Fuel pressure when cold out

[mdlowry]

Since it has been getting cold out here recently, I've noticed that my fuel pressure (post filter) is low (3-4psi) right after starting when the temperature is below about 40F. After a few minutes when the truck warms up the pressure comes back up to normal. I changed the fuel filter a little while ago and it didn't make a difference. I'm assuming that the fuel I'm getting up here is starting to be winterized, but I did add a cold weather addative and even that didn't seem to make a difference. Is this just the temperature? Has anyone else noticed anything like this?

Michael

 

[DEZLPWR]

I noticed the same thing....

Mine only shows 1-2 psi less vs. your 3-4. I'm puzzled as well.



Steve

 

[ROADWARRIOR]

I notice a 2 psi loss pre filter with the cooler temps. Takes about fifteen minutes for mine to warm up. Just assumed it is normal.

 

[John]

..... same here, no big deal.

 

[Steve Campbell]

Similar results I made a "cold shield" for my fuel filter out of some 3/4 inch thick cab insulation for a JohnDeere tractor. I formed it into a "U" shape and surrounded the filter leaving only the engine side open. My theory here is that it should help prevent fuel geling somewhat. I take it off for summer operation.

 

[mdlowry]

Re: I noticed the same thing....

Originally posted by DEZLPWR
Mine only shows 1-2 psi less vs. your 3-4. I'm puzzled as well.

Steve

It's not 3-4 less. It's 3-4PSI as opposed to the normal 10psi at idle. If I try driving with this, I can easily pull it down to 0psi.

Michael

 

[Bigsaint]

I notice the same 1-2 psi drop at start up when cold. If your intake/ grid heaters are cycling, they will be helping to draw down the psi's, at least they do with the Mallory.



Michael, I'd be concerned if my psi's were dropping that low as well, what do you see at idle when it's warm ?



Scott W.

 

[mdlowry]

Originally posted by Bigsaint
Michael, I'd be concerned if my psi's were dropping that low as well, what do you see at idle when it's warm ?

Scott W.

When the truck is warm I see 10-10. 5psi. I have also noticed that the fuel pressure does drop a little when the grid heaters cycle on, but pressure is still about the same (3-4).

I'm just assuming that I'm getting straight #2 for now.

Michael

 

[Patriot Diesel]

Me too !! 1-2 psi drop when cold... no big deal !!