compression or injectors?

allright, so my dad took my car to his friend who is a mechanic and his friend said that cylinder 2 has no compression.(i was like fucking duh, I have and injector out.)

But then he told me that the mechanic said that reason my injector doesnt work is because of the compression loss, and that I probably need a new piston and valve. I was like no the reason i dont have compression is because of the fuel injector, not the other way around. give me some feedback on who is right.

P.S. The mechanic says he doesnt work on DSM's and ill have to take it somewhere else.

At least your mechanic is honest that he doesn't work on them, because you are going to want somebody that does. Having your injector out would not hinder your compression at all. If it did, this would mean that your injector would somehow be engulfed in the ingnition process, and obviously, this won't work.

I can't understand why your injector would not work if there wasn't any compression. That have no correlation in that sense. It would just run like ass.

Depending on the severity of the problem, you could end up replacing not only a valve, but valve(s). However, in your case where you only have one cylinder as you say that doesn't have any compression, that usually doesn't directly indicate a valve problem. Not that you will rule out that issue all together, but generally, it has something to do with the piston/rings, or headgasket. Either way, you are going to need to pull your head, so you'll found out what's wrong somehow. Unfortunately from what I know, your both wrong.

If you are so inclined to do so, and should be, a leak down test is on order here. This will help you pinpoint your problem, and directions on how to do this are on www.vfaq.com .