[anupmathur]

Originally Posted by gd1418

Suman Ghosh, a member of our scorpio forum and owning a CRDe SLX had this problem the most at all places - Leh, Jispa, Pangong Tso, Hunder, Tso Moriri and other high altitudes where we camped for the night, except Manali .

He had to use the primer fuel pump in the bonnet quite a lot before the vehicle fired. Even Roshun experienced this and had to pump.

Thanks for this info, GD.
Is there a resolution to this issue? What is the status with these two Scorpios?
I certainly would like a no-hassle start each morning! Having to pump manually is not an acceptable solution.

[SS-Traveller]

It seems great men have greatly interesting problems, Mathur-saab! In short, what I figure out is this:
Your (and a few others', but not all) Scorpio 2.6 CRDe refuses to start at high altitudes, but not necessarily at very cold temperatures - i.e., it would start fine at MSL at 3*C but not at 9000 feet ASL at 8*C.

Originally Posted by suman

The rarefied air I'd think? Not necessarily the low temperature? If it was low temp, you'd face it even in Delhi on the occasions when temps plummet. I don't think you've ever faced it in the plains have you?

If the rarefied air is the issue, as you say, Suman, then with all things being equal, none of the Scorpios with the same engine woud start there - but apparently some do and some don't.

Originally Posted by wanderernomad

Add a small quantity of Kerosene in your diesel when in high altitude areas. Works like magic for those cold starts.

Kerosene in diesel prevents the coagulation of diesel in severely low temperatures. At, say, 8*C, adding kerosene to diesel may not be of any help.

And there are no errors in your ECU, Mathur-saab, as you say, on repeated testing.

What I would figure is that with low oxygen in a rarefied air, your injectors are not putting out a fine enough mist for the mixture to fire. One suggestion: Take out the injectors, fix them to a test bench, and check the spray pattern, in comparison to a new injector. Maybe a simple service of the injectors would do - or in extremis, new injectors will sort out the problem (and burn a hole in your pocket! )...

Me, I'd give it a try once again after running a few tankfuls of System-D or STP or similar... and then open up the injectors if the issue persists.

Er... Mathur-saab, when do we go test out my theory?

[anupmathur]

Originally Posted by SS-Traveller

What I would figure is that with low oxygen in a rarefied air, your injectors are not putting out a fine enough mist for the mixture to fire.

DocSS, I wish that were the case.
How would the oxygen content change if I try starting late morning instead of early morning?
And if atomization is not optimal it should manifest very clearly in cold weather.

Further, injectors that are not atomizing correctly are generally dubbed as 'dripping' or 'leaking'. Both of these would show a heavy penalty in terms of FE (and performance, if carefully observed), which, frankly, has not been the case.

Originally Posted by anupmathur

The temperatures when I've tried have always been greater than 15° celsius, thus I'm ruling out temperature as being the sole reason.

Originally Posted by anupmathur

Interestingly, if I delay the morning start to late morning, there is no problem!

I tried this at Kharapathar. Tried at 0630 hrs - no go. Tried again at 1030 hrs - fired first shot! Temperatures were between 18 and 22° celsius.

The injectors being taken out for a test will be done only if M&M insist.
I'm nearly paranoid about having things just opened up for aimless investigation. Such practices always lead to more problems than they solve!

BTW, I've been a regular user of SysD and regular diesel.

And my car's extended warranty is still valid.

[gd1418]

There was this very interesting phenomena at Tso Moriri. Here, Roshun parked his vehicle on a gradient with the nose pointing down towards the slope. He reasoned that due to gravity, the fuel would be full in the lines and the need to pump would not arise.

And lo behold, he probably was right. On the third crank in the morning his vehicle sputtered to life. Mind you the temperature in the night was reported to be -7. We were shivering even with warmers, sweaters, jackets, gloves, cap and with two quilts thrown in the night.

I forgot to mention one more thing - my car is equipped with a electric fuel pump that is installed before the fuel filter unit. So, the fuel pressure in the lines in my car was full and probably that helped in starting.

But in Tso Moriri, where it took quite a few cranks, I suspect it was because of the cold. The engine used to fire and die down like the older Ambys & Fiats used to do in winters. One, then, used to pull the choke to start. After a couple of hiccups, my scorpio fired, spluttered, missed, shuddered and then held steady and slowly became smoother.

I was using the Chevron Delo 400 SAE 15W-40. Probably in that cold the oil got thicker. Maybe the 5W-40 would've performed better.

Leh was the only place where I saw Scorpio taxis. We should've contacted one of them to find out, what remedies they had done for these problems. I also saw Qualises, Sumos & Boleros doing the run there. It would have been interesting to know from them if they faced these kind of issues and what they did about it?

Since these two scorpios behaved like before after reaching Manali, probably the owners didn't pursue the matter...

Originally Posted by anupmathur

Thanks for this info, GD.
Is there a resolution to this issue? What is the status with these two Scorpios?
I certainly would like a no-hassle start each morning! Having to pump manually is not an acceptable solution.

Installing an after market electric pump should free you from this supposedly expected problem..

[SS-Traveller]

Interestingly, if I delay the morning start to late morning, there is no problem!

I tried this at Kharapathar. Tried at 0630 hrs - no go. Tried again at 1030 hrs - fired first shot! Temperatures were between 18 and 22° celsius.

Mathur-saab, you ever thought of investing in a few really loud alarm clocks? You've got a car with a hypersomnia disorder, I see here.

Originally Posted by anupmathur

DocSS, I wish that were the case.
How would the oxygen content change if I try starting late morning instead of early morning?
And if atomization is not optimal it should manifest very clearly in cold weather.

Cold weather + low oxygen just keeps the mist below flash point?

Further, injectors that are not atomizing correctly are generally dubbed as 'dripping' or 'leaking'. Both of these would show a heavy penalty in terms of FE (and performance, if carefully observed), which, frankly, has not been the case.

As the injectors heat up, they clear up a bit, so you face no issues when running a warmed-up engine? As GD said, manually pumping up increases the pressure at the injectors, a finer mist forms, and voila... a quick start.

The injectors being taken out for a test will be done only if M&M insist.
I'm nearly paranoid about having things just opened up for aimless investigation. Such practices always lead to more problems than they solve!

I agree... and so I said in not so many words in my last post...

Originally Posted by SS-Traveller

Me, I'd give it a try once again after running a few tankfuls of System-D or STP or similar... and then open up the injectors if the issue persists.

Originally Posted by anupmathur

BTW, I've been a regular user of SysD and regular diesel.

Try something else - like STP...

And there was no answer to my last line! I'd like to see what the problem really is, on-site... So when do we go there and find out?

[anupmathur]

Originally Posted by SS-Traveller

So when do we go there and find out?

LOL, Doc, what an invigorating thought! I'm trying to figure where we should head to so that the experiment can be done with an M&M service centre nearby so that they can send a man early morning with the laptop!
Any suggestions?

Originally Posted by gd1418

...We should've contacted one of them to find out, what remedies they had done for these problems. I also saw Qualises, Sumos & Boleros doing the run there. It would have been interesting to know from them if they faced these kind of issues and what they did about it?

I can tell you what they did about it! They did not buy the CRDe!!
Hence the M2DI.

[SS-Traveller]

Originally Posted by anupmathur

I'm trying to figure where we should head to so that the experiment can be done with an M&M service centre nearby so that they can send a man early morning with the laptop!
Any suggestions?

Sure - let's get hold of one of M&M's service engineers at Delhi and take him along for the ride, laptop and all. If he still doesn't figure out what's wrong, we can jettison him on the way back...

[suman]

Originally Posted by gd1418

Leh was the only place where I saw Scorpio taxis. We should've contacted one of them to find out, what remedies they had done for these problems.

You probably didn't notice but like he says below, the Scorpio taxis all along the route were either nonCRDEs (like yours) or M2DI -

Originally Posted by anupmathur

I can tell you what they did about it! They did not buy the CRDe!!
Hence the M2DI.

Originally Posted by SS-Traveller

Cold weather + low oxygen just keeps the mist below flash point?

So isn't that what rarefied air is all about then? And such problems wouldn't necessarily happen on ALL cars but probably a few depending on a combination of factors - injector health, air filter cleanliness etc..........

[Roshun]

So we are not alone :-)

Suman Ghosh and I had the same problem at high altitudes. Suman's was worse, but mine too needed about 10-15 pumps on the primer pump and it would start after that. This problem started off at Jispa (12,500 ft) and carried on all through the trip, till we got back to Manali (9,000 ft). From then on no problems.

I think it's a form of high-altitude sickness with a particular batch / model-year of Scorpios. I think Anup's is also a 2006 model year. Mine is an April 2006 4WD dx crde and Suman's is a 2006 June/July model.

Stopping it on a slope helped, as the problem I discovered was that the pump wasn't able to feed enough fuel at low temperature. So in Tso Moriri I parked it on a slope, front facing downward, and it cranked without much trouble at minus 7 degrees. Fired in the second crank, with a bit of sputtering.

Interestingly, Anil who owns a December 2005 CRDe Scorpio had no trouble with starts whatsoever. In Tso Moriri, parked on level ground, his fired to life in the second crank. All other places, first crank. He had got his injectors cleaned just before the trip - maybe that was a helpful point. Suman and I hadn't got it done for more than 15K km before the trip.
Else it could be that we have a bad batch of fuel pumps.

GD1418 of course has an electric pump installed in his Scorp (2004 GLX non crde) and that aided with the starts. He didn't have much trouble (other than bellowing clouds of black smoke) at most locations except in Tso Moriri where the extreme temperatures did make it take a while to start.

Probably M&M needs to look into this. It may be a design fault of sorts.

Cheers,

[gd1418]

Only after you, along with Anil disabled the EGR valve at the parking of Hotel Rafica in Leh and in the process losing the locking pin... I still haven't managed to get a replacement.

Everytime I opne the bonnet and see the taped "jugaad" my heart bleeds.

Originally Posted by Roshun

GD1418 of course has an electric pump installed in his Scorp (2004 GLX non crde) and that aided with the starts. He didn't have much trouble (other than bellowing clouds of black smoke) at most locations except in Tso Moriri where the extreme temperatures did make it take a while to start.

[suman]

Originally Posted by Roshun

Suman Ghosh and I had the same problem at high altitudes. Suman's was worse, but mine too needed about 10-15 pumps on the primer pump and it would start after that. This problem started off at Jispa (12,500 ft) and carried on all through the trip, till we got back to Manali (9,000 ft).

Sorry, my mistake, I'd thought the problem was with Anil's car

Anyway, I think you've now cheesed off Anup no end - he hates being part of a "design fault"

[anupmathur]

Originally Posted by suman

Anyway, I think you've now cheesed off Anup no end - he hates being part of a "design fault"

LOL, with these 'design faults' becoming more the norm than an exception, I've begun to suspect that maybe I am a design fault myself, looking for fault free products!

[gd1418]

One more puzzling phenomena encountered by me was the fluctuating engine temperature. Let me explain:

This I stumbled upon while descending from the passes. While climbing or driving on flat surface the temp gauge showed the optimum temperature, but while descending I saw that the tempgauge needle used to go down gradually to C position. When it happened the first time I radioed to the gang and asked if they too were experiencing this. While their's did to an extent, it was not like what my gauge showed. The needle at C.

The engine was running absolutely cold. I suspected the malfunctioning of the gauge the first time, but the needle started climbing up when I hit the flat surface after descending from the hill and then reached its optimum position.

I've not found any tangible explanation to this till now.

[hvkumar]

Originally Posted by gd1418

While climbing or driving on flat surface the temp gauge showed the optimum temperature, but while descending I saw that the tempgauge needle used to go down gradually to C position. The needle at C.

I faced this problem in my Matiz during my 2 drives in Ladakh. And have faced the same problem in my Scorpio in Uttarakhand.

[anupmathur]

Originally Posted by gd1418

I've not found any tangible explanation to this till now.

While descending, the fuel cut-off is at work, if you are in gear (as you should be, during descents). With very cold ambient temperatures and no combustion going on, the coolant temperature rapidly drops with chilled air flowing past the radiator.

This issue is possibly also to do with less than perfect siting of the coolant temperature sensor, which is why not ALL cars will show the same behaviour.