What simple way to determine whether fuel injector is spaying gas or has a bad valve.?

Spark plug is firing. Fuel injector lead shows electrical charge. Compression is at 130. One mechanic says the fuel injector is the problem because not spraying gas. Other mechanic says fuel injector is spraying gas. Says the problem is a faulty valve. It appears that both are guessing. Fuel injectors cannot be taken out unless you take off the head. How do I decide which is the problem. .
What simple way to determine whether fuel injector is spaying gas or has a bad valve.?
Simple. You can get automotive stethoscope like this





http://www.sears.com/shc/s/p_10153_12605...





or just use a long stick. Touch one end of the stick to the injectors and the other end to your ear. The sound should travel to your ear. If all the injector are firing, they would all sound about the same. The dead injector will sound muffled or nothing.





But that only says that the injectors are opening and closing. It could still be clogged. In which case you should at least try fuel injector cleaners.








Good Luck...
What simple way to determine whether fuel injector is spaying gas or has a bad valve.?
That last one was a good answer! The only thing I would add to that is .. it seems like you had a compression test done because you report a 130 lbs figure, and that sounds nice and high. Are all of the other cylinders +/- 5 lbs off from that 130 number? What I am getting at is if you had a bad valve (leaking or bent, not seating properly, etc) then the compression will be lower for that particular cylinder.





So maybe you can rule out half of the equation right there. Of course you didn't say what model/year the vehicle was so we don't know if you can use a cheap Harbor Freight ODB-II code reader (just $39 and SO worth it), which might tell you the EXACT problem, right down to which injector is bad.. or if you're not burning all the fuel in X cylinder.





As the last gentleman recommended, buy a couple bottles of injector cleaner and dump them into your $80 full tank of gas.
Reply:fuel injectors can _ be removed from the cylinder head_ separately, fuel spray patterns can be checked buy any technician with suitable test rig. the compression looks ok!
Reply:One thing you might try is running your engine with one f.i. disconnected electrically at a time.


Either way, they're saying they think you have a bad injector. That might help to show if you do.


You didn't say you took your car to a mechanic.
Reply:if it has compression the same as the others it is not the valve, you can swap over 2 of the in jectors and see if the problem is the injector, then it would mis fire on the cylinder you swapped it to