Actually the engine will start everytime with the lack of a cam signal. The cam signal just allows the engine to know where TDC of Cylinder #1 at injection time before the complete first revolution of the engine (for injection). This will just aid in starting the vehicle quicker. Without the cam signal the engine must be timed soley off of the crank sensor which means that the engine must have 2 complete revolutions to figure out where it is. While running, the engine does not require the cam signal. I have personally worked on a bonneville that lost the cam signal (which is conditioned in the ignition module). The problem with that car is actually in the ignition module but not a big deal as it still starts fine.
Do you have the old cam sensor. Is it actually damaged? The cam signal is not going to cause an engine to run rough. It could be a problem with the ignition module itself. The module conditions the crank signal and the cam signal from an AC sine wave into a DC signal. Check the ignition module. I think that you may have to do a little more looking into this. Has your mechanic offered to take the car off your hands for a good price? Really, look into this further - pull out the new cam sensor and see if it is indeed damaged.
1992 Bonneville SSEi
White, grey Leather interior.
Tinted windows and blackouts on headlights.
Custom high flow exhaust, Everything replaceable - DONE
300 000 kms original engine, tranny 2 rebuilds.
Playboy Bunnies Embossed in Tint. Oh Yah!
Ever Seen a Polar Bear in a Snow Storm?