90 Testa starting problem & trans oil

Hi guys, I'm getting an intermittent problem which I suspect could be the warm-up regulator or fuel accumulator fault.

Car always starts first crank cold but now when warm if I shut it, it'll need many cranks to start it up. I need to leave it for a few mins before it'll fire first crank again. There's the usual swirl sound from the starter, fuel pump has sound but fuel doesn't seem to be coming in or igniting while fumes would be blown through the exhaust once a while. Could it be coil, relay whatever?

How do I trace it & has anyone installed a fuel regulator with a gauge in their TR's fuel line? Where do where install it? Before or after the fuel filter & what PSI gauge should I be getting?

It's been raining a lot here & car's went thorough several heavy downfalls but problem comes in even when weather is dry.

It's not reached the point where it'll not start everytime I park but it's acting up & I woudn't want to get stuck one day.

Lastly, what oil do you guys use in your gearbox? Will redline make it smoother? (Claimed by many 348 owners)