I posted my concern regarding my FP gauge on the CF a week or two ago... thinking maybe my lift pump was the issue. KATOOM indicated that gauge may not be working correctly and suggested I contact ISSPRO. I posted in their sponsor's forum but no response.

I just read another post regarding the FP gauge when the truck is turned off... whether it should or shouldn't drop to zero.. and the consensus is yes it should. 

I just checked mine and it does not drop when I shut down.

Here's a video of a first start this morning. Shows the pressure at 16 from last night.. what happens when I turn the key (which was my intitial concern a couple weeks ago.. no build in pressure).. then I bump the starter to let the pump do its 25 second cycle.. then a turn on and start. 

I initially thought it was my lift pump because I don't hear it when I turn the key (I thought I used to) but it always fires up instantly... 

Do I need a new gauge? Sensor? How do i diagnose this?

 

Edited February 25, 20169 yr by dodgedieselnewbie

Normal. I'm also running a ISSPro EV2 gauge and it will NOT drop to ZERO when the key is turned off. It will display the last reading. That is because the power is cut to the gauge and stepper motor does not have a return to zero spring. So it will just display the last reading till key on. 

Looks to me like the gauge remains at whatever the last reported psi was after shutdown.  the rest of the operation looks normal.

 

Contact Issopro and see what they say.  

Sounds like you need to verify it with another gauge.  This is the reason that I would like put a test port in to connect to a test gauge.  That would take the wonder out of it.

Thank you... how about the no pressure when key is turned on before starting.. normal as well?

An electric gauge won't show pressure during starting.   You'd need a mechanical gauge for that.

3 minutes ago, Hawkez said:

Sounds like you need to verify it with another gauge.  This is the reason that I would like put a test port in to connect to a test gauge.  That would take the wonder out of it.

Already got a test port just add a tee and test gauge... 

Edited February 25, 20169 yr by Mopar1973Man

Awesome.. thanks!

some trucks only power the lift pump for a split second also when you key on, so you won't see any pressure until cranking.

Just now, Me78569 said:

some trucks only power the lift pump for a split second also when you key on, so you won't see any pressure until cranking.

The key on bump is meaningless and just a software thing. Has no impact on lift pump pressure or performance. Just when the key is turned on the ECM boots the software and the lift pump may or may not run. Again depends on the software that is loaded on the ECM. 

Okay... and I can assume my FASS is working correctly (becasue it starts easily) even though I don't hear it when I turn the key on... like I thought I used to? I definitely hear it during the 25 second cycle.... 

Edited February 25, 20169 yr by dodgedieselnewbie

8 minutes ago, Mopar1973Man said:

Already got a test port just add a tee and test gauge... 

Sorry Michael, I was suggesting that the OP have one.

19 minutes ago, Hawkez said:

Sorry Michael, I was suggesting that the OP have one.

Just showing off how to have a nice test port for the OP. Way better than fighting with a sensor on the VP44 line. I'm working on getting these brackets produced for sale. Making gauge install easier and testing easier. 

Edited February 25, 20169 yr by Mopar1973Man

I really like the set up that you have and I would like to do something similar.  One day...

Seems perfectly normal for electric gauges. If you're really concerned about it, tee in a mechanical gauge to double check.

This is why posting video's can be more helpful.....  Because that video shows a perfectly normal gauge operation.  You're good.....