Indexing distributor

I have searched and searched and tried and tried and I can't quite get this right. Can someone walk me thru installing a distributor in a 91 XJ 4.0? I keep going thru the motions and with a timing light it still comes up about two teeth off. It has a very long crank time before it starts and if you give it gas while it's cold it backfires thru the intake. Once it warms up it runs fine. The computer has just been swaped with a junkyard transplant with the exact same numbers as the stock ECU. Any help would be greatly appreciated. Thanks in advance.

You need to bring the no.1 cylinder to TDC. Find the timing mark on the harmonic balancer pulley and make sure it lines up with the 0 on your timing pointer. Then line up your rotor button with the no.1 spark plug tower on your distribuitor. There may be a no.1 mark one your Dis. housing I can't remember. Anyway after all is lined up then install. Remember the rotor is going to turn clockwise when the dis. slides in, so you may have to turn the rotor back off your no.1 mark a little so it will line up when the dis. slides in. You should be able to adjust your timing from there with the light. Good luck.

If it's running at all you most likely will get no good information from a timing light, because the ECU will correct the timing on the fly even if the indexing is bad.

I would mark the position it's in now, and try moving it one tooth in either direction. If it runs better one ahead, leave it. If it does not, try one behind the original. If it doesn't run better then, I doubt indexing is your problem.