ISX engine surging

[Roysbigtoys]

I have a 09' 386 Peterbilt, 485 ISX, 520k miles. About 6 months ago the mandate was removed ( a member on the forum programmed it and I did the mechanical part) and it has been running GREAT.
Today I first noticed that under acceleration it would rev freely up to 1500rpm.....then it was like a governor kicked in.....would only slowly gain speed. Gauges looked good, but the check engine light was on. It then started surging while I was holding the throttle still. The longer I drove, the less power I had.
I limped it back to my shop and will tackle it in the morning.
I finally have insite, but this will be the first time of me using by myself. What tests should I run? What else should I look for?

[Wiseman]

Where did you fuel last time ? Do you have see true filter ? If you have one , where's the level ? When did you last change your fuel filters ? Let's start with the simple things . Then check your fuel pressure. See what codes you have . It's properly programmed . It shouldn't switch in different mode itself .
To me sounds like fuel starvation. Any smoke?

[Nilao]

Agree with wiseman. Change fuel filters first. Bet you have a fuel pressure code.

[Roysbigtoys]

(07-12-2016 )Wiseman Wrote:  Where did you fuel last time ? Do you have see true filter ? If you have one , where's the level ? When did you last change your fuel filters ? Let's start with the simple things . Then check your fuel pressure. See what codes you have . It's properly programmed . It shouldn't switch in different mode itself .
To me sounds like fuel starvation. Any smoke?

I only have the factory filters....no see thru.
The filters have about 10k miles on them. I agree with you on starting with the simple things.
No smoke .......... it did a lot before the mandate was removed.

[Roysbigtoys]

Wiseman and Nilao you guys were right........ new fuel filters took care of my problem.
I have never had them slowly deteriorate like that. Usually you are running just fine and then it is like someone shut the fuel off. Thanks for the help!

[Wiseman]

Glad to hear that .
Check for algae in your thanks. Damn biodiesel.....

[simon999]

(07-13-2016 )Wiseman Wrote:  Glad to hear that .
Check for algae in your thanks. Damn biodiesel.....

Yes algae is horrible thing. My filters were clogging like every 6000miles and were black. I put some additive and next oil change black chunks fell from my fuel filter housing. Took about a month to clean everything out.

$30 paid at local marine store.

[fish hooks]

im having somewhat same issue as other driver but mine is a 2012 and I changed both filters and when im loaded and put my foot into it to clime hill manifold press hits 32 engine light comes on and I lose power till pressure drops down code 0559 fuel rail pressure ? any one help I haven't been able to fix yet

[Rawze]

(07-20-2016 )fish hooks Wrote:  im having somewhat same issue as other driver but mine is a 2012 and I changed both filters and when im loaded and put my foot into it to clime hill manifold press hits 32 engine light comes on and I lose power till pressure drops down code 0559 fuel rail pressure ? any one help I haven't been able to fix yet

Trash in the fuel lines or clogging filters?

Bad regulator or bypass valve?

Bad pump?