sensor, which tricks the ECU into thinking pressure is lower than actual and that it must compensate by increasing pump output pressure and/or lengthening injector pulse width. Tuning boxes do the same in a potentially more sophisticated way. Hence more power - and smoke, and presumably fuel consumption when "in it", depending how badly you try and trick it or how smart the tuning box maps are.

I was wondering how your Thars have run at really high altitudes and/or really extreme temps.

I'd imagine that without mass airflow compensation, engine would run a bit too rich at high altitude. And without temp info would assume less dense air than actual at super low temps and meter too little fuel. Which come to think of it might help winter FE at the expense of some peak power.

Technically the wire to the airflow portion only could probably be clipped / have a switch added, and the temp signal lead left alone if that seemed beneficial. Pinouts are there in the manual, it would be an easy job if selectable normal (closed-loop) operation was sometimes desired or offered benefits in FE or whatever.

Whatever, it's really a shame it wasn't mapped right WITH the compensation functional. Getaway runs so effortlessly and transparently now, no need to downshift all the time below 1500-1600 rpm's, no need of severe clutch abuse, can lug it down easily to 1000-1200rpms and it will pull cleanly from there. Still no real power till boost comes in till later, but at least it isn't faltering / falling on its face anymore. And I think I'll almost never have to use 4Low just for getting started on inclines now.

Wish I'd done this earlier, wifey wouldn't have roasted the clutch that fateful night, and I'd have saved ₹4600 on the new disc...

-Eric

[ringoism]

Originally Posted by abhikb

On highway drives earlier it used to cruise at 80kmph/2000rpm, there’s a slight bump in this with speeds ranging at 85-90kmph at 2000rpm.

This change in speed at rpm is simply not possible without a change in gear ratios / tyre sizes.

UNLESS the re-mappers fiddled with the speedometer sensor input. I hope this wasn't their method of (apparently) reducing 0-100kmph times and increasing FE!!!

Are you 100% sure this change occurred? Bit suspect!

I'm glad, however, that the remap worked well for you driveability-wise, I keep thinking of getting this done on the Getaway - though a FE bias would be very helpful in my case.

-Eric

[Red Liner]

Originally Posted by KA09_BIKER_GPER

Hey DirtyDan, I just tried this on my 2015 CRDe. I think it has the same EGR as the latest model. Earlier I disconnected just the MAF and the result was really good. However I reverted as there was too much smoke at low rpm.

Today I tried disconnecting MAF and also the vacuum hose to the EGR. The result was same but there less smoke at low rpm. I need to do a long drive to confirm this.

I wanted to understand why you put a blocking plate. I am under the assumption that removal of vacuum hose will keep the EGR valve shut and prevent exhaust gas recirculation. Correct me if I am wrong.

Hi again,

Have you continued driving this way with just the vacuum hose unplugged? How has it been so far? I assume you have disconnected the MAF sensor as well. I have the same vintage Thar as yours, hence the ask...

[NomadSK]

Originally Posted by DirtyDan

For what it is worth, I have driven about 60,000 kilometers with my 2013 Thar with the air mass sensor unplugged and EGR blocked off....absolutely no problems.

Interesting, all what you are doing is spewing more NOx to the atmosphere. EGR addresses the problem of controlling NOx emissions inside the engine cylinder, at the point where NOx forms. Without EGR, the engine will run hotter and more NOx will be produced, since it is directly proportional to the temperature of the combustion, which would eventually mean higher PM2.5. Exhaust gas with fresh air makes it run cooler in the combustion chamber and thus lowering the NOx produced.

I guess both of your vehicles aren't with DPF, else you would be clogging them at regular intervals. You might get adequate power but definitely at the cost of reduced fuel efficiency, its there because a proper design creates a delicate balance between efficiency and environ norms. Your catalytic convertor might be working over time and without MAF, you would be running the engine richer or leaner with no control, I'm surprised that the ECU is not throwing any fault on the cluster without MAF, my intake air-hose got disconnected once, during the drive and there was immediately check engine light on the cluster and the car went into the limp mode.

Also I would like to know, how does you PUC check goes ?

[DirtyDan]

Originally Posted by NomadSK

.. I'm surprised that the ECU is not throwing any fault on the cluster without MAF, my intake air-hose got disconnected once, during the drive and there was immediately check engine light on the cluster and the car went into the limp mode.

I am not surprised. You are forgetting that the production of anti-pollution equipment also has an environmental impact of considerable size. Good sir, I give you credit for being one of the "good guys" in the oil and gas industry and an environmental champion of sorts....but so am I mostly, and I disagree with you on much of what you have said here and/or find it myopic.