1988 4.3 G 10 Van

[leifcoburn]

I and my mechanic(s) have replaced and checked everything I know of on this van but it still idles with a hesitation

 

replaced- elect. spark control, map sensor, knock sensor, o2 sensor (twice), computer, manifold pressure sensor, distributer, dist cap, rotor, wires plugs, egr, rebuilt carb, new injectors, coil, air idle control, catalytic converter, throttle sensor

 

checked manifold pressure and cylinder pressures fuel pressure - okay

 

The only other thing I can think of is that there is an orange wire going to the transmission solenoid that is disconnected. I cannot connect it or the transmission slips. it as been disconnected for years.

 

I have been driving this van for close to 20 years and have had almost no trouble out of it beyond regular maintenance and a new engine 25000 miles ago. Really want to fix this as it is in great shape and looks great for it's age.

 

any ideas what it could be?