Community Forums

Theturboman · 05-03-2023, 08:49 AM

I know this discussion has been had many times on the internet but do you guys know what boost we should see on a 2002 ISL 400. I am seeing 23-24lbs just seemed last time out felt a little sluggish and was thinking I had seen 34-35 in the past just not sure but could be my imagination. I have seen lots of talk about cracked manifolds, guessing boost drops pretty good when this happens

Jeep401 · 05-03-2023, 09:00 AM

34 35 stock I think is high. I get 28 pulling a 8000# trailer over my local mountain pass. 2005 ISL400.

Bruce Anthon · 05-03-2023, 10:06 AM

Mine reads 27-29 on hard pulls with new turbo to stock specifications. I have a 2003 ISL 400

c_oneil · 05-03-2023, 12:23 PM

I think Cummins changed the ISL to a VGT turbo the same time they went to the common rail fuel system in ‘04 engine?? Earlier years turbo boost was lower. My VGT and common rail engine the turbo peaks at 32-33 psi.

Theturboman · 05-03-2023, 07:31 PM

After a lot more reading on the internet it looks like the early ISL puts out 23-24 lbs so I feel better. The coach usually is very impressive on power while towing. I will just pay more attention next trip-- thanks for the replies

Sideshow · 05-04-2023, 05:18 PM

Bruce,
What are you using to read Boost?
Silver leaf or a scanner
Cheers

Old Scout · 05-04-2023, 06:01 PM

What Carter said--23-24 on an older, non-VGT turbo Alpine. So time to check fuel filters, or check the lift pump gasket for leaks [cold--fuel leaks out, while running--air leaks in].
PS--Bruce what "special sauce" are you using to get 27-28? [smile]

Bruce Anthon · 05-04-2023, 09:55 PM

No sauce, that is the reading from memory that I got on my BlueFire. I will take it for a run when I get back in two weeks to recheck.

Theturboman · 05-10-2023, 07:48 PM

Quote:

Originally Posted by Sideshow

Bruce,
What are you using to read Boost?
Silver leaf or a scanner
Cheers

I am just using Bluefire to watch the live boost

Bruce Anthon · 05-11-2023, 06:43 AM

I use the BlueFire on longer trips. I like to see the trans temp as well since my 03 doesn’t have a dash gauge for it.

Jeep401 · 05-21-2023, 05:19 PM

Ok, so I took a short trip this week, a little over 400 miles. As it turns out I am actually getting 32 pounds pretty regularly while climbing the pass and saw 33 a couple of times.
I must have been thinking about my Duramax when I was thinking I was only getting about 28.

Hayduke · 06-07-2023, 10:59 AM

Interesting thread

Thanks for the reminder about Bluefire.
Mine is still plugged in, but I've not used it in way too long.

It would have been useful on the recent drive to WA.
Almost here, I could feel a loss of power.
It was the 'elbow hose' from the turbo had failed, again...
In hindsight, I should have looked in Bluefire.

I'm curious what my boost is now.

Theturboman · 06-08-2023, 08:00 AM

Quote:

Originally Posted by Hayduke

Interesting thread

Thanks for the reminder about Bluefire.
Mine is still plugged in, but I've not used it in way too long.

It would have been useful on the recent drive to WA.
Almost here, I could feel a loss of power.
It was the 'elbow hose' from the turbo had failed, again...
In hindsight, I should have looked in Bluefire.

I'm curious what my boost is now.

My engine batteries died I forgot to turn the switch off so when I went to restart with the boost switch my dash gauges didnt work. I decided I would get the Bluefire computer out to see if it was a "can" signal problem or something different. Needless to say the Bluefire didnt connect so I unpluged it and the gauges started working again, plugged it back in and nothing. I contacted Bluefire (it took a few days but they replied email) and I sent it in through their email paperwork and a $20 charge and return shipping. Got an email yesterday it was on the way back. They dont make the 6 pin anymore so I was crossing my fingers it could be fixed. I emailed back asking what went wrong and no reply. They dont even have a phone number listed to call but hey as long as its fixed !!