'88 7.5, won't run/start cold ??

Drove home fine, then wouldn't start. Got it started by pumping the throttle (I know, shouldn't matter with fuel injection, right?) but wouldn't run below about 1,000-1,500 rpm. (TPS?) Fiddled around with some broken/cracked vacuum lines while occassionally trying to make it run (warmed it up a little maybe?) plus had the battery disconnected for about 1/2 hr and it started right up and ran great. For 2 days. Same problem again now but no cracked/broken lines this time. Is there a cold start enrichment circuit that could be causing this? When I get it started it has minor backfiring out of the intake (while running at about 1,000rpm) makes me think it's running lean. I haven't tried to warm it up at this point to see if it will eventually run correctly.
Any ideas?? Thanks all,
Jeff.

Drove home fine, then wouldn't start. Got it started by pumping the throttle (I know, shouldn't matter with fuel injection, right?) but wouldn't run below about 1,000-1,500 rpm. (TPS?) Fiddled around with some broken/cracked vacuum lines while occassionally trying to make it run (warmed it up a little maybe?) plus had the battery disconnected for about 1/2 hr and it started right up and ran great. For 2 days. Same problem again now but no cracked/broken lines this time. Is there a cold start enrichment circuit that could be causing this? When I get it started it has minor backfiring out of the intake (while running at about 1,000rpm) makes me think it's running lean. I haven't tried to warm it up at this point to see if it will eventually run correctly.
Any ideas?? Thanks all,
Jeff.
Check your Fuel preasure regulator

I work on diesel trucks, not much automotive so help me out please. I bought a discount f/i pressure tester. I assume there are fittings to plug in to? Do you test before and after the regulator in order to diagnose the pump vs. pressure regulator? And what pressures should I be looking for? It's a friends rig so I can't remember if it has test ports on it. Thanks,
Jeff.