Thanks for the response.

the stall is under cold conditions, not hot. no stumble like its running out of gas when it happens. just like someone flipped a switch, even when it started right back up.

I have been trying to look at this logically, and it seems to me if the filter was clogged it would be more like fuel starvation symptoms. if it were the relays it would be a hot relay cutout type scenario, right?

what would be the symptoms of a bad fuel pressure regulator? should I focus on that at this point?

thanks again for any responses.

BTW both pumps energize with the hot to 5 on the fusebox.

Two FI relays above passenger feet. Two small metal cubes.

Vacuum leaks and grounds are important to a good idle. I just realized after some time that the quick release ground connection on my cable was not grounding as good as it should of been. I connected the cable straight to the battery and now my idle is nearly always good.

I recently had a vacuum leak fixed thanks to another thread on here about the clamp around the intake hose to throttle body not keeping a tight fit. I used a cut piece from some paper gasket material found at national auto parts stores. That helped. Make sure all the nipples on the intake manifold are being used or plugged. There are a couple grounds on the manifold too, black wires under the bolts that hold the injector rail on I believe.

Not sure about the stall when hot.