Sounds like the car is still injected. In that case, I would check:
- The head temp sensor. This should be near the #3 spark plug, one wire plugged into a square box connector. Unplug it, and see what the resistance is to ground, both cold and after the engine is warm. Should be around 3K ohms cold, around 100 ohms warm. If it's unplugged or very high resistance, you'll get a way way too rich mixture.
- The fuel pressure. Should be 29 PSI while the fuel pump is running. Too high will result in a rich mixture.
- The MPS. Should hold a 15" vacuum for ~10 minutes without leaking down. Use a hand vacuum pump with a gauge (e.g., MityVac) to check. You can suck on the hose to the MPS if you like (better make it a new or at least clean hose, YUCK!) but that will only tell you if it's really really really bad. A blown MPS will result in a rich mixture as well.
You can also check Brad Anders' D-jet page, at
http://members.rennlist.com/pbanders . Just about everything that anyone currently knows about this EFI system is on that site.
--DD