No Attempt to Start At All ***H E L P***

97 MKIII B2500 Conversion w/3.9 and 201K mi.
Van has been good, no issues till blown water pump last week. Actually saw water coming from around shaft and fan pully area... so I replaced it (quite a P I T A ) but I am pretty sure I got it right... Had to do it from the bottom, but only took three hrs. Now... here is the wierd part. This van has always started, never had any issues with that until now. After I refilled coolant and reconnected the battery I attempted to start it. It turned over once, I heard a loud "pop" sort of noise, no smoke or vibration though. By myself so I did not SEE anything under the hood... now, when I turn the key, the engine turns and turns and turns and turns but does not even attempt to start. As if no spark at all. Wha happened ???
Any clues would be greatly appreciated.

As if no spark at all.

Is there spark?

I appreciate the reply. I enlisted the aid of my son to help me diagnose the issue. Now I have diffeent questions.
To answer your question.... no, no spark from distributor but the coil was good as tested in another vehicle. HOWEVER, further investigation revealed that the rotor in the distributor does not turn at all. Removing the distributor revealed that the distribtor shaft is intact but the cam shaft is not turning either. My guess is that the "POP" I heard was the timing chain breaking. My question, Is this job something a backyard mechanic like my self can tackle? Does replacing the timing chain/gears require any "special" tools?
Any insight would be greatly appreciated.
Thanks

The entire front of the engine has to come apart in order to replace the timing chain. It is a job that you can do at home with the most notable "specialty" tools being a puller to remove the harmonic balancer and a torque wrench for reassembly. Since you will have to do several realignings such as the crankshaft timing gear, the camshaft timing gear, TDC, and the distributor, I highly recommend you pick up a repair manual so that you have the correct procedures on hand.

Thank you for the reply. One more question though.... it has occured to me that I do not know where the timing chain went! IF... it broke, should it not be all crunched up at the bottom of the cover putting the crank shaft in a bind? or... at least making a whole bunch of noise rattling around inside? there is none of that... the engine turns like all get out ( as if no spark plugs in it, no compression ), does this engine have nylon gears ( I hope...) that have stripped... the more I consider this, the more I think that the cam shaft itself may have snapped. BUT, to me that is kinda wierd. I have NEVER heard of that happening. I guess this weekend will tell the tale. I have a 6" puller at work that I have been told I can use if it will fit. Will a 6" puller work on this motor? Thanks
Bill (GreenDragon51) Craig

The factory timing gears were nylon (assuming a previous owner didn't replace them.) You'll be taking off the water pump and then the timing cover behind that. To remove the timing cover the front two oil pan bolts have to come out. The reason for this is that the timing cover is over the first few inches of the oil pan. Any of the smaller broken parts would have fallen down into the pan. Since it is an excellent idea to change the oil after a timing cover break due to the coolant that will leak down into the oil. Do yourself a favor and drain the oil before starting the job. With the oil drained and the timing cover off it is most of the time possible to look into the pan (with a very bright light) and look for broken pieces. Those tools where you push one end and the other end opens up to grab little things is perfect for grabbing little pieces of broken nylon gears. Of course none of this is necessary unless leaving those pieces in the pan are going to bother you. There is no risk of them causing a problem since the pickup tube has a screen, then there's also the oil filter which will filter out anything that might pass through the screen.

Based on the "pop" you heard my gut feeling tells me you're going to find that one of the two gears snapped and all of the pieces will be large and right in front of you for easy pickin'.

Oh, and if you want to confirm if it's a snapped camshaft or not. Just pull all the plugs and put your thumb over each plug hole while cranking the engine to feel for compression. If any cylinders have compression the camshaft snapped. If none have compression it's the timing chain. The one exception is if the camshaft snapped between the timing gear and the first cylinder. Even in that case the timing cover has to come off to confirm. The only reason to know ahead of time if it's the camshaft is to have the extra parts on hand for the job. But in any case, that timing cover has to come off for either problem.