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race7820000 · 06-21-2018, **(Subject: N14 fuel restriction question )**

I have a 98 n14 in a freightliner, the fuel restriction gauge will go high at idle but when you give it throttle it will go down and stay down. The higher the rpm the lower it goes.

It does the exact opposite like if you have a plugged fuel filter.

Is there a return check valve or a screen or something?

It's a mechanical gauge

I changed fuel filter and took out and cleaned the check valve by the fuel inlet that runs from line by the computer to filter.

Thanks

race7820000 · 07-01-2018, **(Subject: N14 fuel restriction question )**

Found the problem lol

I'm guessing I'm going to need to clean the tanks out

hhow55 · 07-01-2018, **(Subject: N14 fuel restriction question )**

(07-01-2018 )race7820000 Wrote: Found the problem lol

I'm guessing I'm going to need to clean the tanks out

And replace all the fuel lines, and the block valve's as well.

Chamberpains · 07-02-2018, **(Subject: N14 fuel restriction question )**

If I remember correctly the fuel lines run through the ECM on a Cummins n14. I had one years ago that someone dumped cigarette butts in the fuel tanks and some of the cotton got lodged in the ECM.

hhow55 · 07-02-2018, **(Subject: N14 fuel restriction question )**

There is a fuel cooling plate, which is behind the ecm.

Chamberpains · 07-02-2018, **(Subject: N14 fuel restriction question )**

(07-02-2018 )hhow55 Wrote: There is a fuel cooling plate, which is behind the ecm.

That's right. You have to pull the ECM off then the cooling plate. Then I just blew shop air through it and a wad of mung came out.

snailexpress · 07-02-2018, **(Subject: N14 fuel restriction question )**

(07-02-2018 )Chamberpains Wrote:
(07-02-2018 )hhow55 Wrote: There is a fuel cooling plate, which is behind the ecm.

That's right. You have to pull the ECM off then the cooling plate. Then I just blew shop air through it and a wad of mung came out.

Interesting how cotton made it thru fuel filter as ECM cooling plate after filter.

07-02-2018, **(Subject: N14 fuel restriction question )**

(07-02-2018 )snailexpress Wrote:
(07-02-2018 )Chamberpains Wrote:
(07-02-2018 )hhow55 Wrote: There is a fuel cooling plate, which is behind the ecm.

That's right. You have to pull the ECM off then the cooling plate. Then I just blew shop air through it and a wad of mung came out.
Interesting how cotton made it thru fuel filter as ECM cooling plate after filter.

n14 ecm cooling plate is before filter if my memory serves me right. fuel inlet is number 9.

Unless you run some sorta fuel water separator or aftermarket thing, then there would be separator first.