Chrysler Repair: Trouble starting and error code 51 on my 98 dodge neon, lean mixture, dodge neon

Question
hello roland im back lol well how you been i had a little trouble with the neon again well in the mornings or when the car sits for a while it take me to turn the key on and off like 6 times so the fuel pump will pump enough so it can start and when it starts it runs good but maybe a little rough idle and i also had a code come up it was 51 that mean lean mixture and i checked to get a fuel regulator and u cant get one for the neon and the pump cost 200 bucks i also checked how much presssure was on the fuel line and there was nothing come out so could you help me roland and thank you so much for helping me  

Answer
It may well be that the pressure regulator is not maintaining the pressure at the required 48-49 psi. You would want to mearure that with a gauge, but if it isn't pressurized immediately after trying to start the car then that would be indicative that the pressure isn't there. But whether it is a clogged filter on the fuel pump inlet, a clogged filter on the outlet of the pump, or a defective regulator would be determined by inserting the gauge via an adapter at the points between the various parts of the fuel line from the tank to the return line. I am sure that a pressure regulator is available at the dealer if not an aftermarket parts store if that is the cause.
If the pressure is o.k. then the 51 code could be due to an exhaust manifold leak. Even having a very low level of fuel in the tank can exacerbate the problem. Injectors stuck closed can cause too lean a mixture, even poor spark due to a weak coil, worn plugs, or wires can cause it.
So I think you will need to get some fuel pressure measurement to see whether or not you are getting 48-49 psi and if you do, then go on from there to check the other possibilities.
Roland