My 740 turbo recently started running like shit. A while ago, the impulse sensor in the distributor was broken. I took the dist off, put on a new housing with the sensor, and bent some metal parts inside back into place that had probably physically hit the sensor and broke it.

Afterwards, the car would run and drive, but misfired often under heavy load (ie getting up a hill was next to impossible). Well now, when I start it, it will run for half a second, the idle drops below 300rpms, and it dies. If I keep the gas up it'll run and drive, again with many misfires, but if I let the gas drop it dies. Once the car is warmed up it will stay running, but the idle jumps between 300rpm and 800rpm.

I did set the timing after replacing the impulse sensor. I also thought the poor performance might be the result of the inside of the distributor cap being dirty and the plugs being old, so I replaced both the cap and the plugs today, with no noticeable difference in performance. The only other thing I've noticed is the plug wire for the #1 plug doesn't 'click' in like the others do.

I'm not really sure where to go next, but this is my only semi-working car right now and I need it fixed. Help!
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1985 740 Turbo // 1999 VW Jetta TDI