Dodge Intrepid Switched Engine Promblems

Ok we have two dodge intrepids one from 2002 and one 1999. The one from 2002 has frame damage and we took the motor from the 2002 and switched it over to the 1999. The 1999 motor was cracked and we still haven't done anything with it. But now the 1999 with the 2001 motor in it doesn't want to start. It's about to start and it sounds like it's going to start, but the spark doesn't want to go off to start the ignition process. We took it to a dealership to do a computer check on it, and they said something about the crank or cam sensor not working. I'm not sure if it needs a different sensor, or something else. These are my brothers cars, and I'm trying to help him out, so if something that I wrote isn't clear, I can ask him and clarify. But I remember hearing something from my other brother who said that someone he know's had to drill a hole somewhere in the back of the motor, and put the cam or crank sensor in their. Any help whatsoever would be extremely appreciated because it's been a year since we've had this promblem, and we've had mechanics look at it and they couldn't figure out what the promblem is. Thanks!

Engines are usually grouped together in years of interchangeability. Such as '99-'01 and '02-'04 (only an example, I don't know the grouping for the Intrepid). Most junkyards can tell you how the engines are grouped for compatibility. They are grouped this way for both compatability and emission puposes. If you have a '99 car and you put an engine in it from a newer year that is not in the group, you are required by Federal law to upgrade the emissions on the car to the level certified for the engine. That is why most times a manufacturer will make sensor or other changes in an engine, to prevent people from putting in newer engines into older cars and violating emission laws.
You may be able to talk to a local Junkyard and they may know what the differences are, this would help you solve your problem. It may be a matter of moving the sensors from the old engine to the new one. I would have put only the motor (with heads) into the car and took and intakes manifold and injection off of the old engine and put it on the new one. I've had this problem before in one of my swaps and after switching the above mentioned items, the engine start right up.

There were quite a few changes in between those years. None too serious except the '99 and the '02 use different tone rings for the cam position sensor. I'm working with that problem now... It's mounted to the sprocket on the drivers side exhaust cam. I think you only have to take of the valve cover to access the sensor wheel..

are both engines 2.7litre, if so i ran into this problem with the gm dealership i work at, i am a tech and a intrepid came in with motor knock and found bearings are all badly damaged from lack of oil getting to the bottom of engine, all the oil stays in the top causing bottom end to get hotter and sludging the oil, also the oil passage ways are tto small, but back to you no start condition, the cam reluctor is different and the flywheel where crank sensor reads is also different.

I've seen in some other discussions that in some of the other engines, you can't make the newer engine work b/c they changed the crank sensor pickup position and the magnets (or whatever they use) are of different arrangement on the crank. Some have swapped cranks and drilled new holes in the block to move the sensor, but that seems like too much work to me.