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Topic: 2002 ISL Boost psi (Read 875 times) previous topic - next topic

2002 ISL Boost psi

Anyone happen to know the normal boost operating range for a 2002 ISL 400. Coach seems sluggish. Neve exceeds 19 psi on long pulls or anytime outside temps below 50 deg at 2000 to 6000 feet elevation
Thanks Scott

Re: 2002 ISL Boost psi

Reply #1
That is a little on the low side.

But for the absolute FACTS, call Cummins with your engine serial number:

Cummins 800-286-6467

Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: 2002 ISL Boost psi

Reply #2
Do you have a CUPS fuel system? I would expect about 30 psi at lower altitudes.

Starting at the most likely is the fuel supply. Lift pump pressure, filters, return to tank valve, air leak. Exhaust manifold crack or leak. Then air restriction. How about a waste gate sticking? Any codes present? Intercooler leaks, cracks? Engine timing, Turbo damage.

Since you work on aircraft and their turbos, you probably have it all down but thought I would mention the obvious.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: 2002 ISL Boost psi

Reply #3
This is my neighbors coach and I don't drive very much. Will look into after the weekend . Thanks

Re: 2002 ISL Boost psi

Reply #4
Coach seems normal except it does run like a 450. Filters all current. Certainly not a go home issue, just curious
Thanks Scott

Re: 2002 ISL Boost psi

Reply #5
Our Cat 3176B runs 28Lbs of boost.under load.
Hans & Marjet
1995 U300 "Ben" (#4719)
3176B Cat,4060HD,Jake
SKP#139131
Motorcade#17579
2006 Honda Element (towed)

Re: 2002 ISL Boost psi

Reply #6
On the non variable geometry ISL turbo, the turbo waste gate is supposed to open at 20 psi.  If I remember correctly, on full throttle, I will see 23 or 24 psi.  I would check the wastegate  and see if it is opening prematurely.  Take off the airline going to the actuator and apply about 17 or 18 psi and see if actuator moves.  If it does then you need a new actuator.  If it doesn't then you may have a leak somewhere after the turbo most likely at the CAC (charged air cooler).
2002 36' U270 Foretravel

Re: 2002 ISL Boost psi

Reply #7
what does the radiator look like? mine had fin rot and When I replaced the radiator I pressure checked CAC and fount it had several leaks that couldn't be patched so I had to replace it also.
Chris
1999 U 320 DGFE
Build Number 5523
Chris & Elka Lang
In the field, Lonoke AR


Re: 2002 ISL Boost psi

Reply #9
Made it home no issues. Boost never exceeded 19 and generally maxed at 17. I had visually inspected CAC about a year ago. Will check actuator for full travel and if okay will plug air filter housing outlet and engine inlet and pressure check to 20 psi and look for leaks. Should have a better idea after that. Great weekend at the King of the Hammers. Drove about 16 miles on groomed dirt road. Slow going. Not as many spectators as last year do to COVID. Still haven't figured out what normal operating boost Pressure is for a 2002 ISL400. Will search more in coming week.
Thanks for the insight, Scott

Re: 2002 ISL Boost psi

Reply #10
Was a volunteer at KOH a couple years ago. Had a blast. They have a circuit race at our home park in Oklahoma ( Clash at Crossbar). We hosted the Nationals back in October this year. Watched the live feed this year, after 2 weeks in the desert boon docking that was enough. Lol

I have a 2005 ISL400, my boost Max's out at 29-30. But I replaced my CAC a couple years ago.
Dave & Danette
2005 Foretravel U270, 3620 PBLW, Build #6331
2018 Jeep Grand Cherokee
2017 Can-Am Maverick X3 RR
2016 Polaris Turbo RZR
Motorcade #17839

Re: 2002 ISL Boost psi

Reply #11
Was a volunteer at KOH a couple years ago. Had a blast. They have a circuit race at our home park in Oklahoma ( Clash at Crossbar). We hosted the Nationals back in October this year. Watched the live feed this year, after 2 weeks in the desert boon docking that was enough. Lol

I have a 2005 ISL400, my boost Max's out at 29-30. But I replaced my CAC a couple years ago.
Will start sorting it out this week. Too many irons in the fire. This is helpful. Will work wastegate first and follow up with intake system till it's resolved.
"KOH" all I can say is I don't have a spending problem I have a earning problem. They are many many levels out of my affordable reach. One can dream. 125-650k for a off-road toy is crazy.
Thanks Scott

Re: 2002 ISL Boost psi

Reply #12
Was a volunteer at KOH a couple years ago. Had a blast. They have a circuit race at our home park in Oklahoma ( Clash at Crossbar). We hosted the Nationals back in October this year. Watched the live feed this year, after 2 weeks in the desert boon docking that was enough. Lol

I have a 2005 ISL400, my boost Max's out at 29-30. But I replaced my CAC a couple years ago.

In 2004/2005 Cummins went to a variable geometry turbo which increased the boost.  The OP doesn't have a Variable Geometry turbo, so he will not reach your amount turbo boost.  His wastegate is set to open at 20 psi, so he will not get much over 20 if everything is working correctly.  He definitely should be getting at least 20 psi boost. 
2002 36' U270 Foretravel

Re: 2002 ISL Boost psi

Reply #13
Will start sorting it out this week. Too many irons in the fire. This is helpful. Will work wastegate first and follow up with intake system till it's resolved.
"KOH" all I can say is I don't have a spending problem I have a earning problem. They are many many levels out of my affordable reach. One can dream. 125-650k for a off-road toy is crazy.
Thanks Scott

You can always run in the UTV class.
Dave & Danette
2005 Foretravel U270, 3620 PBLW, Build #6331
2018 Jeep Grand Cherokee
2017 Can-Am Maverick X3 RR
2016 Polaris Turbo RZR
Motorcade #17839

Re: 2002 ISL Boost psi

Reply #14
This is a Tech Talk topic attempting to assist with a technical question/issue.  Let's please keep the discussion to 2002 ISL Boost psi.

Further off-topic discussion should go in a new topic in Fire Ring, please.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: 2002 ISL Boost psi

Reply #15
Found a small leak that is probably causing low power. Can't believe it made as much boost as it did. Hose at cast 90 deg off turbo going to 4 inch. Will test drive to see if it resolves problem.
Scott

Re: 2002 ISL Boost psi

Reply #16
Yup, that would sure to it.

Good work tracing it down.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: 2002 ISL Boost psi

Reply #17
It's nice when the fix is easy and cheap.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: 2002 ISL Boost psi

Reply #18
Wonder if a silicone hose that size is available?

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: 2002 ISL Boost psi

Reply #19
Wonder if a silicone hose that size is available?

Pierce

Check here: http://flexfab.com/uploads/documents/Flexfab-Product-Catalog.pdf

CAC hoses page 26-33.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: 2002 ISL Boost psi

Reply #20
Pierce
Yes many really good hoses and upgraded spring clamps available relatively cheap. Haven't looked yet but will at end of the day after I'm finished for today on my Foretravel distraction
Scott

Re: 2002 ISL Boost psi

Reply #21
Follow up to finding bad intake hose. Ordered new hose. Cut damaged area off old hose and reinstalled. Ran down to Hoover dam and pulled 23lbs of boost up from 19 psi prior. This is a waste gate turbo so 22-24 is normal range. Coach pulls much harder and is more spry to drive. We think this has been damaged since he bought a year ago. Probably a million cubic feet of compressed intake air leaked. Glad it's behind him. Thanks for all the roadside help once again.
Scott

 

Re: 2002 ISL Boost psi

Reply #22
Brett, thank you for the link to Flexfab. Found it at Finditparts. Glad I was able to find the burnt hose. The PO had plugged the pressure hose to the wastegate valve then gave up the hunt. I had no experience with diesel engines until this purchase. On my way home 1200 miles it just didn't live up to the hype of a 400 ISL. Anxious for next trip to shakedown. Going to play with wastegate rod for a few more lbs of boost. This has brought down EGT from 1400 to 1200, I like that. I'll post findings. Jim.   
Jim and Dona
2002 U295 36'
Lily, blue healer. Our fury person
Manx mid travel Ecotec turbo
2022 Bronco badlands Sasquatch
Trail 90 and 110cc