2nd Gen Non-Engine/Transmission What next?

[SMcGrady]

So, as my Sig suggests, I have an Airdog FP100 installed on my truck. I think I put it it back in 2009 and everything has been just great. always 15-17psi indicated and truck runs perfect... . Then a week ago, I noticed the FP was down to about 10psi. it stayed pretty steady there and I though, time for a new filter. Well, I didn't jump right on that and now a week later my pressure suddenly drops to 3-5psi. Not throwing a code yet. So I didi mao'd over and got myself a new filter and swapped them out. Problem solved, right?

Well, not so much... started up, runs great, no codes, but only 4psi indicated. . ugh. #@$%!



Any ideas about what I should look at next?



Thanks

 

[JR]

if you are running an electric fuel pressure gauge i would first verify with a manual gauge to make sure your seeing correct readings. Even mechanical gauges can fail, but not nearly as often as electronic. Also check to make sure your adjustment screw hasnt worked loose over time causing a decrease in pressure. im not positive but I think there is a spring behind the adjustment screw, maybe there is something stuck in there or perhaps the spring has worn out? just a few ideas before condemning the pump.

 

[SMcGrady]

if you are running an electric fuel pressure gauge i would first verify with a manual gauge to make sure your seeing correct readings. Even mechanical gauges can fail, but not nearly as often as electronic. Also check to make sure your adjustment screw hasnt worked loose over time causing a decrease in pressure. im not positive but I think there is a spring behind the adjustment screw, maybe there is something stuck in there or perhaps the spring has worn out? just a few ideas before condemning the pump.

My gauge is mechanical. Good idea to hook up another guage to verify the discrepancy. I have a snubber installed between the fuel line and the guage. I am not sure if anyone has had experiance with them failing? If I can find another guage to test with, I will check it pre and post snubber too.

I am not sure where the adjustment screw is, but I will take apart the guage pod and look around in there if it points to a guage problem.

Thanks.

 

[JR]

My gauge is mechanical. Good idea to hook up another guage to verify the discrepancy. I have a snubber installed between the fuel line and the guage. I am not sure if anyone has had experiance with them failing? If I can find another guage to test with, I will check it pre and post snubber too.
I am not sure where the adjustment screw is, but I will take apart the guage pod and look around in there if it points to a guage problem.
Thanks.

There is no adjustment on the gauge itself. If you have the same pump that I think you do, you should have an adjustment screw on it to increase/decrease pressure. Check to make sure that hasnt come loose. Sorry about the confusion

If you have this style the screw with the jamb nut is the adjustment. If you have the pump with the twin filters I believe the only way to make pressure adjustments is by changing springs. There may be something plugging the inlet or spring that is affecting your pressure.

 

[klcammie]

I heard once that the ball at the end of the spring was plastic and can squeeze up into the spring. The guy used a thin washer between the spring and ball to fix it until he could replace the ball.

 

[SMcGrady]

Thanks for the help. Sorry I haven't replied sooner. My Dad passed away suddenly and I had to drop everything and go. Things are still kind of in a state of confusion with the family so I am going to have to hold off on figuring out the truck's problems for a bit. I'll check in when I get a chance to work on it again.

 

[JR]

So Sorry for your loss.