Would a timing chain cause my van to stall out then turn ignition all the way off and starts up again and runs fine for three to five blocks then stalls out again
No, check relays especially, ASD relay since it controls fuel and starter. However, do some test first before going there...You do need some tools at your side when this occurs. A spark tester,
which you can get at a Auto parts store, and starter fluid. When this
happens again, test for spark by taking and plugging the tester into the
spark plug wire...you sometimes can get it high enough that you can see
while you reach you hand inside to turn the engine over. If you have spark. If you aren't getting any spark, go to the coil and module and cam sensor which is close to the front of the alternator...If you have spark then disconnect the air intake so that you can have access to the throttle body and spray some starter fluid into the the throttle area to see if the vehicle will start. If it does, this doesn't mean the fuel pump is out although that could be the case, but it does mean that the vehicle isn't getting fuel for one reason or another. At this time you need to check the ASD relay and starter relays, sometimes the ASD and starter relays are combined.You can check them by having someone switch the ignition on, don't turn it all the way over to start, and while you holding the relay; you should feel a click. However, this needs to be done while the vehicle is running correctly, so you can compare what is going on opposed to when it stops. The relays are on the battery side of the vehicle, and the ASD relay is the one closes to the washer fluid tank. There are usually five. The 1st two are important to this matter. You can tap anyone of these with a screw driver at the time of the stall and it will cause them to work again if that is the problem. You also, want to listen for the fuel pump to be working during the time the vehicle quits. This allows you to know whether the fuel pump is getting power to it, which again gets its power from the ASD. The other culprit in this matter is the PCM, which is located behind the battery on the fender weld. They can be hard to test when they are doing this; however, you should be able to get one at the junk yard for a low cost to eliminate that possibility. This is the last thing that you want to do if all else fells...good luck.
This was all I had and/or could find. Hope this helps you....
