Change in altitude

[aloharovers]

Aloha.
Recently moved from sea level to 6400'.
And when I go wheeling I am up 9-10000'.
I am definately getting a lot more black smoke, but I am also having a lot harder time starting.
And after starting the white smoke continues for a long time, like 1-2 minutes on a 60 degree day.

I thought maybe it was a bad fuel issue. The truck sat parked for a year while I was off playing in the desert. So I drained the fuel tank, replaced the filters (dual Rancor 60). No change.

This is a 1984 J 6.2 with 6.5 heads, entirely rebuilt less then 10k miles ago.

I am guessing I should turn down the fuel some to correct the almost constant black smoke, but wondering what else I might need to consider.

I do have a problem with #5 cylinder causing white smoke for 5-10 minutes. Checked compression in all 8 cyliners, and they are all within 10psi, #5 is right in the middle of the pack.
I have moved injectors and glow plugs around with no change. I know its #5 because if I loosen that line, the problem goes away.
I replaced the steel lines, no change.
I have clear return lines and no bubbles.
I am thinking there is a problem with the pump. This is a problem that developed before deploying. Since getting home and moving its getting worse.

So how do I turn down the fuel myself? All my books are still packed up and I can't find my articles.

When I can afford a new pump should I get a newer mechanical, if so which one?

WHen I order one should I tell them what elevation I am driving at?

Anything else I should do/try/look at?

Thanks
Pete

[john8662]

Good thing you changed out the fuel filters thats always a first in troubleshooting an issue like this.

I have a question for you, why do you think you need to turn down the injection pump fuel delivery? Have you turned it up at some point? If not there can be some causes, namely how well is the engine getting air, dirty air filter? You don't have an EGR intake manifold do you? I notice the J specification, so you shouldn't, if you did I'd say this is where the smoke is coming from.

Onto #5, you're getting white smoke when you run the engine with this injector contributing? If so, I'd say it could be a bad injector, you can swap out injectors to another cylinder and see if that cures the problem with that hole.

If you're going to have the injection pump rebuilt. I don't think they need to know the altitude that you're going to run the engine at. You will adjust for the altitude by advancing the timing. I belive it's add 2 degrees BTDC for high altitude. The timing on your rig could certainly contribute to the white smoke at idle and the hard starting. You should probably have the engine timing checked or adjust the timing. I'd say a good spot would be to use the timing spec of 3.5 degrees BTDC.

[TimK]

Pete,

Altitude will definitely cause problems. Whenever I took my Sub to my dads place in Northwestern Wyoming, about 6900 feet elevation I had similiar problems. Of course my engine had 170K miles on it. At sea level it was fine but at higher elevation my symptoms were the same as yours with exception to your cylinder number 5 issue.

Turning down your pump would cut down on the black smoke. This makes sense since your air density at high elevation is lower. (Just the opposite affect from putting a turbo on it.) Of course the best cure for the black smoke is to get a turbo. Starting would still be a problem with or without a turbo.

When I used to run a 2.25L diesel in my Series Rover in Wyoming, I had to advance the timing just a hair to help with the starting.

I don't know what to tell you about cylinder number 5 but it sounds like it's not getting enough heat to that cylinder or that cylinder is a little retarded on timing. Maybe the pop pressure is off on the injector causing it to fire too late?

TimK

[aloharovers]

Tim & John,
thank you for the replies.

I do have a diesel timing set up for the 6.2
When I built the engine I set it to 'factory', course dont know what that was.

I have never turned up my fuel, I was getting (still am) plenty of power. I just thought that excessive black smoke might mean I need to turn it down now.

Yes, J engine and intake, no egr.

I have an Amsoil air filter and did clean it. Also did a quick run around the block with no filter at all and still plenty of black smoke.

I know that as long as I keep my eye on the EGTs its not really an issue, except to the guy behind me.

I will try andvancing the timing a couple* and see how that does.

As for #5. Yeah I have moved all of the Injectors and glow plugs. Basically swapped them drivers side for passenger side and no change.
I also moved all of the glow plug leads around so they are on different cyclinders, still #5.
I have the newer style glowplugs that you can leave on like for ever and not worry about them malfunctioning. I installed a manual override switch and if I leave the glow plugs turned on while the engine is running there isn't an issue with the smoke.
I am considering placing #5 on its own cicuit and switch with an idiot light on the dash. Just leave that one plug turned on until the engine heats up.
It is excessive amount of smoke from the one cylinder too. I can't see across the street I have such a large smoke screen going. The cylinder continues to smoke like this until the engine reaches op temps.
I have a dual H2O temp gauges, one sender on each side and they read within 5* of each other all the time.

I have no idea why one cylinder would be running colder then the others, also not sure how to check for this. I do have one of those IR thermometers and guess I could take readings around each injector and see whats what.
Anyone know of some type of thermometer that you could place in the glow plug hole that would check internal cylinder temps?

We had been discussing this problem when it first popped up in Oct 03 and noone really could figure out why just one cyl was white. Since all 8 have same compression, and its definately in #5, not related to injectors or glow plugs.
Someone did think it was possible for my IP to be bad, and just had a problem with the one cylinder.

Pete

[jcomp]

Possibly there is a problem with the valve train for your #5 cylinder. Maybe a lifter?

I live at 7800ft, when I got my new 4911 IP I had to turn it down a lot, 1/2 turn. What are your EGTs?

When I brought my truck up here from lower altitude I did not notice any more difficulty starting. When I am camping overnight in the mountains, 10K-12K ft, I've never noticed that the truck was much more difficult to start in the morning.

Out of curiosity, what kind of lift pump are you using? Have you tried bleeding the fuel system before a cold start to see if it helps?

[aloharovers]

Well I bumped up the IP timing a little. Instant change in cold start and amount of white smoke.

Amount of black smoke has decreased also. Its still there how ever. I do think I am going to turn the fuel down some.

Since moving here I haven't really been out of town or anything. Yesterday I went on a trip with the local Rover club. Drove up I25 to Denver then West on 70 to Idaho Springs.
I noticed engine temps really started to climb as I was going up Monument, but nothing to really worry about. Different story leaving Denver. I had to pull over a couple time to let the engine cool down. I never let the EGTs get above 1000, made sure I wasn;t getting any black smoke, and I was pulling over when the engine hit 230. It would drop back down to 190 in about 5 minutes, drive a couple miles and pull back over.

I think that the cooling is two issues:
1. I thought I should lower RPMs when it starts over heating, so I was keeping her around 2000. Just read in the 6.2 trouble shooting guide (yeah I found the right box of books to unpack) that I should have been up between 2500-2800.

2. My oil cooler placement. Because this engine is inside an old Land ROver I didn't have a whole lot of space, no way to fit a stock GMC radiator. So I am running a HD aluminum radiator. I had read somewhere that your radiator should have the same square inches of surface area as you engine displacement. So I have a 20"x20" radiator.
In front of this is a 2"x10"x20" oil cooler.

So as well as not running the right RPMs I have the oil cooler effectively blocking half the radiator.

I believe I have come up with an effective, if not unique way of dealling with the oil cooler. The cooler has a dual 10" electric fan. All together the entire set up is 21x11x5. I am using braided hose for the cooler lines so can put it where ever I want. My plan is to build a hood scoop and mount the oil cooler in that.

I also have a Peninsular hi flow H2O pump that I will install.

I have an electric lift pump. I will grab a low pressure gauge and check pump out put, as well as excessive pressure in the IP return line.

I have a number of things to look at, change, install. Moving the oil cooler and checking fuel pressure are at the top of the list.

Pete

[Stray Cat]

Stock timing on 6.2L is 6-degrees ATDC. It is reccomended to retard IP timing 1-degree for every 4,000 feet of elevation above sea level.

[aloharovers]

OK,
I bumped up the IP Timing just a smidge.
I turned down the fuel between 1/8 and 1/4 turn.
Put in a new cooling fan, the hi-flow water pump, and a new thermostat.

Truck starts right up, white smoke only last a few seconds.
The black smoke is now only present on hard acceleration, just as it should be.

Truck is still running hot on steep highway climbs. Need a bigger radiator I think. :(

Pete

[john8662]

What thermostat are you using? I only recommend the Robertshaw thermostats or a factory AC-Delco stat. The Robertshaw you can get a 180 in, but the AC is only 195.

Here is a little more info in this post:

Here (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=2;t=003682)

[aloharovers]

Originally posted by john8662:
What thermostat are you using? I only recommend the Robertshaw thermostats or a factory AC-Delco stat. The Robertshaw you can get a 180 in, but the AC is only 195.
Thanks John.
I will order a Robertshaw 180. I currently have a Stant 180.
I even tried running without the t-stat. Didnt make any difference.
I also ordered a new radiator. 27x19 core versus the current 19x19 core. Pretty sure that will sove this problem.