Fuel pressure at idle means nothing, unless it is high enough to blow the needles off the seats.
Actually, fuel pressure for a streeter means pretty much nothing , period, unless it blows by the needles.
The only time fuel pressure means anything, is at the big end of the track, and even then; it only has to be enough to keep up with what the engine is consuming.
The thing that means anything at all, is volume. So if the pump, can't keep up at idle, then the very first test I'd be doing is a volume test.
But in this case, the car has already been running and driving for a third of an hour, so until this moment or shortly before, both the pressure and the volume were fine. As to a loss of fuel delivery then, IMO, the only considerations are; tank venting, and maybe, pump efficiency.
What I have found is that when the tank comes under vacuum the pump stalls because the diaphragm fails to return, and so the pump-arm just flops around uselessly.
But OP has already stated that the tank vent is "fine".
So by process of elimination, we have sorta come to electrical....
unless the valves are failing to close.
BTW, OP
the ignition system will run just fine without the coil ballast. In a pinch, I have run the ECU of either side of the dual-ballast and just jumpered power to the coil. My Big Yellow Sq-top Accell Super Coil has spent a few hours running full voltage and survived just fine. In fact, it has spent a good bit of time jumpered straight to the battery, bypassing the entire electrical system. I carry a jumper in my kit, just for such an occasion. You won't see my car on the side of the road on a Sunday, with me walking, unless there is also a huge puddle of liquid under it.
I don't carry a cellphone and never will. To me, a cellphone is such a flippin' distraction,and a crutch for all kinds of bad manners. If I am with a person who interrupts our conversation, to answers his/her phone,
chances are I'm on the way of capital G, G-o-n-e.
And that goes for the parts guy at the parts counter too. I'm here with cash in hand to buy something. If he answers his phone while serving me, guess what: I'm gone; He ain't the only game in town.
But I digress..... lol
