WTF? 2000 Sport starts but dies - HELP!

I can't believe this! Thought I had it fixed.

(see my other posts on 2000 Sport won't start) I replaced the ASD relay this afternoon, started up fine, ran for about 20 seconds and then just cut out dead. Cranked and cranked but no fire. Turned the ignition on and off a bunch of times and then tried again and it starts. Runs for another 20 seconds and then quits. Did this three or four times. Cuts out whether I was revving the engine or just letting it idle.

As of 5 minutes ago, cranks and cranks but no fire. Turn ignition on and no juice to the injectors with the brand new ASD relay. With ignition on, pull relay and jumper the 30/87 pins and I get juice, but still won't start. If I turn off the ignition, jumper the pins, and turn it back on, the leak detection pump for the EVAP system runs and runs, but the engine still won't start.

Does the ASD relay send power to anything besides the injectors? The 30 amp fuse seems like alot for just the relay and injectors. Is there anything electrical downstream of the relay that could have failed and caused the ASD relay to fail/arc out? I had no previous problems with it shutting down like this.

Any ideas? Is there anything else that would make the ECU shut down like that? I'm at a complete loss here. There must be something that the ECU detects and then pulls the plug on the auto shut-down relay. And NO CEL or ERROR CODE! (Someone at Chrysler should be shot - I don't care, anyone - okay, well, start with the programmers...)

HELP!

Low oil pressure?

No, I don't think thats it. The pressure comes up after about 2-3 seconds of cranking and gets up to 30-40 psi.

I just went out and checked the ASD relay again. With ignition on, I pulled the relay, re-inserted it, and got a "click" from the relay. OK, right? But I checked the injectors and no juice at the injectors.

So I pulled the relay and inserted a test light across the 85/86 sockets that power the coil and only got a brief glimmer. Pull the light out and re-insert and again only a brief glimmer. Tried the relay - click, click, click. Tried the light again - brief light then dies out.

So... bad connection or broken wire between the ECU and ASD relay???

By the way - I had the Jeep up for sale, everything seemed to be working fine. One guy comes to look at it, we take it for a drive and "surprise", the aux fan is shaking like hell. I pull the fan and find four big fingerprints right where the fan shroud is freshly broken. New fan - $100. Same guy comes back to look again, I drive and everything works fine, he takes another look under the hood, fiddles with this and that, tells me the ice-cold A/C will need work, how low can I go... 3 days later I go out to start the Jeep and it cranks but no fire. Anyone heard of any "quick and dirty" tricks to disable a Cherokee like this?