First, check all of your vacuum lines and electrical connections. Pay particular attention to the big connector on the distributor for the trigger points for the injection. Pull the rubber boot back on the connector and look for broken wires. Also, look very carefully at the injection system ground wires bolted to the engine block. See if any are broken or pulling apart by the bolt.
Second, go through the ignition system. Check/ replace spark plugs, check ign. point gap and timing. Check the dist. cap for cracks. Look at the engine at night while it's running, and see if you see any sparks jumping from ignition cables to ground. Correct as necessary.
Hint: You CANNOT diagnose a D-Jet system UNTIL the ignition system is functioning 100%, or you'll drive yourself totally batty.
Do all of this first and then we can go from there.

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