Starting Issues…Fuel system?

[Nilao]

My Guage tends to fluctuate as well. My sending unit is in my rrivers tank. It's the crown of the road. Some of the driver tank fuel goes to the passenger tank from gravity. The passe ger tank is lower than the drivers on most highways when cruising in the right lane. Once parked and idling the tanks equalize once on level ground causing the level reasing to be correct again.

The hard/slow start could be the gear fuel pump. It has to be able to get the psi up to a specific amount before it will fire. You need to get insite and watch the measured fuel psi during cranking. The rpm fluctuation cold could be this same problem or it could be the actuators are worn out allowing unmetered fuel to be injected.

The cranking issue I am presuming to be the starter engages then just quits cranking if I'm understanding what your trying to say...that could be the ignition switch, relay, solenoid or starter TBH.

Fuel.mileage is going to be dependent on several factors. You being number one, and second equipment condition/specs. Take mine for example. I know I most likely have a bad injector and a leaking actuator as I have a noticeable miss at cold start and around 1300 rpm I have a vibration like a misfiring injector. I need to put it down and fix it but it's not in the cards right now. But if I was to fix those issues I could probably pick up a bit of fuel mileage.