Having a bad TPS on any van over 150k miles is almost a given............but you just had your engine rebuilt. Are you saying they put an old TPS on a new engine? After rebuild typically comes tuning, and that includes checking codes........unless they skipped all of that they should have picked-up on that and changed it. All this is beside the point though as a bad TPS won't prevent the van from starting. You need 3 things for a gasoline engine to start: compression, fuel, and properly timed spark. The other things (TPS, o2 sensors, cold start equipment, temp sensors, etc will only affect how well it runs, emissions, and economy). For 88 - 89 vans, no spark usually results in trouble codes 12 or 14. Since you don't have either of those I'd skip past checking spark initially. Sudden compression problems are rare (and will make the engine sound different during cranking), so unless you noticed a fast & unusual cranking noise, I'd start out by checking the fuel. You can do that by jumping the "Fuel Pump Test Connector" & turning the key to "Run". At this point the fuel should be flowing and you can hear it if you listen inside the engine bay. If you can't hear it then you have a fuel problem. It's a simple test and only takes a few minutes. It's outlined several times in the forum, so just do a search using the phrase "Fuel Pump Test Connector" and several helpful threads should pop-up. If it's not the fuel system, then go back and check for spark.

To troubleshoot a dead van, here's a few threads that should help:

http://www.toyotavantech.com/forum/s...p-for-a-newbie!

http://www.toyotavantech.com/forum/s...p?631-dead-van

http://www.toyotavantech.com/forum/s...-cap-and-rotor

There are several other such threads, just use the search feature. Good luck. Tim