New head, new tune, now no boost

[Svohlin1]

I’m having some trouble with a de-mandated cm871 in an 08 Peterbilt that has kinda been a problem child for years. Truck was bought at an auction about 10 years ago already de-mandated and ran great, but i guess it’s always had problems keeping heads on it, and it’s gone through the original engine and is currently on a cummins recon engine. I’ve only been around it about 6 months, 6 months ago I put a head gasket on it, and just about 2 weeks ago it cracked the head. We decided to get the ecm re-tuned since it hasn’t been since purchase and we suspect the tune to be too hard on the engine.. After replacing the head, front bank timing actuator(actuator was replaced due to a white smoke haze at idle that followed to the rear bank when swapped around) and a leaking CAC, truck still makes very low boost, like the VGT isn’t doing anything. We called our tuning company and told them what was up, turned out they loaded a non-vgt tune onto our ecm. They logged in remotely and put the proper tune on, but it still seems to be doing the same thing. I’ve had the VGT apart, it sweeps side to side freely, the actuator calibrated and installed properly, and I can hear it sweep back and forth on a key cycle like it’s moving properly. I pulled the valve cover and ran back through my overhead just to double check, it’s all perfectly in spec still. I’m starting to lean towards our tuning still being messed up. VGT position on instie moves with the throttle, commanded and actual stay very close if not even the whole time. Driving it ripping through the gears full throttle it won’t top 17lbs of boost, throws a good bit of black smoke, and upon opening the hood after a short drive you can tell the exhaust and turbo are getting much hotter than they should be.

Anyone have any insight into what else I can look at? I’m gonna get back into contact with tuning but I know they at least loaded a different calibration in, because before when unplugging the EBP sensor I would not set a code, and now it does. That’s how they had us check to see if they gave us the wrong tuning.

[tree98]

You are using very bad tunes plain and simple!!!! That will crack heads and cause boost problems all day long because those idiots don't know what the hell they are doing.Some of the statements you made are just loaded with red flags. There are only a hand full of people you can trust to tune an isx properly and they are found right here on this forum. Lately guys like you have found there way to this forum and then they want to argue with everyone about how the tune they are using can't be the problem, it's always something else. The best program ever written for the 871 is actually FREE for anyone who knows where to look for it. Are you hell bent on having 1,000 h.p. or do you just want a good reliable engine? Because you can't have both. Another reason your having these problems is because you probably didn't counterbore your block and shim your liners up to .014, doing this is non negotiable for a long lasting reliable isx. Also head bolts must be torqued properly.This forum is the best place in the world to get information about the isx, but you have to be willing to listen.

[Svohlin1]

The company we used has tuned trucks for us before, but I don’t believe they’ve ever done an isx, always had good luck with them until now it seems. Engine is originally a 550, just wanted a tune for 600 and 2050 torque de-mandated, we believe the older tuning is what was causing the head problems but can’t say for sure. The engine is a reman but if we don’t boot it to the auction house before it needs an overhaul again I’m definitely gonna follow what I’ve read on this forum, definitely some good advice. I’m gonna get ahold of them again and see if they can fix anything and if not then demand a refund and go elsewhere for tuning.

[Waterloo]

Bad tune dude... Time to wake up.

[tree98]

Don't ask them to fix it. Don't let them back inside your ecm. Consider it a learning experience and move on. Send a pm to Unilevers, mommaburt, or running rough. They'll get it right with there eyes closed.

[Rawze]

The ISX only give these kinds of problems like head gaskets, dropped liners, and the things you describe as repeating failures when they are tortured and abused. - That abuse comes in the form of bad programming, and bad/inadequate repair practices, plain and simple.


That story of pure engine torture and terror, bad programming, followed by even more bad programming is not even remotely funny. -- yet it is seen a hundred times a year on here. Welcome to the bad delete club! -- Your education starts here...

http://rawze.com/forums/showthread.php?t...5#pid13255

There are proper ways to do these things ... sounds like you have been caught up in all the wrong ways, then doing even more bad things and letting others butcher and half-arsse fix your engine .. the ISX cannot handle half-arsed repair methods or under-educated mechanics, and it sounds so far like you have been doing nothing but taking the word of these gaggle of idiots with wreches (and laptops) so far.

** START by taking your problems into your own hands .. GET yourself an inline-6 adapter off e-bay for a few hundred bucks ... learn how to use it. Learn how to pull the program out of that thing. -- the software is all over the internet for that engine for free ... The de-mandate overlay, in fact the best one on the planet for that model engine is also free ... even has instructions on how to do yourself.. .. stop letting garbage-can tuners near it... stop relying on mechanics that do not know squat about an ISX wrench on it .. and turn your problems around.

It is not your engine (or the other engine you had before) That has been your problem ... it is all the bad decisions and bad people you have let get near it and work on it so far. -- this should be your wake-up call towards getting as far away from those types of people and those ways of thinking as you can. Otherwise you are not going to be any further ahead, but only continue to suffer more problems.

[smorgan87]

Stop letting hack job so called tuners jack with ur engine and you will see the heads stop cracking. Prty simple stuff really. Isx engines arent some kinda boogy man of motors u just cant tune em to tear themselves apart and expect em to last. But i suppose u could be one of thousands of Cummins owners that put some bs in the ecm and act like cummins did something wrong because it comes apart every 5 minutes.

[Rawze]

ALSo .. the ISX does not loose head gaskets without it dropping a liner. - AND... if it drops a liner ... it always does damage to the bottom side of the head (an example: http://rawze.com/forums/showthread.php?t...48#pid7648 ). This means if you loose a head gasket, you have to counter-bore it, plus RAISE THE LINERS to fix it AND replace the head with a new one. -- EVERY SINGLE TIME ... Anything less and your doing nothing buit pissing up-wind.

What you describe not only sounds like bad de-mandate programming and butchering...but also your problems with it are not likely nearly over yet if someone did not take the time to fix it the right ways when they had the head off it. -- This is clearly a recipe for repeating disaster and clearly people who have no business working on ISX engines.

How much you want to bet that if I owned it, I could build that engine to last a million miles, it fully de-mandated, it have the original VGT turbo on it, it programmed for 600HP too. <- I am just a driver, not a mechanic...It is because I follow all proper procedures and recommendations for the engine, and do not deviate from them.

Also ... how is the thing being driven?--- What rpm ranges do you use most of the time? -- What loads and type of trucking operations? -- What tranny and rear ratios of the truck? -- For all anyone on here knows,.. you could be abusing the thing badly just by the gearing and the way it is driven too. - More info would be helpful towards your plight, and also help you to better understand your equipment instead of letting it get tortured to death repeatedly.

your story sounds like this scenario...
http://rawze.com/forums/showthread.php?t...5#pid41315

see it all the time around here.
------

to your orig question ... Get yourself an inline-6 adapter and an old laptop.. you own a modern engine, get the stuff to properly diagnose and work in it to some meduim extent. -- Get the software to pull the program out of your ecm (it is free and all over the internet) and e-mail a copy of your program it to me for review and inspection of accuracy/stability. -- Until you do this, no one will be able to help you with your turbo or other engine issues. - For all you know, the damn thing might be trying to go into an engine mode that it is not supposed to go into causing the turbo and engine to do things it is not supposed to do. This is the most common problem with these clowns who do horrible programming. This problem alone can make one crack heads, melt pistons, or take out liners (head gaskets) in a hurry. -- Sad part is that they all talk a good game but reality is that more than 90+% of shops/ppl doing delete programming out there are BAD.. REALLY REALLY BAD!!!>>>. - Bad delete programs are notorious for this. Until you can get something that is 100% known to be reliable and stable, your wasting your time trying do do anything else with it.

How much you want to bet that whoever 'tuned it' cannot even tell you the proper engine modes the engine should be operating in after such programming... how much you want to bet they likely do not even know how many operating engine modes there are in an ISX.. most of them are so incredibly clueless that it is not even remotely funny. -- How much you want to bet the idiot tells you something like 'we leave that same as factory' because they are really that stupid!. Ask em what the proper fuel-air-mix is for the ISX... what the proper injection timing should be at a given rpm and torque?-- you are not going to get any kind of actual asnwer aside form a bunch of bulls#it excuses .. BECAUSE THEY HAVE NO CLUE!!!-- THEY COPIED WHAT THEY SHOVED INTO YOUR ENGINE BLINDLY FROM SOME OTHER IDIOT WHO DOES NOT KNOW EITHER! -- this is the nightmare you have gotten yourself into and are now suffering the consequences of.

http://rawze.com/forums/showthread.php?t...0#pid16780

http://rawze.com/forums/showthread.php?t...8#pid15548

http://rawze.com/forums/showthread.php?t...5#pid15155

and on and on it goes if someone wants to know the actual truth.

====

NEXT, you should pressurize the whole engine. block plate at the intake of the turbo, and one at the outlet/exhaust of turbo, both sides blocked off. then pressurize the whole enigne up wioth 30-40psi of air pressure and find every single air leak there is in the intake, CAC, boots, pipes, air compressor, and egr circuits that may still be connected, exhaust manifold, etc.etc... whole engine ... and fix anything that leaks even slightly. - Bad programming aside, if there are leaks, they need to be fixed.

[AussieISX]

Could be off track but worth asking, did you take the big Allen head plug out of your old head and put back into the new head ? In under the ecm . It’s a port for the compressor used on the cm570