4.3 gi volvo issues

Hi folks, season up here coming to a close, maybe someone can assist with my issue, twin 4.3 Fuel injected cobra (volvo\)port engine does not want to idle down to spec 600 rpm, it seems to want to sit around 1500 rpm, anybody have this issue, it is computer controlled,
new thermostats installed, engine does get up to temp but doesn.t seem to stay very hot, runs good, oil pressure on idle drops to 20 psi, but rev it up it performs as good as other engine.it does tend to smoke till it warms up a bit,nothing to major, starboard engine idles at 40 psi, no issues
I have not compression tested yet, but am wondering if it is MAP sensor, smoke is possibly fuel related, unfortunately nobody seems to have a code reader...
any help would be appreciated

Re: 4.3 gi volvo issues

isn't smoking at start up usually valve guides? and as for the computer control i have no clue sorry but good luck!