My '83 240 has a weird engine stumble.
After I start the car, the first time I accelerate, the engine cuts out. It happens only once per start and it happens every time, with the exception of a few out of hundreds of starts.

It has been this way for months. I have just gotten in to the habit of starting my trips by revving in neutral to induce the cut out. After that she runs like a champ and accelerates smoothly. If I forget, it normally happens a few minutes into my drive, not nice if its when I'm pulling into traffic!

I've gone thru all the tune up stuff: Cap, rotor, plugs, wires, fuel filter, clean air filter, replaced cracked vac hoses, o2 sensor, checked fuses.

The only thing that seams to be loosely connected is that the problem arose soon after I installed a rebuilt cylinder head (old one cracked.) I wonder if I could have damaged a wire or sensor in the process? But nothing is obvious and I don't know where to start. I don't see the good in throwing parts at it.

Any tips or testimonies of similar issues would be very helpful.

Thanks!