Emergency, car overheating !!!

[speeddreamz]

Well, I picked up a 91' 240sx fastback recently and thought it was pretty clean. I had a 90 240sx fastback but it was all beat up looking so i sold it and got this one. Now, after it being very reliable for about 2 weeks I did a few minor changes. I was driving it today with no problems and decided to take off the power steering. I hate the way power steering feels, I can't feel the road. So anyways, I cut the belt and basically as far as I could tell it runs off the crankshaft, the powersteering pump and one extra pulley which is the adjuster/tensioner one, which serves no functional purpose except to put the belt on or off? So I cut the belt, that should have no bearing on the car overheating right?

I also put in a fuel injector cleaner by pyroil in my full tank of gas, because i forgot to do it when I changed my oil ? I am thinking that is the culprit I always thought the things were pretty decent, and wouldn't hurt the car.

Anyways, the car overheats so fast and it cools down pretty fast too when I have the engine off, I had the engine all the way up to high heat and turned the car off coasted 60- stop on the freeway and it cooled halfway down ?!?!?! I'm thinkin maybe my radiator is ok, but the fuel injector **** is bad?