Should have known better, injectors

[waynep]

Hello All:

Well against my better judgement and recommendations on this board I purchased eight $25.00 injectors that look very well made but are shurely from China.
Replaced the easy four on the driver side and I never noticed befor but it now white smokes on startup. It seemed to run better at first but now seems to run rougher.
Does this sound like bad injectors? I am thinking about buying "good ones" and replacing the harder ones with the real thing.
Is the white smoke on startup a typical bad injector issue?
Maybe I should put the old ones back in and see what happens?
Suggestions appreciated.
1997 3/4 T subway. 175 K miles.
Thanks, Wayne

[DmaxMaverick]

You won't really know much unless all 8 are replaced. 4 worn out and 4 new (even new junk, if they are) leaves a very unbalanced engine. Your old injectors, even if way past their useful life, were a lot more consistent than the combination you have now.

I suggest withholding judgment until you get a good run with all 8 new. It may also take some time to get out all the air and break in new injectors (this can vary, depending on the quality of build).

[rustyk]

I've only had to replace injectors on a couple of engines, but I always have them tested for pop pressure and spray pattern. Only one ever tested marginal (for a Nissan Maxima 2.8L 6-cyl), but it was worth the money. One for the 6.9L Ford had a nicked thread, but the shop was able to chase it and then test it.