Alfa Romeo Repair: Intermittent Loss of Electrical Power to Engine, throttle position sensor, lambda sensor

Question
I have a 1996 2.0 Spider.

I have been having intermittent losses of power to the engine for a second or so, and sometimes I get a dull acceleration with the engine eventually dying. I brought it to the garage at it's worst and they replaced the Lambda sensor which fixed the dull acceleration for a while, but I am still getting the intermittent loss of power.

When this happens the spark plug warning light flashes on/off, and where I lose power for a while turning the key back a notch or two and then on again usually returns the power OK.

The garage swapped out the plugs to eliminate these, but they seem stumped (Alfa Main dealer).

Any ideas ?

Ian

Ps. I also get some erratic idling - I don't know if this is connectedor not (probably not)

Answer
Several things need to be addressed just as tune improvement.
Switch to an aftermarket coil such as MSD or Accel.  Switch to NGK spark plugs.

Now for the specific problem,  Check the throttle position sensor and its connector.  Also, check the volumne and pressure of the fuel pump.