ISX450.......unrealistic expectations?

[Lonestar10]

If it came still governed at 63 it probably has a custom tune from the company that owned it that is defueling above 63.

May need a stock Cummins tune flashed into it.

Things that would help to know

What is boost doing at 63 is she screaming trying to make power? If it has a boost gauge should be hitting 30-32psi at full chooch.

Needs an EGR tune-up exh gas/IMAP/EGR diff sensors replaced.

Sure others will TuneIn with more information

[Moose]

450/1650 with the proper gearing is more than enough to run the weights you describe at 70 comfortably and should be getting 5.5-6.5mpg even mandated. IMO it's one of the better ratings for this engine. As stated above either you have something mechanically wrong on the engine, EGR and aftertreatment or it is staying in a silent derate because it sees something it doesn't like.

I haul aggregates grossing 90k typical but sometimes over and I had no problems with mine doing that. You need to decide if you want to leave the mandate intact or remove it then move forward with repairs.

[Rawze]

egr tune-up.

pressurize entire engine and fix leaks.

inspection of exhaust and dsecomp tube for restrictions. - your symptoms of weak power and hard to get past a certtian power sounds exactly like intake or exhaust restrictions somewhere.
here is one good example - http://rawze.com/forums/showthread.php?t...07#pid1807

boost and pyro gauges A.S.A.P. -- every truck should have them.

remove, take pictures of DOC, DPF, and face of SCR. Have DOC and DPF baked, de-ashed, and flow tested.


Check ecm for any fuel related codes.

Inspect the fuel pump and REPLACE THE GUTS OF THE FUEL PUMP A.S.A.P. if it has more then 400k miles on the components. Those common rail ISX fuel pumps, when they start going bad will destroy the entire engine and the only symptom will usually be a bit of power loss or low fuel pressure codes.

[smorgan87]

Ive pulled 100k with a 450hp isx, 3.36 gears and 10 speed manual. Im confident once everything is workin properly urs can handle 85k.

[Soulreaver0102]

Make you wonder if maybe they only changed cruise control speed limiter? Never know anymore with the shops now. Lol

[Mattman]

450/1650 with a 13 speed and 3.36 gears.
Never did shift into 13th. 12 gear pulled 60 to 65 mph just fine on flat ground. About 15psi of boost. Fuel mileage was like 5.7.

Hills would pull me way down. Climbing bridge on I-10 going east into Baton Rouge was one major slow down.

[hhow55]

My, My such a small world. I use to pull a lot of hcl, and caustic out of that plant when it was basf.

[Mattman]

(11-08-2019 )hhow55 Wrote:  My, My such a small world. I use to pull a lot of hcl, and caustic out of that plant when it was basf.

What plant are you referring to? The one in my picture is in South Arkansas. The only product this plant produces is Bromine. They do use caustic for the scrubber. Use HCL but not really sure why, more as a cleaner agent I believe.

[Golfnut]

Today I pulled out the Delta-P sensor and the IMAP sensor. Both are covered and plugged with soot so it looks like I'll be learning how to do an EGR Tuneup. I see most of Rawze's videos are for an 871. Are there any good resources for a CM2350?