Anyone with bad fuel mileage try replacing the fuel preasure pop-off valve yet?

I mentioned the rumor to my dealer and they ordered me a new valve just to see what happens.

Will let you know after it's done.

Cheers,
RH

 

Sounds like a great dealer!

Please keep us posted.

Thanks.

 

Yeah, by all means, please keep us updated... my already poor mileage is getting even worse lately @ 5K miles... back down into the mid 12's, even running empty on the hwy... this is getting really old... thinking of switching back to my gasser (which is still for sale) as it gets BETTER mileage than this thing

 

If you are talking about the "pressure limiter valve" it's not going to have any effect on mileage. Matter of fact if it leaks your truck will not run right if at all. It is a mechanical safety device that allows excessive rail psi to bleed by. Trouble is when the psi "bleeds" by were talking psi that can be in excess of 25,000 lbs. This high psi tends to actually cut the seat in the valve causing it to leak. I've replaced two of these valves on the common rail fuel systems that were running mods.

 

JBody, there was a tuner in another forum that mentioned that the pressure it was releasing at was too low for some of the valves, a manufacturing defect perhaps?

 

anyone know what this pop-off valve costs?

 

Was this discussion at TDR? I would like to read up on this theory.

 

I believe it was the Dieselram website. The first I saw was a post by Ted Jannetty. He said that they had seen or heard of some bad ones. I actually started thread over here on the subject, but it died.

Here's the thread

Neil

 

Interesting. The two I replaced were towed in and the leakage through the psi limiting valve was even noticable cranking.