the blue plug is for the mixture solenoid and the white one is a throttle position sensor.you're not gonna get those to work without a computer.that is a computer controlled carb. might work without the electronics hooked up.make sure you stretch the spring for the power enrichment.clean the rods.check for worn throttle shafts also.Very common on an older unit.check the bottom of the float bowl.there is a plug down there.make sure it's still sealed.or it will always run rich/hard start as it will slowly drip gas into the intake.

Well, I believe I've found my whistle. I had carb base gaskets that did not seal.
the original 4bbl intake we are using had the old little square Carter. The 3 sources we checked could not locate a kit for the old Carter. Our remaining choices were a well used Carter AVS, a Thermoquad, and the Quadrajet. The Quadrajet won out because it was the best looking (cleanest, most complete, and most unmolested) one to start with and the electric choke was a huge + because there was no choke provision on the intake. Being too cheap to buy Hotheads $50 adapter, I spent several hours making one (real cost effective) then I had to add the spread bore adapter on top of that (if you counting, that makes 3 carb base gaskets) The base gasket between the spread bore adapter and my home made adapter was the one that did not seal. I'm sure homemade gaskets didn't help much either.

So today I filed my homemade adapter more flat (again), made new gaskets, used weatherstripping glue on top of the home made adapter, and bolted the whole mess together again. It lasted until the motor warmed up and then the whistle started coming back.

Time to regroup and rethink the process. The fix is only $400 away. Gene

Were you trying to find a kit for a Carter WCFB? I am willing to bet they can be found.