thanks, mrray <img src="/forums/images/graemlins/cheers.gif" alt="" />
.
today I put my mightyvac to work,,,cheched EGR and Evap solenoids/system for leaks. Then checked brake booster hose and booster out. No problems found.
Then swapped in my spare ECM (takes a little doing on mine because I relocated it above the water line,,above and behind glovebox).
No change , idle pretty steady at 1,400 rpm as before.
Stumped <img src="/forums/images/graemlins/confused.gif" alt="" />
I stuffed some cardboard on the front of radiator to try to overheat a bit on the H20 sensor, but I don't have AC stuff blocking and it's a fairly new Modine 2 roll --it didn't get very hot.
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Tomorrow I'm gonna start back at square one and buy a new 195o thermostat.

dave h.
'89 Raider V6 5spd;Aisin Hubs;; Gen2 LS: frt. brakes, rear coils;U.C.arms;R.trailing arms;idler arm; rear LSD axle w.disc brakes ;2 battery system for Dog's fan; relocated ECU; custom bumpers;J.Baker receiver;Conferr roofrack; t-bar crank.