High Altitude Starting Problem

[barkerdl]

My truck starts on the first rotation with a single puff of dark smoke every time while at low altitudes. When I let it sit overnight at high altitudes (7000-8000 feet), it is hard to start and when it does start it smokes a lot (blue-grey) and runs rough for several minutes. After it warms up, it settles down and runs normally. This has happened several times with different tanks of fuel. Any ideas or suggestions will be appreciated!

 

[SLAY]

Whats the outside temperture, wait to start time, and voltage gage doing? Sounds more like a preheat cycle issue at that elevation.



Steve

 

[barkerdl]

The ambient temperature at startup the last time this happened (two weeks ago at Mt. Charleston) was about 80 F. The wait to start light went out at three seconds and the grid heater did not cycle (per voltmeter observation). The overnight temperature was about 50-55 F. and I did not start the truck until early afternoon when it was time to go home. The grid heater works on this truck - at least it has for the last two winters I have owned it.



Will be doing the trip again this coming weekend and will try to make other observations if anyone has ideas on what to look for.



Thanks!

 

[BushWakr - RIP]

If your overnight temps drop into low 50's or less then keep in mind that all that iron under the hood will stay cool quite a while. This may put the temp sensor in a bit of "quandry" as to whether it should by cycling or not.

Basically the smoke is, to some degree, a timing related issue.

If the timing is stock or close to it, then you'll see more smoke at startup particularily since your technically "running rich" at higher elev.

The fact that it cleans up after running a bit is a good sign and a normal one.

My truck is timed to 15* advance and I get some blue/grey at startup at sea level till it warms a bit.



JMO,



Bob.

 

[barkerdl]

Timing is stock as is the remainder of the truck except for the 16 cm turbo housing and DD Stage 1 Pump Kit referenced in my signature.



BushWakr - I take it you think this is a normal, even though annoying, condition brought about by unusual conditions at high elevations.



Running thru other things in my mind - fuel filter has 8K on it. "Should" be good as I've not had any fuel problems and always buy fuel at high volume locations. Truck runs fine - drove it to work today. I did change the air filter, so will be able to see if that helped when I go to Mt. Charleston this weekend.



Thanks!

 

[Diesel_Junkie]

My truck does the exact same thing at the higher elevations. It has not caused any problems yet, but it really sounds like crap when you start it. It feels like it is struggeling to run. (comparitively)



It is totally altitude based in the differance though. I have been going up and down from the Sierras to the bay area dozzens of times recently. 5000 feet or so doesnt really make the differance. It is only when you get to 7000-8000 that the differance really becomes obvious.



It gets really bad if it is a combination of a cold weather and high altitude start, but no real problems yet.



Should I have it timed??? Are there instructions out there on how to time a diesel? I havent had much of an opportunity to tinker with my motor, other than turning it up a little. and adjusting the valves. I spend too much time fixing the broken drive train the cummins rips up.

 

[jwdeeming]

I can't help you with ideas, but I don't think you need to settle for this as "normal" behavior. I don't know if my '01 24v should be radically different from your '92 in this regard, but I can tell you that my truck ALWAYS starts immediately, unless I forget the Wait To Start light.



My truck starts equally well hot or cold, and has been tested all the way up to 13,700 feet. Coldest start so far is -5 deg F. , without the block heater.



My Powerchoke buddy hates how quickly my truck starts compared to his.



Hope you find the solution.

JimD

 

[Dkevdog]

My truck (96') does the exact same thing to me at altitudes. At 9800'- even though the outside temp was 70*, it had still gotten very cool the night before. I found that letting the engine heaters do thier thing a few times helped. But like you said, at sea level or low elevation, even when that air temp is 40* I can start her right up without letting the grid heaters do anything.



Kev

 

[barkerdl]

My truck will start on the first rotation and run smoothly when the temp is in the 20's and 30's after sitting outside all night, but the grid heaters will run for 15 seconds at that temperature and continue to cycle for several minutes. So, if the grid heaters are engaged, the truck starts and runs smoothly - this is true for all altitutes I have experienced up to 8000 feet . BushWakr may have a point in my case - the engine may be cold in the block where it counts, but the grid heat sensor may be warm enough not to trigger the heaters.



Anyone rig a manual turn on for the grid heaters?? Perhaps not a good thing to do?? If there were a simple way to "fool" the temperature sensor into thinking the engine was "cold" and cause it to engage the grid heaters temporarily, it would be worth a try. Any ideas?

 

[fredflinstone]

Hard start at elevation

I have experienced the same problem at elevation with a 2001 and when talking with several others while living at altatude in Wy I found that it was quite common for the diesels to suffer on startup. Since the diesel does run on compression instead of spark to create heat to fire it makes sense that they would have to work harder on startup when the air is thinner at altatute. At least this is the basic conclusion I came to but I'm allways open to other oppinions! Seth

 

[nascar mark]

What works for me when hunting at high elevations is to turn key to on, wait for wait to start light to go out, and turn key off and repeat 2 more times Works wonders.



mark

 

[BushWakr - RIP]

'mark,



I'm interested in your suggestion here since I also do some late season/cold weather hunting.

The manual makes a "big deal" out of waiting the proper amount of time between hearter activations or damage could result.

Have you ever had any problems with your hearter/temp sensors, etc doing what you do?? How long do you pause between cycling?



My truck starts righ up unless it's nasty cold. But it does smoke and take some time for the idle to smooth due to the heavy/lengthy loading of the alternator by the heaters, and cold cylinder walls.



I had a "no-start" situation in temps that hit -50 *C on one occasion. That was really ugly.



Bob.

 

[nascar mark]

Hi Bob.



I cycle it right away. One after another.



Will not hurt relays Cummins says, as Cummins them selfs suggested this in one power booster news article, when someone complained about hard to start and rough idle at start. More common on 98. 5 and newer rams.



mark

 

[Gary - K7GLD]

Neither my '91. OR my new truck have the SLIGHTEST problem starting immediately and running smoothly at that elevation, and temps down near freezing - as the fella above said, it seriously annoys my Powerstroke driving bud, who has to keep his plugged in all the time, and STILL has trouble getting it started - Nearly killed him to have to have me give him a jump start...



One of my steady first line of defense methods, is to always use a good fuel conditioner in my fuel - I use Power Service - and if I detect ANY engine roughness, I add a good injector cleaner too... Has ALWAYS kept/returned my engine to smooth, reliable starting and running right up to the day I sold it at 120,000 miles with nary a problem!

 

[Whitmore]

tap on the carburator with your pocket knife I think the float is stuck

 

[Midnite]

Originally posted by BushWakr

The manual makes a "big deal" out of waiting the proper amount of time between hearter activations or damage could result.

There's no problem at all cycling the grid heaters several times--you don't have to wait any amount of time between cycles.



Could you be thinking about the parts of the manual that emphasize the importance of waiting after *cranking* the engine? That's extremely important because the starter is by no means a continuous duty device, and after cranking for 20 or 30 seconds it gets really hot and needs to be allowed to cool down.



You can cycle the grid heaters all you like without pausing, and the worst that'll happen is you might drain your battery.



Mike

 

[barkerdl]

Originally posted by Whitmore

tap on the carburator with your pocket knife I think the float is stuck

I tried tapping on the carb thingy with my Swiss Army Knife while SWMBO switched the ignition off and on a few dozen times. When the Cummins fired off a cloud of flame and smoke came out the tailpipe that started a forest fire! Diesel engines are now prohibited in the park!



Seriously, had no problems starting this weekend at 7000' and hope it stays that way. Will try cycling the ignition start sequence a couple of times next time it gives me any problems.



Thanks!