Compression Problem

[SDS13COUPE]

Ok. These numbers are when the engine is running with a compression gauge on it. The problem is my #1 cylinder is being cancelled out for some odd reason. I would unplug the harness to the #1 injector and nothing would happen. I would do the same to every other injector and the engine would sputter and shake. At first i thought it was the injector so I got another rail with good injectors and swapped it on. Nothing. So now I check compression and with the engine cranking it reads 150psi evenly across all cylinders. So another tech that works with me suggested doing a compression test with the car running. These are the results.

Min.(Idle) Max.(Rpm Increase) Cyl.#50psi 110psi 175psi 150psi 275psi 150psi 375psi 150psi 4

So #1 obviously looks bad. So now is the fun part. What can it be. None of my co-workers have any knowledge about the SR20DET so it's hard to figure this out on my own. So i now turn to you guys for assistance. Please help me with this dilema so my car can go back to scaring unsuspecting passengers. I think it could be the valve springs on the number one cylinder because if the springs are worn or even worse broken that means the spring isn't closing it anymore the compression is. Any help is welcome. I might be getting to deep into this causing me to skip the basics so please help me. Any local help is more than welcome also. Thanks and this site is the sh*t. Peace


Modified by SDS13COUPE at 10:42 AM 11/8/2006

[SDS13COUPE]

C'mon guys. Someone help me please.

[Blown240sx]

what do you mean what could it be?

1. Bad Piston Ring (Pressure will build up in the crank case also burns oil when running)2. Bad Valve Seat (you will hear the air leaving through the exhuast or intake)3. Bad Valve Spring (same as above)4. Bad head gasket (Coolant mix with oil and should be a audable hiss of air around the head)

There now start looking