I've got an '85 735i (180k) Starts up fine. Idles fine. Revvs up smooth and then when it warms (3-5 min.) Up it begins running rough. Seems to be loading up. If I cut it off at this point it won't restart. After letting it cool down a few minutes it still won't start up due to fouled plugs. When I change the plugs and it starts fine begins same thing over again. I've checked fuel pressure it is steady at 40 psi with no bleed down. All tune up items are good (computer, distributor cap, rotor button, etc.) Temp sensor I think is good. Air flow meter is good. Pressure regulator good.
What should I try next?