Fuel Pressure Too High Code

[Silverwolf]

High everyone. New to the forum, need some help with my 06 ISX 400. It threw a code for fuel pressure too high. (128 94 0 code) I can't figure out what would cause this, and its causeing a huge loss in power. It drives fine, runs fine and smooth, but it only has about half power. It throws the code every time I start the truck, then won't do it again until I start it again. But the power loss is all the time since the first time it threw the code. Can anyone help me figure this out. Its the only way I can move my backhoe, and I can't afford a mechanic.

[Rawze]

Go register your engine on quickserv.com for all the manuals for the engine + troubleshooting trees and breakdown of all parts. -- its free.


The fuel pressure is mechanically regulated in the IFSM (Integrated Fuel System Module).

It could be the pressure regulator failing, a wiring issue, or a bad fuel pressure sensor. I would start with the pressure sensor if it is more than a couple years old.

[Silverwolf]

Well, Ill have to buck up and pay for a manual. I tried to sign up for the Quickserv and it doesn't work. I got signed up, it sends you an email with a temp password. You have to enter the password, then it takes you to a page to change the password to what you want. After I do that, I hit enter, and the URL fails, says the site does not exist. They have a problem with there sign up. Tried to send a message, who knows if it got threw.

I would toss some parts at it , if I knew were they were. Pressure regulator and sensor shouldn't be too much. Can you tell me were they are? I think 2 of the 4 solenoids on the pump system are the regulators? The two back ones look new, the other two look to have the whole 1.1 mil miles on them. If that's the regulators, they are old. Can some one tell me were these two parts are, and I will replace them.

[hhow55]

#25 and #41 is pressure regulator valve. and the pressure sensor is #53

[Silverwolf]

Thanks, 2 regulators? , wonder which or both? Off to the parts store

[Silverwolf]

Finally got into quickserve. Password still doesn't work, but it remembered me and let me in when I opened the link. Hope it keeps me logged in since I can't seem to sign in. Thanks for all the help. I will pick up two regulators and a sensor and give them a go. I will let you all know what happens.

[Silverwolf]

Ok, Thanks for all the help guys. Went out got a fuel sensor and both regulators. 650 bucks. Ouch. Went for the fuel sensor first. Started up, ran rough for a few seconds, think it got air in there from the sensor change. Smoothed out and the code disappeared. Went for a drive and I think I have more power than before. LOL. Anyway, returned the regulators, got 400 back. Really appreciate all the help. Life saver. I will definitely will come here for advice in the future. Thanks again
Guess I should mention, the one I took out was the original!!!!! 1.1 million miles on that puppy.

[Chamberpains]

Give these a watch. They are your fuel system in detail. They will help you understand how it all works and where it is.

Part 1
https://youtu.be/HvvFElrc5ak

Part 2
https://youtu.be/_WeiDC6S8Lw

[Silverwolf]

Thanks, will watch both.