ISX

I just got schooled on how to do all the library research crap at college and of course I went after diesel topics while I'm on break (now) and I just found something incredible that answers a LOT of problems that most of us don't have the means to prove/disprove. It is a PDF and I think it is public, guess I'll find out when I go to jail. I'm pretty sure its a publication on the internet but I can never find stuff like that through google. Anyways, there will be questions about all the acronyms and I already spent a while finding them all so I'll make your alls life easy lol. IMEP--Indicated Mean Effective Pressure: Basically the compression pressure of an engine. MFB50--Mass Fraction Burnt 50%: When half of the fuel has been phase changed (into heat), so basically the point of combustion. I assume they average the start and end points of fuel combustion so they have a single "point" of combustion since the process of the fuel combusting is not a point but rather a range.. I think this is all of them. The file is a PDF meaning you need abobe reader to open it. EDIT: I just noticed a lot of definitions are at the very bottom of the file, so scroll to the bottom of it for stuff I mighta missed. Between that and what I posted under here, you should be all filled in. CRC [Fuels]--:is a company HCCI--Homogeneous Charge Compression Ignition: Fancy term for a diesel engine, or the diesel principle rather. ISFC--Indicated Specific Fuel Consumption: Measure of fuel rate. NOx--Nitrogen Oxide: Pollutant that emissions try and control. HC--HydroCarbons: Another emissions pollutant. CO--Carbon Monoxide: Another emissions pollutant. Aromatic%--: I think this has to do with emissions from the exhaust, maybe soot levels. Lambda--: Air to Fuel Ratio T90--: Temperature where 90% of the fuel volume evaporates. This means T50 is when 50% evaporates.. Pub15621.pdf

I wasn't really trying to chew you out..just saying those subtle things are the things were the things we needed to know.. Any cummins not running top notch is a cummins with a problem.. so any little thing is a clue. Though having had my timing way advanced I do know what you mean by it runs OK. As for the timing deal, you had high EGT's mainly during low RPM. What really advanced timing does is shoot in the fuel really early, way before the piston has reached TDC. Well at low RPM, there is a relatively long amount of time between the injection and TDC. This means the fuel ignites before TDC and is actually trying to turn the engine backwards since it is blowing up while the piston is still trying to come up (compression stroke). This effect is actually part of why advanced timing causes the louder knock. But at low RPM, this is horribly inefficient and causes high EGT's because you need more fuel to drive the truck and overcome the wasted power. When the truck is cold, it doesn't start because it is shooting the fuel in so early that the piston hasn't gone up enough to create enough heat from compression, so it doesn't ignite. My timing is at 13.5 yes. I think. Either that or 14.5 I can't remember. I hate losing low end power and startability. You being in texas I would set it more at the 14.5 mark. On a side note, overly retarded will have a similar reversed effect. It will start up so fast that you won't believe it. Have low end power like you won't believe. And be the doggiest thing in the world over 2000RPM to the point that the only thing that changes when you floor it is the EGT gauge.

This whole time you have been saying it runs perfect and barely smoked but the usual bit when you floor it... That thing is way advanced on timing, just like I suspected. When the timing is advanced really far, it is set up to be efficient at high RPM, and in your case it sounds to be over 20* advanced. The low power will suck, it will smoke, it will have no boost, it will knock like a 24V... It has no efficiency down in the lower RPM. At cranking RPM you might as well forget about it starting because the engine is cold and it is injecting way before the piston hits TDC so there isn't near enough heat built up yet. Ideally the engine should be around 0* while starting, maybe 8* idling, and around 14* at 2000RPM, maybe 20* at 3000RPM. You advance it because the engine moves so fast that you are trying to beat the fuel delivery delay so that it detonates right around TDC, hence the reason you have to keep advancing it for higher RPM. Sled puller trucks running over 4000RPM are running into the high 20's* with timing. The injectors being bigger spray a little bit bigger droplets which take longer to absorb heat and combust, retarding timing (helping out your overly advanced situation). Did the timing light guys mark TDC on the damper or put timing mark tape on it or did you not get to see it? I'm just wondering if they just "told" you it was at 15* to get your money, cause that thing is way too advanced. A true 15* setting would make the truck start fine and it would really be just a tiny bit different than stock. Here is mine when it was over 20* on a 56F morning start.. http-~~-//www.youtube.com/watch?v=DLfiWV2Tg7g

If you do take the entire turbo off (draining the oil out of it) all you have to do is get a socket that fits that front nut and use an extension and a wrench and then start the truck and wait for oil pressure. The turbo has hardly any power at idle speed. I know it spins pretty fast idling but it is easilllly held back with the socket wrench. Just don't rev it up while you're doing it.

The timing thing is really the only thing that seems to be the culprit. My turbo shaft is actually brand new so it spins a little better than usual. Over time they get a little oil coking on them and it might not look like much but when you talk about something spinning 100,000RPM it starts to really have an effect. Not too much but down low it seems to spool better. Set your valves a little tighter, such as 0.017 exhaust 0.008 intake. The thing about timing making it have issues is what really interests me. Is the EGT issue the only symptom that happened after the timing was changed? The fuel plate limits fuel, I have NO plate/starwheel/anything and I run cooler than you.. That stuff is more of a "governor" for fuel. They actually have NO function on the truck itself if you drive it sanely. The AFC is there only when you have less than 5psi of boost, it limits the fuel so you don't smoke up the road. After 5psi it assumes you have enough air to burn all of the fuel, so it gets pushed back, past the fuel plate, to which point the fuel plate becomes the limiter. It again is only used if you are really getting on it, but it is more there to control power so you don't burn up a stock clutch or ruin the stock automatic trans. In other words, it has no effect on everyday driving EGT's, it just stops the fueling to prevent too much power. Tell me more about the symptoms that changing the timing had.. Its really the most viable culprit at this point. I have had the timing way out of range and it had similar effects.

You would have to tell us more as to why they said the head was bad.. I have closing in on 400HP, get up to 27mpg, with 350,000 miles....If that doesn't say efficient and powerful head design, then maybe my standards are low. I do know that the 6.2 you have supposedly has the best head design ever made as far as efficiency goes, but maybe you realized those things have no power and are not exactly million mile engines. I don't think anyone can say a 12V has a bad head design though. They are known for getting great mpg as well as being capable of tremendous power. It might be true that a 12 valve has less flow than a 24 valve, but in real world tests and everything I see on the internet, there is no benefit to a 24v head unless you are a 1000HP sled puller who needs all the flow he can get.

The grid heaters come on when the air is under 60F and all temperatures below that determine how long the grid heater needs to run. So initially the grid heater is turned on based on the IAT reading which if it's been sitting all night and its 0F then that tells the grids to kick on. While they are on, the intake heats up, the IAT obviously sees this and will turn the grids off when the heat reaches a predetermined temperature. If the temperature isn't met, the grid heaters will stay on longer or maybe not even turn off and eventually throw a code. If you put the IAT in the intake tube somewhere, it will never see any kind of heating effects and the grids will initially work, but when the engine is started it will have no idea how long to leave the grid heaters on. I would think the grid heaters must be getting the air to at least 60F since they don't even come on if it is any warmer than that. So yes, bad idea.

That all sounds pretty normal but it's normal for a loaded truck... I don't understand what is loading it though. A dragging brake or something would be a very viable issue. I just can't think of what the engine could be doing to simulate perfectly what a load does to it, without there actually being a load.

Now that you mention it, I might have made something about showing it with the fuel filter housing completely removed.. That does give you a lot more room. It is easy enough to remove but can be a little bit of a hassle to remove it and the lift pump, though it does make it easier.

Jesus! and thats unloaded? That actually looks completely normal....IFFFF it had a big trailer behind it! Your numbers at 70mph sound somewhat normal but down low that is just not right. It would be something if one gauge or the other was high but when the boost is way up and the EGT is way up just going up a little hill unloaded, it means it's dumping a ton of fuel into it for some reason. Something is dragging it down causing it to work a lot harder than it should. Just to be sure though, how does it start in the morning? How does it start when it's around 30F or below? What kinda MPG does it get?

I'm not sure which video you mean. I don't know any way to make that thing easy to get to aside from getting rid of everything around it Most of my videos are unlisted so thats why you can't find them. They are listed here though http://forum.mopar1973man.com/threads/4662-List-of-Videos-for-Reference

Well if you want to check you can just take some air pressure and put it on the wastegate line that goes from the diaphragm all the way over the engine to the AFC. The diaphragm should go in and out. If you have a regulator you can set it at 20psi which is about where it should be opening. Yes that means if you aren't building 20psi, it should be shut. http://www.youtube.com/watch?v=4JXCO49H0Vk

Does it haze after it has reached operating temp? When my timing was way off it never cleared up either, unless it was at 190F.

You can also take it apart and diagnose the problem.. http://www.youtube.com/watch?v=1vFSIEL-8U8

All of your boost number sound fine. If you can hit 30psi with the fuel plate fully back then that really says your turbo and plumbing is fine. You can only hit 1000 because of that fuel plate being where it is. Let me keep thinking about this.

http://youtu.be/oELl8bcZnqo

Well I just took mine out and although it's 2wd and a 5spd, it should be close enough. But I as only seeing 550F at 2psi up a 6% grade in 4th (same as your 3rd). http://youtu.be/z60h_zGsOqU The timing thing won't be obvious, but high EGTs and crappy power are all signs. But, this is starting to sound like something else. I have gone up some 15% grades at 1200RPM in 4th and was seeing maybe 800-900F. So either that hill you were on was a lot steeper than 6% or something is wrong. You say it runs perfect though. Does it smoke anytime?

If you lug it, EGT's will go way up because the engine is not "pumping" any heat out. You are putting a lot of fuel to it to try and get it to go at 1200RPM but it is a lot happier at 1600+RPM, it isn't designed to lug that low and therefore you just dump more fuel to it and it just builds more heat than it can get rid of. 5-15psi sounds about right though. It takes a lot of fuel at low RPM to build any boost because again you aren't pumping much air or heat so you have to put in a lot of fuel to get more heat which expands the air more making it "bigger" and is then enough to drive the turbo, somewhat. I'll make a video for you today so you can compare and maybe tell me how your's is different and that will give us some clues possibly. You haven't really mentioned anything that would cause higher EGT's. Actually there is onee thing... If your timing is really retarded it will run great, but won't have the power and EGT's will soar. It would cause really good power down low but would fall on it's face up higher. I know you were seeing 1000F EGT down low but again thats just the nature of lugging it, I assume it felt like it had more power down low than the 24V and fell on its face over like 1500RPM?

Same as Mikes, 55 is typically around 400's on level ground. I do idle more in the 250 range.

Alright so I noticed the insides of my tires were wearing down a lot and the outsides were brand new.. Apparently I can't adjust camber so I went to toe. According to my calculations it was a little over 1/16" toe out on both sides or 1/8" if one side was square. I was told you want it to be just a hair under 0 or toeing in, so I set it to be at 1/16th toe in on both sides maybe even a little less. I also put the worn tires on the back since the back end always wears stuff evenly so it can wear the other side down. I went out for a drive and it didn't even think of vibrating.Now the only thing that keeps me from being sure that it was the toe or the uneven wearing or both, is that it only did it on the passenger side, making me think the tire belt thing. I think I will take the tire in and have it checked out, don't need another explosion lol.

I read and reread a million times what it said to make sure it wasn't going to format anything. It didn't even list partitions it just listed the whole drive. I never even made it do anything with that external hard drive so I don't know why it formatted it. It wasn't just 200gb of crap it was 200gb of everything I have ever had. I have been dumping everything to it from my computer because I have been playing hard drive musical chairs so the only thing on the computer drive is 20 pictures of BS, 5 BS spreadsheets, 1 BS video, and yeah, nothing. The millions of videos and pics and spreadsheets and programs and other crap is just gone. I really don't care, but I sure can't help anyone with pics anymore. I can link them to pics on here but thats it. Wouldn't care if I knew what I did to delete them.

I coulda sworn I read gas No wonder I couldn't figure out what anyone else was talking about. Seem to be misreading things a lot lately.

I just don't know when it did it. Whenever it did, it had to have just been a quick format thing. Who knows. My camera still works lol. I actually have a lot of pics on a background server on the site, but thats only maybe 10% of them, and no videos, I had tonnnnns of videos. Tons of stuff I never got around to posting. For every 1 video I have posted here I probably had 3 different versions of it that I could use in other videos depending on the view I wanted. We shall rebuild! Bigger and BETTER! lol

Well fedora says its empty too. That uhhhhh, yeah. That sucks. I guess I only lost 200GB of pictures/videos/spreadsheets :banghead: Not sure what I did, the installation of fedora had to do all that mounting crap, guess it molested that drive.

Ummmmm I'm not sureeee but I think fedora somehow wiped my entire external hard drive.. Windows says it's empty. That could be a big problem because every pic I have ever taken, every video, every excel...... You guys might be SOL on help now..