Hey there. Just swapped out my old engine with one with over half the mileage of the old one. 265K+ miles VS 110K.
Got everything plumbed up, no oil leaks, no coolant leaks. I'm almost 100% sure all my vacuum lines are where they need to go, and all my wires hooked up. It's not throwing any codes. Starts right up, sounds smooth, idles fine revs great... that is when it's cold.
Once it starts getting up to operating tempature, it will still idle, but if I so much as touch the gas wrong, it just dies. If I kinda blip it then push on it slowly the revs will raise all the way up, but if I press to hard it just won't do anything and sounds like it's bogging down. And if I have the revs held up high, and let off the gas and let it drop normally, it also dies.
Someone mentioned something about the torque converter stalling if it was low on fluid. But it's completely full.
I used all the old sensors, the throttle body, injectors, wiring, everything from the old engine. Well all besides the little thermovalve underneath and to the right of the throttle body. And the IABs.
If anyone could shed some light, that would be greatly appreciated.
Start with replacing/cleaning your Iacv and check your engine coolant sensor.
Replace your PCV valve while your at it.
If all else fails I would look for trained acura/honda mechanics that have had experience with legends, they love these cars.
I personally would let my car warm up. Once warm fully open my idle adjustment screw. And see if it stops stalling. If the stall continues shut off the car and loosen your throttle cable. Ask a buddy to start the car for you and begin adding tension on the cable until it idles enough to not stall if the cars about to stall rev her up by opening the butterfly by hand. Once idle is set by cable tighten her back up and begin adjusting idle until youve gone as low as possible but never below factory recommended idle.
Being a couple hundred rpms over factory idle is ok, it won't hurt anything. I turned up my own idle just because it idled smoother. 360k miles