Dfi running rich at idle/light throttle

My 86 voyager tries to load up and foul plugs when it's idling and when you're cruising at light throttle. Otherwise runs great, plugs are golden brown when it's been run hard. Black with soot when it's been idling.

Any ideas? My throttle sensor tests fine, as does the temp sensor. No ECU codes. Just looking for what to test next

Thanks!

Probably less depth of knowlege on injection than carbs here! I know Very little but owned a lot of Ford Capri 2.8i in the 80's and dirty injectors caused all sorts of low speed running problems as the injectors would spit rather than spray but higher revs would run ok with the higher pressure..not an answer but an idea, clean injectors probably as important as clean carbs.

There is a one way valve that's screwed into the underside of the fuel tank; if that's seized it can cause high system pressure & hence rich running. Empty the fuel tank, remove it & try to pass a screwdriver up through the valve, you should be able to do so with a slight bit of resistance, if not it's seized.

the valve under the tank is a relief valve from the fuel rail.. and they clog all the time.. I have had them stick on 3 different zn 1300 that I own. I would at least start there.. this is a known problem for fuel injected 1300's ..

Dirty injectors crossed my mind, I've been running seafoam through it but it probably could use a professional cleaning. I just got the bike, it has been sitting for years

I'll pull the return relief valve and see if it's clogged, thanks for the help! I'm hoping it's something simple like this

the injectors are not dirty, if they were the bike would be dropping cylinders [missing] the fact that its loading up means they are putting out fuel. if the fuel relief valve is sticking then then they are putting out to much. all the relief valves on my bikes were stuck closed because the bike sat to long. soak it over night in carb cleaner.