VQ25 runs but stops under idle

[RVS1]

Hi Guys,hope this is the correct place,i have a cefiro 1995 VQ25 engine,the thing starts but wont run well,if you feather the throttle up you can run around 2-3000rpm and it sounds fine,below that it misses a bit,no fault codes are set,know my way are the SR20DE engines no probs,also i noticed that the mufflers got extremly hot in a short period of time,i mean when i touched the rear muffler i burnt my fingers,although the amount of exhaust gases dont point to high backpressure,when you crank it up it will start for a few seconds then die,as above throttle on and you can keep it running,have removed sparkplugs and coils,plugs do seem a little on the black side,any info on how to test these coils,any help would be great,cheers RVS1 NZ

[Nahkapohjola]

Coilpacks die by the mile, suspect after 100kmiles.

IACV needs cleaning 'every 60kmiles'.

Rubber hoses get brittle, resulting air leaks affects first idle.

Oxidized connectors, see link p.14 below, may cause 'anythin'