I have a 1994 bmw and injector #5 does not inject fuel into the cylinder what it could be?

I have change the injector from piston 1 to the 5 th and still doesn't work. the car has a lack of power when driving it, since its only working with 5 pistons.the check engine is on all the time even if i disconnect the battery for a long time.i took the car to an autoshop and they said it was the knock sensor so i replace it and still doesn't work.i change the air flow meter but the other day i changed the computer for another one that i have an the check engine light turns off but the car wont turn on because it has something broken in it, if you guys think the ECU is the problem i buy it if you guys think thats not the problem can you help me what it could be.....I have a 1994 bmw and injector #5 does not inject fuel into the cylinder what it could be?Does it have to knock you up side the head...replace the injector%26gt;
I have a 1994 bmw and injector #5 does not inject fuel into the cylinder what it could be?
check your compression
I have a 1994 bmw and injector #5 does not inject fuel into the cylinder what it could be?
You'll need to check the injector. The tool that is used to diagnose this is called a noid light. You disconnect the connector at the injector. Connect the noid light to the connector. If the light flashes, the injector is either bad or dirty. If the light doesn't flash, there's a problem in the fuel circuit. With the car you own, it may be better to take it to a shop that can diagnose your problem. If you change the injector and that's not your problem, you'll waste more $$ than it would have cost to have it repaired by a shop.
Get rid of that p.o.s. kraut clapper and buy something else. If you swapped the injectors and #5 is still not working then check the wiring harness and see if the injector is getting signal at the proper pulse width. If not replace the ecu with a %26quot;non broken%26quot; one. A knock sensor and air flow meter have nothing to do with the injector . Everything gives a signal to the ecu, Then the ecu decides how long to open the injector. Pretty simple isn`t it. If the ecu decides not to open 1 injector then it is either that injector or the electrical signal from the ecu. A real bmw tech with a proper scanner can tell you. but that would cost more than the car is worth.