Help Please - 74 1.8 L Jet Issues, Either missing on #4 or won't start at all Options

[SteveL]

Basic Info:
74 1.8 L-Jet
Just installed new SMP injectors
Fuel pressure gauge installed.

I installed new injectors on 1 & 2 yesterday to replace a leaking injector, and it ran really nice after - better than before, leading me to believe that the old injects weren't 100%.
So, today I installed the other 2 new injectors on # 3 & 4 on passenger side. Now won't start at all. Fuel pressure gauge shows 36. I checked all fuel lines, all injector connectors, all vacuum lines. All looks good. Still no start. Time to step away, go get lunch.
Hour later, try again - she starts but backfiring really bad through exhaust. Check all vacuum lines again, all look good. Start it again, starts good, but is running rough. Idle is way high, adjust idle screw as it warms up to get idle down to 900. I think I may need a new cold start valve. Once warm, steady idle at 900. give it a little gas, and hold steady around 2700 rpm and it backfires through exhaust. To see if a specific cylinder is missing, I unplug wires one at a time. Pulling #4 makes no difference. #4 isn't firing.
Plenty of spark at the wire. I THINK the fuel injector plug tested ok. Took out injector and pointed it into a bottle. Had the lovely wife crank it over, no gas going into bottle.
AHA - bad injector. re-install old injector. Now no start at all. Check engine bay, and the hose on the old injector has also sprung a leak. WTF!!!!

Also, when testing the fuel injector plugs with a test light, one side was always hot, the other side would be lit with key on, then flash when engine cranked over.

Deep breath. Reinstall the new SMP injector again. No Start. Sit down at desk and throw myself on the merciful wisdom of the club.
Help me Obi-Wan Kenobi's, you're my only hope (kids are watching Star Wars in the other room...).

(IMG:style_emoticons/default/headbang.gif)

[djway]

there are some really good articles on The Samba about L Jet. You can find information for every single pin and part and how to test each. They also include charts of symptoms and where to look first.
When I got my 914 a few years back the only thing that worked was going through the list one by one and ticking off possibilities. When I recently built the big motor for my NotchBack I used the articles first to make sure I was getting the readings I needed at every point then started tracking down each part from there. My AFM was not even calibrated, I made it from several, so I was starting from Zero on a big motor. Eliminating one possibility after another winds up taking less time for me than shotgunning the approach.