Skip to main content ↑ ↓
Topic: Boost Pressure for ISL 400 with CAPS (Read 5401 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

Boost Pressure for ISL 400 with CAPS

Yahoo Message Number: 82277
There has been a lot of discussion regarding leaking charge air coolers and lack of boost pressure. I would like to know what boost pressures most owners are seeing from their engines.
I have a late 2003 ISL 400 with the CAPS fuel system. According to the folks on the Cummins hot line my waste gate is set to open at 25 pounds boost pressure. I have observed a max of 23.8. I was told that number was in the ball park and the difference between the 23.8 and max was probably a leaking waste gate. The tech said a leaking waste gate was a very common problem.
I am using my Silverleaf to get the boost numbers. I am curious what other folks are seeing for boost numbers and if their was any observed changes when the charge air cooler was replaced due to leaks or repairs to the waste gate were performed.
As a side note, a friend with a later model ISL 400 with a common rail fuel system mentioned he was seeing 34 lbs of boost. It looks to me like that maybe in error.

Norm

2004 Intrigue #11773

Re: Boost Pressure for ISL 400 with CAPS

Reply #1 –
Yahoo Message Number: 82281
Norm,

I have an ISL 400 with common rail and it's not unusual to see 34 psi at low altitudes. It doesn't stay there very long though. It will stay in the 32-33 psi range while climbing a steep grade. I also won't see these numbers at high altitudes.

Barney

07 Inspire 52059

Re: Boost Pressure for ISL 400 with CAPS

Reply #2 –
Yahoo Message Number: 82284
The last time I had my Coach on the CC dyno in Junction City the highest was 24.2 lbs, measured on

their read out and printed out for me. in the fall of 06 after the new CAC was installed, which I just

replaced this year. AGAIN.
TWI 2004 Intrigue 11731

Quote

From: fourninerpapa n.pawson@... Date: Tue, 11 Sep 2012 16:12:03 -0000 To: Country-Coach-Owners@yahoogroups.com Subject: [Country-Coach-Owners] Boost Pressure for ISL 400 with CAPS

There has been a lot of discussion regarding leaking charge air coolers and lack of boost pressure. I

would like to know what boost pressures most owners are seeing from their engines.

I have a late 2003 ISL 400 with the CAPS fuel system. According to the folks on the Cummins hot line

my waste gate is set to open at 25 pounds boost pressure. I have observed a max of 23.8. I was told

that number was in the ball park and the difference between the 23.8 and max was probably a leaking

waste gate. The tech said a leaking waste gate was a very common problem.
I am using my Silverleaf to get the boost numbers. I am curious what other folks are seeing for boost

numbers and if their was any observed changes when the charge air cooler was replaced due to leaks or

repairs to the waste gate were performed.
As a side note, a friend with a later model ISL 400 with a common rail fuel system mentioned he was

seeing 34 lbs of boost. It looks to me like that maybe in error.

Norm

2004 Intrigue #11773

mail2web LIVE ? Free email based on Microsoft® Exchange technology - https://link.mail2web.com/LIVE

Re: Boost Pressure for ISL 400 with CAPS

Reply #3 –
Yahoo Message Number: 82285
I don't have my dyno numbers with me. When we bought the coach 2 1/2 years ago with just under 13K, we paid for a full Cummins dyno and inspection.
We are at 23K now (hope to really add to those miles starting next year:)!). On our last trip out, climbing I80 West from Reno, I observed low to mid 23.x PSI range. Also on a CAPS ISL370.
One person with a SOB powered CAPS ISL370, told me he never got excited as long he was seeing high 22.x to low to mid 23.x ranges. Each engine can have it's own personality...
So far, knock on wood, no CAC problems... But we'll keep and eye out for the normal CAPS era related problems:)!

Best to all, be safe, have fun,
Smitty

04 Allure 31017
04 Allure Sold to a nice new owner! Now enjoying a 07 Magna Rembrandt 45' ISX600 #6775
"We're ONDROAD for THEJRNY!" (Toad and Coach license plates, say Hi if you see us!)

Re: Boost Pressure for ISL 400 with CAPS

Reply #4 –
Yahoo Message Number: 82286
Norm, I'll add either to knowledge or confusion. I just got off the phone with the Cummins Hot Line asking for the Boost Pressure Spec. range for an ISL 370 or 400 with CAPS

1. They advised that their spec. records only go back to 2003 with the Common Rail system which is 34 PSI. They say they do not have the spec on 2003 or earlier with CAPS.

2. However, I have spoken with John Wolf - Tech Services for Cummins Northwest who I think is the smartest Tech for Cummins particularly when installed in a Country Coach. John states spec is 23 - 25 PSI at full throttle @ 1,900RPM
3. I had my CAC repaired last October with new Boots & Clamps, which I frequently re-tighten. I am only achieving 21.9 PSI, maybe hit 22.0 PSI once in awhile. I'm now going to test for air leaks surrounding the Waste Gate hoses.

4. I did confirm today on call with Cummins that the Waste Gate for an ISL 370 is set to open at 29 PSI. I then asked if there was a problem with the Waste Gate opening to early it would throw a "Fault Code". If their were leaks in hoses it would not throw a "Fault Code".

Congrats to those of you who are achieving in the 23 to 24 PSI Range.

Thanks, Mike 03 Allure 1st Ave. #30898 ISL 370 chipped to 400

Re: Boost Pressure for ISL 400 with CAPS

Reply #5 –
Yahoo Message Number: 82293
Can't give exact numbers but 22+ is what I get on my ISL400 with caps and s new cooler Ed McManus 02 intrigue...11361

Re: Boost Pressure for ISL 400 with CAPS

Reply #6 –
Yahoo Message Number: 82305
Thank you all for your replies. It seems to me that there is a lot of variants between engines and no consensus on what boost pressure is in the ball park and what is not.
I am concluding that the low to mid 20s on a CAPS system is ok and over 30 on a common rail is system is good. I am still trying to figure out how a difference in fuel delivery can make such a big difference in boost pressures.

Norm

2004 Intrigue #11773
-

Re: Boost Pressure for ISL 400 with CAPS

Reply #7 –
Yahoo Message Number: 82307
Norm..........My 8.3 ISC tops out @ 24 PSI

Dave Trotter

01 Intrigue 11215

Re: Boost Pressure for ISL 400 with CAPS

Reply #8 –
Yahoo Message Number: 82320
Norm, They might have changed the Turbo with the Common Rail Fuel system, you could call the Cummins Hot Line @ 800 343-7357, try to get Gardner Cox he really knows his stuff.

Thanks, Mike 03 Allure 1st Ave.#30898

Re: Boost Pressure for ISL 400 with CAPS

Reply #9 –
Yahoo Message Number: 82331
Thanks for the suggestion Mike.

I would think going from mid 20s to mid 30s on boost would add lots of horsepower.

Norm

04 Intrigue #11773

Re: Boost Pressure for ISL 400 with CAPS

Reply #10 –
Yahoo Message Number: 82332
Boost parameters for all these engines are determined and built according to the specs for the engine by the manufacturer. The only way to know what the boost should be is by checking the engine specs or calling the maker and asking what it should be. Fuel system type, etc are not determining factors. In most cases the boost is controlled by the engine management system as to max boost. Also, boost is a function of engine load not RPM.

MIkee

Re: Boost Pressure for ISL 400 with CAPS

Reply #11 –
Yahoo Message Number: 82457
Friends, I would like to clarify new information regarding my note #4 below: It states that Cummins Hot Line folks say that problems with the Waste Gate on Turbo ISL 370/400 with CAPS would "throw a fault code" except if it is a leaking hose issues which it would not.
After talking with John Wolf- Technical Services Cummins NW, he advises "Waste Gate Problems" Does Not Throw A Fault Code" as it's mechanical. To confirm if "Waste Gate" is opening prematurely we'd have to have Turbo Pressure Tested to measure PSI of opening to spec or not. This isn't easy do to difficult access space to work.
I believe John Wolf, this isn't the first time I've received different opinions from the Cummins Hot Line by talking with two (2) different Tech's. Example one says Gate opens at 25 PSI another says 29 PSI.

Thanks, Mike 03 Allure 1st Ave. #30898 ISL 370 Chipped to 400

Caps or Common Rail

Reply #12 –
Yahoo Message Number: 82464
Hello, I have a 2003 Allure with a 370 Cummins. How do I determine if I have a CAPS or a Common Rail setup? What's the difference? Is one setup better then the other? Are there any on going problems with either setup? Thanks, John 03 Allure 30951

Re: Caps or Common Rail

Reply #13 –
Yahoo Message Number: 82467
John,

The common rail system does not have a waste gate valve. It uses a variable turbo that does a number of things such as controlling the boost pressure and exhaust gas recirculation internally.
Barney

07 Inspire 52059

Re: Caps or Common Rail

Reply #14 –
Yahoo Message Number: 82471
John, without trying to describe the visuals inside your engine, just call Cummins Hot Line 800-343-7357, have your Engine Ser. # handy, give to them with your question and they'll tell you whether it was manufactured with the CAPS "Cummins Accumulator Pump System" or "Common Rail", pray for Common Rail.

Thanks Mike 03 Allure 1st Ave. #30898 ISL 370 chipped to 400 CAPS

Re: Caps or Common Rail

Reply #15 –
Yahoo Message Number: 82475
Mike is right, call Cummins to confirm. The Eng Serial is usually on the sticker of info. In our 04 coach, this is on back of the bathroom mirror. (Though a typo on ours, required me to also retrieve it from the actual engine. Simple mistake by CC, and 'stuff happens':)!).
All that being said, I found our that our engine was built in July of 03, and our coach was built in Sept of 03. It is an 04 model. Our coach number is 31017, which is higher then yours, if CC did build them in actual sequence (may have different sub sequence numbers within the Allure line, for the High Cascde vs other sub models).

And, ous is the CAPS...

Caught me by surprised, as when I bought the rig off of consignment, I specifically asked the dealer's Service Department to validate it was a Common Rail. Assume an honest mistake, as the asnwer was yes it is Common Rail - believe they stated this based upon the 04 coach year.... It is what it is. And it ws 'my bad' for not doing my own validation on this...
We like the coach, but may have not paid the same price that we did if I had known it was CAPS. Would have also pushed for and 'at cost' Extended Warranty if I had known this, as a condition of purchase.
I HAVE TO DATE, HAD NO CAPS PROBLEMS. But, only put about 10K more on it in 2 1/2 years. Now at 23K, and hope to add to this quite a bit starting in 2013:)!

I also run Optilube and Cetane in each tank of fuel.
Best of luck on your rig, and enjoy it - CAPS or Common Rail, nice coaches:)! Smitty

04 Allure 31017
04 Allure Sold to a nice new owner! Now enjoying a 07 Magna Rembrandt 45' ISX600 #6775
"We're ONDROAD for THEJRNY!" (Toad and Coach license plates, say Hi if you see us!)

Re: Caps or Common Rail

Reply #16 –
Yahoo Message Number: 82476
I had the same issue. I found I had a CAPS system in my 04 Intrigue but thought I was getting the common rail system.
The folks at the Cummins hot line are most informative regarding the problems with the CAPS system.
I was told that fuel starvation was the number one cause of failure of the CAPS pump because the lift pump fails to deliver enough fuel to the high pressure pump. The lift pump failure is usually caused by dirty fuel filters plugged with algae growing in the fuel.
The CAPS pump was built in 5 modules so that each module could be repaired without replacement of the whole pump. It was explained to me that most technicians do not know how to troubleshoot the pump to the point of knowing which section to replace so you are sold a complete pump with a very high price tag. As I remember someone on this board went through that process. a sign that the lift pump is loosing it's capacity is, failure of the engine to promptly start after the lift pump has shut down. When you turn the key on you can hear the pump running. It times out after two minutes according to the tech I spoke with at the hot line. After the time out the engine should start without undue cranking over before it starts.

Norm

2004 Intrigue #11773

Re: Caps or Common Rail

Reply #17 –
Yahoo Message Number: 82482
Norm, I agree with your dirty fuel filter issue, I've checked the schematic on our Fuel Supply Line from Tank it first enters the Primary Fuel Filter then into the Lift Pump also known as Transfer Pump, then fuel enters the Secondary Fuel Filter before entering the CAPS High Pressure Fuel Pump.
The Lift Pump/Transfer Pump shuts off 1 to 2 minutes after engine starts but fuel is still passing through it as I understand, I'm looking into the possibility of installing a FASS Continous Running Transfer Pump which I know has helped many 18 wheeler rigs.
Regarding the 5 parts of the CAPS components/failures, the Cummins Insite Software along with described symptoms should tell the Tech which components of the CAPS has failed. In my case it was 1. Injection Control Valve, 2. Stator 3. Transient Suppressor, if the Transient Suppressor shorts out you lose your ECM another $1,200

Thanks, Mike 03 Allure 1st Ave. #30898 ISL 370 chipped 400 CAPS

Re: Caps or Common Rail

Reply #18 –
Yahoo Message Number: 82485
Mike, The electric pump sounds like a good idea. Do you have a part number for the Fass pump

Norm, 04 Intrigue #11773

Re: Caps or Common Rail

Reply #19 –
Yahoo Message Number: 82492
Norm, just now reviewing with my local Diesel Shop for particular pump needs. We'll let you know if I decide to do it. We have to check GPH needs and review pressures into the CAPS unit fuel hose routing etc. We also intend to verify if the the Fuel Line Schematic on drawing I discussed in earlier post matches with how CC actually ran the lines?

thanks, Mike 03 Allure 1st Ave. #30898