Checking rail pressure while cranking

[Konstantin]

(11-11-2019 )Lonestar10 Wrote:  could be a deadspot in the sensor that it moves into and goes limp. biggest thing is that the elec is pumping fuel and that fuel pressure skyrockets above 200PSI as soon as you hit the key which means the gear pump is good. the pressure sensor is on bottom of the IFSM looks just like the exhaust back pressure sensor. its on the bottom left side just to left of fuel filter.

thanks, no it is not sensor I measured with the gauge. it also changes sound at the same time when it looses 10 psi pressure and goes to 0. I think maybe it is normal operation, or maybe pump is going out or I should have installed new gasket... In order to remove priming pump I removed a lot of stuff around it. I want to finish repair before putting everything back together.

[Konstantin]

I finally fixed the truck. I was getting furious and was checking everything... It turned out to a fuel filter gasket. When I was changing oil at a truckstop for some reason mechanic did not install small round gasket on a first filter, when I unscrew it just big gasket was there. Bummer. As soon as I addressed it everything is working fine. No more truckstops...

[Rawze]

(11-12-2019 )Konstantin Wrote:  ...
it also changes sound at the same time when it looses 10 psi pressure and goes to 0.
...

Mine does this when it is sucking air after a davco change.

Maybe air getting into the fuel somewhere?

{edit}
--- AHHH,.. I see you solved it. Thanks for sharing.

[Waterloo]

The reason I mentioned that fuel filter, it has happened to me at least twice when servicing the truck. These kids they employ just throw things together. Whenever I have had starting issues, the Davco is always the first place I go, and so far, that is where the problem has been. I carry an extra Davco with o rings in the truck just for that reason, along with my Davco Wrench. Start simple and then move up the chain...

And I know you do not have the Davco, but same principle involved with the gasket on your screw on unit, been there too, rare they mess up that filter, but it still happens, oil filters too, that is a real mess.

[Konstantin]

(11-13-2019 )Rawze Wrote:  

(11-12-2019 )Konstantin Wrote:  ...
it also changes sound at the same time when it looses 10 psi pressure and goes to 0.
...

Mine does this when it is sucking air after a davco change.

Maybe air getting into the fuel somewhere?

{edit}
--- AHHH,.. I see you solved it. Thanks for sharing.

Thanks! yes, it was sucking air. Now engine runs smooth, no surges and spikes ))))) happy

[Konstantin]

(11-13-2019 )Waterloo Wrote:  The reason I mentioned that fuel filter, it has happened to me at least twice when servicing the truck. These kids they employ just throw things together. Whenever I have had starting issues, the Davco is always the first place I go, and so far, that is where the problem has been. I carry an extra Davco with o rings in the truck just for that reason, along with my Davco Wrench. Start simple and then move up the chain...

And I know you do not have the Davco, but same principle involved with the gasket on your screw on unit, been there too, rare they mess up that filter, but it still happens, oil filters too, that is a real mess.

I had to listen to your advice sooner and I would save a lot of time, I just couldn't imagine how it is possible to install filter wrong ))) . I was not even thinking of it. How wrong I was. Is Davco filter superior to regular filter? I have Davco on dead engine, so might as well install it.

[Waterloo]

(11-13-2019 )Konstantin Wrote:  

(11-13-2019 )Waterloo Wrote:  The reason I mentioned that fuel filter, it has happened to me at least twice when servicing the truck. These kids they employ just throw things together. Whenever I have had starting issues, the Davco is always the first place I go, and so far, that is where the problem has been. I carry an extra Davco with o rings in the truck just for that reason, along with my Davco Wrench. Start simple and then move up the chain...

And I know you do not have the Davco, but same principle involved with the gasket on your screw on unit, been there too, rare they mess up that filter, but it still happens, oil filters too, that is a real mess.

I had to listen to your advice sooner and I would save a lot of time, I just couldn't imagine how it is possible to install filter wrong ))) . I was not even thinking of it. How wrong I was. Is Davco filter superior to regular filter? I have Davco on dead engine, so might as well install it.

If you have that Davco, I would install it, it is nice to actually be able to visually see what is going on with your fuel, like if the Davco bowl suddenly fills up, odds are you bought some water laden fuel, and it is nice to be able to see just that, and easily drain off when need be. And if you do install, I purchase the filters off of the internet, 10 micron, usually a few at a time and try to carry one with me along with the wrench. The filters come with new o rings, the wrench is inexpensive and can be purchased at FleetPride. The filter wrenches are plastic or metal, I like the metal ones, I think I paid around $10 for mine.

[Konstantin]

(11-13-2019 )Waterloo Wrote:  

(11-13-2019 )Konstantin Wrote:  

(11-13-2019 )Waterloo Wrote:  The reason I mentioned that fuel filter, it has happened to me at least twice when servicing the truck. These kids they employ just throw things together. Whenever I have had starting issues, the Davco is always the first place I go, and so far, that is where the problem has been. I carry an extra Davco with o rings in the truck just for that reason, along with my Davco Wrench. Start simple and then move up the chain...

And I know you do not have the Davco, but same principle involved with the gasket on your screw on unit, been there too, rare they mess up that filter, but it still happens, oil filters too, that is a real mess.

I had to listen to your advice sooner and I would save a lot of time, I just couldn't imagine how it is possible to install filter wrong ))) . I was not even thinking of it. How wrong I was. Is Davco filter superior to regular filter? I have Davco on dead engine, so might as well install it.

If you have that Davco, I would install it, it is nice to actually be able to visually see what is going on with your fuel, like if the Davco bowl suddenly fills up, odds are you bought some water laden fuel, and it is nice to be able to see just that, and easily drain off when need be. And if you do install, I purchase the filters off of the internet, 10 micron, usually a few at a time and try to carry one with me along with the wrench. The filters come with new o rings, the wrench is inexpensive and can be purchased at FleetPride. The filter wrenches are plastic or metal, I like the metal ones, I think I paid around $10 for mine.

Thanks! When I have time I would install it. And when do you change another filter? Just at regular PM? Does 2nd filter gets clogged at the same time? How to tell?

[Waterloo]

I replace every PM, but that is me... 12,000 to 16,000 miles.