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DDlighttruck · 07-22-2017, **(Subject: 2003 ISX suggestions needed )**

2005 IH 9900i with an ISX 500 hp, 13 speed, 3 axle truck. Motor was replaced last year with an '03 model, 450 hp. I bought the truck from a friend of mine who had it probably 7-8 years, and was the one who had the motor done. I believe he said the only difference was the turbo actuator. I've been running it OTR about 6 weeks now. I am a brand new O/O, and this is the first ISX I've driven, we do have a KW with an ISX I've driven for a couple hours.

So a few things- I believe it's got some turbo cough. Sometimes when under load accelerating, usually just once, sometimes when you take your foot off the throttle to downshift, usually only once or twice.

Turbo boost drops off when pulling a hill under load. It'll go to about 30 psi, then as you're pulling drop to around 15, might go back to 30, then back to 15, sometimes it loses enough boost/rpm you have to downshift and repeat the cycle.

I had it run on the dyno on Thursday at Cummins. They said fan on it was putting down 330, fan off 350 hp. They said spec was 340 hp fan on, so it was a little low. They said the exhaust gas pressure was bouncing around while they pulled it and recommended a borescope to check the nozzle.

I didn't have time to get more work done. They say I can reflash it to 500 hp, 1650 tq stays the same. I had originally booked it in for an overhead, but they said if you're coming in for power loss, do the dyno first to see if you are actually short power. So ok I said lets dyno it.

I'm youngish and want to run hard, I want excellent fuel mileage, I want to be able to pass uphill loaded and I want it to be reliable, all which don't go hand in hand. I'm not really interested in deleting anything just yet, but I would like more balls. I don't know what turbo coughing means for turbo health, but I'm hoping for some guidance on where to either focus my energy or money. I can fix a lot myself but some I don't mind paying for. I'm still thinking an overhead should be my next step, but a turbo inspection isn't a bad idea either.

hhow55 · 07-22-2017, **(Subject: 2003 ISX suggestions needed )**

(07-22-2017 )DDlighttruck Wrote: 2005 IH 9900i with an ISX 500 hp, 13 speed, 3 axle truck. Motor was replaced last year with an '03 model, 450 hp. I bought the truck from a friend of mine who had it probably 7-8 years, and was the one who had the motor done. I believe he said the only difference was the turbo actuator. I've been running it OTR about 6 weeks now. I am a brand new O/O, and this is the first ISX I've driven, we do have a KW with an ISX I've driven for a couple hours.

So a few things- I believe it's got some turbo cough. Sometimes when under load accelerating, usually just once, sometimes when you take your foot off the throttle to downshift, usually only once or twice.

Turbo boost drops off when pulling a hill under load. It'll go to about 30 psi, then as you're pulling drop to around 15, might go back to 30, then back to 15, sometimes it loses enough boost/rpm you have to downshift and repeat the cycle.

I had it run on the dyno on Thursday at Cummins. They said fan on it was putting down 330, fan off 350 hp. They said spec was 340 hp fan on, so it was a little low. They said the exhaust gas pressure was bouncing around while they pulled it and recommended a borescope to check the nozzle.

I didn't have time to get more work done. They say I can reflash it to 500 hp, 1650 tq stays the same. I had originally booked it in for an overhead, but they said if you're coming in for power loss, do the dyno first to see if you are actually short power. So ok I said lets dyno it.

I'm youngish and want to run hard, I want excellent fuel mileage, I want to be able to pass uphill loaded and I want it to be reliable, all which don't go hand in hand. I'm not really interested in deleting anything just yet, but I would like more balls. I don't know what turbo coughing means for turbo health, but I'm hoping for some guidance on where to either focus my energy or money. I can fix a lot myself but some I don't mind paying for. I'm still thinking an overhead should be my next step, but a turbo inspection isn't a bad idea either.

First do an egr tuneup,in the video link you will find how it is done. And make sure you replace your exhaust pressure sensor, because most likely this is what is causing your turbo cough. https://www.youtube.com/watch?v=FhJxpyS5MpY

DDlighttruck · 07-22-2017, **(Subject: 2003 ISX suggestions needed )**

Will do once I'm off the road again. I'm on #2 on the tune up vids.

marek4792 · 07-22-2017, **(Subject: 2003 ISX suggestions needed )**

While doing the tune up I would go ahead and replace the two sensors on the intake manifold and there's a egr differential pressure sensor behind the electric fuel pump with two tiny pipes coming out of it and a temperature sensor on the mixer pipe.

DDlighttruck · 07-23-2017, **(Subject: 2003 ISX suggestions needed )**

(07-22-2017 )marek4792 Wrote: While doing the tune up I would go ahead and replace the two sensors on the intake manifold and there's a egr differential pressure sensor behind the electric fuel pump with two tiny pipes coming out of it and a temperature sensor on the mixer pipe.

Why? Just because, or are they common sensors to fail? So four sensors in all you would recommend replacing?

Nilao · 07-23-2017, **(Subject: 2003 ISX suggestions needed )**

I wouldn't say they fail, they plug up with soot and start giving false readings.

Hammerhead · 07-24-2017, **(Subject: 2003 ISX suggestions needed )**

(07-23-2017 )DDlighttruck Wrote: Why? Just because, or are they common sensors to fail? So four sensors in all you would recommend replacing?

Hi DD, welcome to the dark side...we will shine the light for ya...lol
An ECM is an Electronic Control Module, or "computer", and like any computer it's only as good as the information you give it, lie to it and put shi#t in, get shithouse lies out. Give it good information and it will have a good reliable output, that simple.
Sensors degrade over time, and after about 200k miles the degradation is enough that the improvements (fuel econ, power, etc.) from new sensors will easily recover the costs of the sensors.
I know you're from Ontario, so if you run south {shop name removed. no longer recommended} and shouldn't be too hard to get to for you. Your wasting your time going to Cummins. If you get out to AB, drop me a line and we'll meet up if I'm around.
As far as your driving style, around here we won't sugar coat it, if you drive hard and constantly want "more", expect to get blasted for it...
Wanting to "pass everything while going uphill" is fine when you're a brain dead company driver, but now that you own it and PAY for the REPAIRS, your new mantra is; I don't care if I'm the last one up the hill, as long as I'm the first one away from the fuel pumps and don't go to the shop for anything other than annual inspections! That's the key to success right there.

hhow55 · 07-24-2017, **(Subject: 2003 ISX suggestions needed )**

(07-24-2017 )Hammerhead Wrote:
(07-23-2017 )DDlighttruck Wrote: Why? Just because, or are they common sensors to fail? So four sensors in all you would recommend replacing?

Hi DD, welcome to the dark side...we will shine the light for ya...lol
An ECM is an Electronic Control Module, or "computer", and like any computer it's only as good as the information you give it, lie to it and put shi#t in, get shithouse lies out. Give it good information and it will have a good reliable output, that simple.
Sensors degrade over time, and after about 200k miles the degradation is enough that the improvements (fuel econ, power, etc.) from new sensors will easily recover the costs of the sensors.
I know you're from Ontario, so if you run south {shop name removed. no longer recommended} and shouldn't be too hard to get to for you. Your wasting your time going to Cummins. If you get out to AB, drop me a line and we'll meet up if I'm around.
As far as your driving style, around here we won't sugar coat it, if you drive hard and constantly want "more", expect to get blasted for it...
Wanting to "pass everything while going uphill" is fine when you're a brain dead company driver, but now that you own it and PAY for the REPAIRS, your new mantra is; I don't care if I'm the last one up the hill, as long as I'm the first one away from the fuel pumps and don't go to the shop for anything other than annual inspections! That's the key to success right there.

Well written Mr. Hammerhead

Waterloo · 07-24-2017, **(Subject: 2003 ISX suggestions needed )**

Spot on Mr Hammer, yet again! If I had a nickel... I would not be here. Truck is finally running good. Lost that fuel tank strap, got another coming for the other side... A few more maintenacne issues to take care of and my money pit will be brand new! Knock on WOOD. Oh, just traded in the wife for a new Chevy Silverado. Things are looking up around here!