stupid question

[JZProwler]

Ok, my CEL has been on for a while now...and i just got my car back from the tranny shop...have a new transmission put it..there were no gears left on the pinion(i think thats what its called...the gear that the axles go into). Alright, so for the shop to the let the car leave, or so a diagnostic or whatever, they cleared the code...and i've known it to only be P0304 which is cylinder 4 misfire, and thats the only code its been throwing, it of course came back on on my trip home and, well i'm rather confused. I have new spark plugs, cap and rotor and i believe my wires to be good, if anyone knows what resistance they should be, i can check that with my awsome DMM. are there any other possibilities as to what could be causing just that one code, i hate to say it, but im kind of stumped. could it be actual damage to the engine causing that? I never heard anything break, or any unusual noises, and i check my oil weekly just because i know i burn a bit.

My pro is just as slow as every other Z5 manual, but i want to at least get all four cylinders of our brutal double digit horsepower working and not waste the gas.

[Project Protoge]

check to make sure the injector is firing properly.

[JZProwler]

ok, how would i go about checking that? would i pull the injector out and use a DMM or just listen to see if its clicking (which means its functioning correctly, the solenoid is moving like it should, right?) I just want to make sure i dont overlook something simple...and thanks for the suggestion

[pigeon]

misfire code?
do a compression test and post the #'s

[JZProwler]

if i can get my hands on a compression tester i'd be happy to show how much vacuum my engine is giving (yes, i did that on purpose, knowing that it must be that bad ) . Kinda funny, i go to a school for automotives and dont have a compression tester or access to one =\

[JZProwler]

ok, im at work now..on my break i did a quick test that may be useless...i turned my car on, and then pulled the plug for the #4 injector and the car became a little unstable, but not much of a change. then i put that back and pulled the plug for the #1 injector and the car began running very rough...same thing with #2 and #3. now, this would lead me to beleive it could be the injector, but is it possible that since the computer is sensing a misfire, it could be disabling the injector somewhat on its own, or is that not in its abilities? I'm not too knowledgable on ECUs and computer systems..but luckily the next 3 weeks in school is advanced electronics so i will have a clue

[pigeon]

do a compression test man... i got both fingers pointing at a valve not seating properly

[Project Protoge]

Like pigeon said, your next step is a compression check. If compression is low you probably have a valve train problem but if not then you either have a spark issue on cylinder 4 or a dirty or bad injector.