99 C1500 Suburban with 5.7.

Over the past few months it has been bogging down occasionally when accelerating immediately after a warm re-start (perhaps 5-10 times over 4 months). Our ambient temps here are rarely above the mid 20's C (~75F), so the issue seems only to be engine temp related. Only notice the bogging when accelerating on entry to a road where throttle is called for. The bogging only lasts for 5-10 seconds or so then power comes on - it is not accompanied by stumbling, missing or other symptoms - just no power. Once it clears, the engine runs fine and if I shut down and restart immediately to try to recreate the issue, I've not had it repeat - so it seems to be related to a period where the engine can heat soak for a few minutes but not cool down (like stopping for fuel or a short stop at a store).

The truck always starts immediately on cranking. There are no codes, no misfires and fuel trims, O2 sensors, MAF etc look good on the scanner (I use a Foxwell). I've hooked up a fuel pressure gauge and taken it for a drive and all seems to be OK. I read 52-53 psi at idle & 58-60 when revs are >1000 with no fluctuations. Pressure holds w/in 10 psi for over an hour on shutdown. NB that the engine was converted to MPFI several years ago and these readings match tests done then & as I understand are in spec for the MPFI system.

I've replaced the fuel filter, rotor/cap and plugs - no change. Plugs and wires are fairly recent and look OK.

Suggestions on where to look next are welcome - could it be running too rich on restart, be a fuel volume issue or ??