I’m at a dead end with my ‘94 NAS. Truck seems to run fine but once driven for 30 minutes or so it will no longer idle. It will start right back up but then dies in seconds. I’ve replaced iacv, distributor, ignition coil(s), chicklet, plugs, wires, O2 sensors, fuel pump, fuel filter and I’m sure a couple others things I can’t think of at the moment. It’s been to two shops, one of which is pretty familiar with Defenders. Any suggestions on what road to go down next?