Nissan Repair: 91 Maxima poor performance, vacuum hoses, air plenum

Question
Von, I have a 91 Maxima that had a fuel injector which was opening up when hot.  I was going to order just one injector but I ended up ordering a matched set fron Autocraft direct.com for $55.00 apiece. These were remanufactured unit and the guy convienced me that I would be replacing these in the future so I should just get it done now. Well this last weekend I replace all the injectors and ended up with 2 of the new ones having a problem where they stuck open and flooded the # 5 and then the # 6 cyl. right after installing them. Now this engine ran very smooth and started instantly(when the old thermal injector wasn't open) but since I've put in these injectors (swapped out the 2 def injectors with 2 formally replaced injectors ) This engine doesn't idle as smooth and doesn't start as quick. It seems to be running rich, I smell fuel but don't see any leaks. It hesitates from off idle just a bit. It has 4 pink reman injectors and 2 of the pink with blue dot injectors from a previous replacement. I did notice that there is a vacuum dashpot which rotates a shaft that goes through the air intake plenum and controls a set of throttle plates. The dashpot doesn't seem to hold vacuum and it is mounted on the drivers side of the air plenum and has a short vacuum hose going to some type control valve. Could the TPS sensor be sending a full throttle signal? O-2 sensor saying too lean? I've replaced bad/cracked vacuum hoses and the airfilter. I know that this is hard to troubleshoot from afar but I appreciate any ideas. Yhanks, Joe      ps. I stopped credit card payment on the injectors and sent autodirect and email. I took the intake apart 3 times this weekend till I got the car to run somewhat right and I told them that a 33% failure rate was terrible. They want me to send them the def injectors and I will but after I get this car running right.

Answer
Joe,

I would send the injectors back and get another set from another source.  There is where the problem is with the starting and idle.  Also, be sure to check the connectors that plug intot he injectors to make sure you get good contact when you put the new ones in.  I am so cheap I go to the wrecking yard and buy up sets and pick and choose the ones that work good.  But, I am a nut when it comes to car and time is cheaper than money...