ISX sudden boost psi change

[Rawze]

(09-21-2022 )Carter Wrote:  It probably is a particular mode it’s in at the time. I can get full rpm and boost if I want. Maybe I’m driving incorrectly. I just give enough throttle to get 10 lbs of boost let the rpm’s climb then grab the next gear and do it over again. In top gear I do the same and if I can hold 62mph at 10 lbs that’s the speed in run if I can only hold 54 mph at 10 lbs then that’s the speed I run. On flat ground at least.

bad delta-p and/or clogged imap sensor can do things like that too. When is the last time it has a full ERG tune-up?.

[Carter]

I’m thinking never. The imap sensor looks original (red paint) never tampered with. I could speak with the fleet manager, he would tell me what’s been done to this truck. Not sure he would do anything more until there’s an actual “failure” of something.

[Carter]

After reading all the information on this site, I’ve thought about doing an egr tuneup myself. We are allowed to fix things on our trucks that we can do ourselves, But, I have to tread lightly when it comes to spending money on account.
Thank you to everyone on this site for all their help and information. I will see what I can do for this particular truck and problem in the coming months.

[Rawze]

(09-22-2022 )Carter Wrote:  After reading all the information on this site, I’ve thought about doing an egr tuneup myself. We are allowed to fix things on our trucks that we can do ourselves, But, I have to tread lightly when it comes to spending money on account.
Thank you to everyone on this site for all their help and information. I will see what I can do for this particular truck and problem in the coming months.

It sounds to me like the typical neglected, poorly-spec'd truck.. then everyone wonders why it does not run right + the engine only lasting half as long from being lugged to an agonizing death all in the name of "fuel savings".

[Carter]

(09-22-2022 )Rawze Wrote:  

(09-22-2022 )Carter Wrote:  After reading all the information on this site, I’ve thought about doing an egr tuneup myself. We are allowed to fix things on our trucks that we can do ourselves, But, I have to tread lightly when it comes to spending money on account.
Thank you to everyone on this site for all their help and information. I will see what I can do for this particular truck and problem in the coming months.

It sounds to me like the typical neglected, poorly-spec'd truck.. then everyone wonders why it does not run right.

So true. What does someone in this situation do? I’m governed at 1600 rpm in all gears but 8th which will reach 1800 rpm. As long as I keep my boost down and its gaining rpm after each shift even though too low of an rpm am I doing any good?

[Rawze]

(09-22-2022 )Carter Wrote:  ...
So true. What does someone in this situation do? I’m governed at 1600 rpm in all gears but 8th which will reach 1800 rpm. As long as I keep my boost down and its gaining rpm after each shift even though too low of an rpm am I doing any good?

not much if you don't own it, except to learn how NOT to spec and own a truck.

[Carter]

(09-22-2022 )Rawze Wrote:  

(09-22-2022 )Carter Wrote:  ...
So true. What does someone in this situation do? I’m governed at 1600 rpm in all gears but 8th which will reach 1800 rpm. As long as I keep my boost down and its gaining rpm after each shift even though too low of an rpm am I doing any good?

not much if you don't own it, except to learn how NOT to spec and own a truck.

If you don’t mind me asking, how would you spec a truck for this kind of work? Optimal cruising rpm at 60 mph? And all things being equal is there a fuel mileage advantage to a 13/18 speed compared to a 10 speed?

[Carter]

Never mind I found the answer in another thread.

[Bengy88]

There is tons of information on the forum about optimal specs for nearly any application. Hell there is tons of information on here about almost any issue that anyone can have with a truck…. Just gotta dig a lil bit sometimes