You should check the EGR operation - instructions are in the FSM. There's a vacuum switch on the front of the thermostat water box that has 2 nipples that are prone to cracking. I'd chack that switch carefully. Often, they're cracked and leaking, but not completely broken off.

Frank

'89 [color:"white"]G-Raider[color:"white"] [color:"black"]Supercharged 3.0L, MegaSquirt 2, lockup A/T, 2.5" exhaust, 172k, Cibie H4s/Oscar SCs, Hella Micro DE fogs, Cobra CB, Superwinch hubs, LSD rear/Aussie Locker front, Bilsteins, Lifeline AGM, Rust-Oleum