MustangSteve wrote:

I am probably more guilty of adding things that cause extra work and grief than anyone.  427 with TKO in a 66 is a good example.  I just never have understood the need for an electric fuel pump on a street driven car with a carburetor.  The manual pump will work nearly forever and cost 1/3 of what that tow job cost you, much less what you paid for the pump and the wiring and the gauge to monitor why it is not working.  It is an item that I see as NO IMPROVEMENT over a factory piece, so that is why I am always dismayed at why anyone would do that to themselves.

Oh, and that "I will keep quiet" thing...  Yeah, right!!!

But, to answer your original question... Is it possible you have a piece of teflon tape used on the threads?  It could be blocking the sensing port of the gauge, which is a very small hole. Or fuel tank crud could be blocking the hole.

 
Steve, you having a bad day man ?  The attitude is somewhat questionable. It's been 8 or more years since my last visit it this forum and thought I would pop back in with a question on a problem I'm having, but that can be rectified. I'd like to thank the people that post some ideas on the problem and I'm sure I will come up with the answer to it, I always have.

 

The gauge is reading steady when it is reading, the needle doesn't bounce around or fluctuate when it's working. Randomly upon start up of engine the gauge either does not read any pressure, or it reads 3 psi or 8 psi.   
 
 

 
 
I really don't know for sure if the gauge is hooked up to an actual 12 volt wire. I have a couple of wires under the dash that I found and have other things hooked up to it also. I know that the positive wire that the gauge is hooked up to only has power when the ignition switch is in the on and start positions. The instructions to the gauge does say that I need to hook the positive wire up to the ignition switch + 12 volt connection and to have an inline 1amp 3ag fuse, and I do. It also says to have the ground wire to a good engine ground with a picture of the ground wire running to the negative side on the battery.I have the ground wire grounded to the metal dash just like all the other grounds for oil ,water temp, volt gauge lights.  I'm going to go out on a limb and say I don't think that would make that much difference, or would it ?  I guess I could take a volt meter and check what kind of voltage is at that + connection I have the gauge hooked up at.  
 
 

I have an Auto Meter UltaLite model 4361  2 1/16 inch electric fuel pressure gauge that I can't figure out. I have a new airtex in line electric fuel pump that should put out 5 to 9 psi.The pressure gauge reads all over the place.Some times it will not read at all,  sometimes it reads 3 to 4 psi and some times it reads 7 to 8 psi. This is a used gauge and sending unit with a new wire harness. I have a good ground and good connection on the power supply to the unit. What is the problem, could I have a bad gauge or sending unit ?