Hey everyone, I'm back for your expertise!

2000, 2 dr

So I'm having a rough idle in gear sometimes at lights, stop signs etc. And during the rough idle, I can watch my voltage fluctuate around and my lights dim in time with it. This doesn't always happen, not sure if I'm imagining it, but seems to be more when there's high moisture outside. I also have to try twice to start my truck a lot of times. This seems to happen more when it's hotter outside. I've had days of running around town and having to try twice to start every single time, and other days where it started perfect every time.

I replaced my fuel pump last year, fuel filter this year and so I'd like to rule that out first if I can...I'm a pro a dropping the tank now (after going through 3 bad pumps...never buy off-market again...and trying to figure out why my gas is overfilling out of where the pump sits) but that doesn't mean I like doing it!
I can hear the pump prime when I turn the key, even if it doesn't start that first time. Would the gas leaking mentioned above have anything to do with this, is the tank supposed to be a pressurized closed system? If so, I have a new gasket, just want to make sure I don't need a new whole pump before just going in to replace the ring.

I know you can test the fuel pressure, but where about is the port for that and is there any special gauge or adapter I need for this?

Any other ignition switch symptoms? There's lots of little quirky things wrong with my truck I may not even consider related.

Any help is much appreciated! Thanks guys!

 

The schrader valve for testing the fuel pressure is in the engine bay on the fuel line at the back of the engine. You'd need a fuel pressure tester to measure it. It need's to be at 55+ when it primes, then remain above 50 for 10 min. If it drops, you may have a bad fuel pressure regulator (fpr) or a leaking 'nut kit.'

 

For that year it needs to be 60-66 psi and then remain at or above 55 psi for 10 minutes after the pump shuts off.

Fuel test port is on the drivers side behind the throttle body.
Do you have any check engine codes?