Cummins 2005 ISL low power AGAIN!

[Doug_E_]

What we thought was a sticking exhaust brake on our MH is now a, They don't know. The exhaust brake checked out good and functioning properly.
$515.67 later and Cummins West thinks it could be a faulty turbo.
We can start it up one time and we get full boost (35lbs.), stop for fuel and restart the engine and the boost will only go to (25 lbs.).
I asked if it could be an O2 sensor or an EGR valve, they don't think so.
Would just like it fixed so we can have the reliability back again.

Now they want to put it on the dyno and see if it will give low boost while it's hooked up to the dyno.

[redguard]

JimM68 wrote:
Odd thread. My understanding has always been that ISC's will normally run 35 psi boost, but ISL's are between 25 and 30, mostly 25....

A ISC from the factory will NOT have 35 lbs boost It has around 29-31 MAX and ISL have as high as 37lbs

[redguard]

Ivylog wrote:
I have a 03 ISL and 23-24 is all it 's ever done. Plenty of power and I'm on the heavy side.

I believe you have more boost than you think>??

ISL 425HP has 35-37 lbs boost max

ISC 350HP Has 30-31 lbs Boost max

these are documented facts

[Ivylog]

I have a 03 ISL and 23-24 is all it 's ever done. Plenty of power and I'm on the heavy side.

[JimM68]

Odd thread. My understanding has always been that ISC's will normally run 35 psi boost, but ISL's are between 25 and 30, mostly 25....

[Lar_s]

Just a thought, but look at my year long saga on low power. It turnes out it was the sensor telling the engine it was at higher elevation than the flat lander's we are and would detent the fuel.

[jamesa403]

Have they checked the Low Pressure fuel pump. On mine, that would work, then lose the boost because the fuel pump wasn't working properly. The fact that it will do it after stopping for fuel makes me wonder about this.

[DSDP_Don]

Hershey.....I think "jamesa403" may have miss typed some numbers. First, I've never heard of a 300HP ISL. There have been 370, 400 and 425 ISL's. His turbo boost number is also waaaay off. Most of the ISL's are doing about 29-31 psi.

[hershey]

jamesa403 wrote:
My 2006 ISL 300 HP Cummins lost power, and what it turned out to be is the low pressure fuel pump. Prior to that there was no power and lots of black smoke. Replaced the pump and now 50 lbs of boost

I had exactly the same problem and same fix. But: Please tell us where you got that turbo? Name and info please. My ISL has to be running perfectly to get 24 lbs.
I don't know if my system could handle 50 lbs of boost but it would be nice to try.

[shanwick]

Doug E. wrote:
shanwick: How did they fix this problem? New turbo or were they able to fix the original turbo?

The coach was at Cummins Coach Care in Elkhart, and still under the original warantee. Cummins said that the actuator was hanging up due to "rust buildup" on the actuator arm, and declined to fix it, saying a new turbo was needed. The mechanic said that Cummins wouldn't or doesn't sell a repair kit for the actuator, but he found a rebuilt unit (rebuilt by Cummins) and installed it. Cummins did pay for this fix. It has ran well ever since.

The symptoms were low power, slow acceleration, some black smoke on acceleration, very noticeable fuel mileage drop, and low boost until up to highway speed. This all occured with less than 10K miles on a new motorhome.

[jamesa403]

My 2006 ISL 300 HP Cummins lost power, and what it turned out to be is the low pressure fuel pump. Prior to that there was no power and lots of black smoke. Replaced the pump and now 50 lbs of boost

[wny_pat1]

Doug E. wrote:
Has someone from RV.net used Coach Care in Bakersfield?
If so with what results?

http://rvservicereviews.com/ReviewDetails.asp?Submit=&FacilityID=1604&State=CA&Search=&CategoryID=

[Doug_E_]

Has someone from RV.net used Coach Care in Bakersfield?
If so with what results?

[Doug_E_]

shanwick: How did they fix this problem? New turbo or were they able to fix the original turbo?

[shanwick]

I had somewhat the same problem a few years ago on my 2007 ISL 400. It was slow going from a dead stop, and there was some black smoke. The problem was the actuator for the VGT turbo was sticking.

[Doug_E_]

Larry, No offence taken, I really didn't know when Cummins started offering the VGT turbo.

Thanks Steve for the info on when the change over started to occur.