symptoms and possible problem, need some help

[Andy93ss]

Whats up folks, what I have here is a 93 legacy ss wagon, bone stock. So about a week ago the problem started, driving home from work and I dont recomend doing this but I hit the govenor and after a loud pop and let off throttle everything seems ok so I continue home at non warp speed. when I stop I notice boost gauge is low, fluttering at 10Hg at idle, bouncing from roughly 9 to 11. On top of that when I hit about 5 psi engine starts to shudder and popping starts again coming from the exhaust continiously until I let off the throttle. I checked the vac lines I could get to, all looked fine. Then get one of the spark plugs off and the end is completly rusted. I assume that is at least part of the problem and after testing the coil pack come to find out primary resistance is not in spec. Reading .9 to 1.0. Now I have looked and cannot find a difference in listed specs for the coil pack on an ej22t vs ej22e if there is indeed a difference. So if they are the same I think I found the problem. Still have compression test and check rest of plugs to do. So guess my biggest question is are the specs for the coil pack the same as in reading .7 ohms primary resistance and 10 to 13k ohms secondary resistance. Also if indeed this is the culprit could it cause the low vac reading at idle and rough idle?

[BSOD2600]

One of my threads somewhere... I found out that the FSM specs for the coil pack primary and secondary numbers are switched -- bought a new OEM one too and verified.

Maybe your timing jumped a few teeth?

[Andy93ss]

I was wondering if I had jumped timing.

Also if the # are switched I still went by what the readings were with the corresponding # that was closest. either its 13k or .7, huge difference. Im getting 12.5k ohms when Im testing through the 1-2 and 3-4 plugs on the pack and .9 to 1.0 ohms on the 3 wire plug. Manual says 10k to 13k spec and .67 to .73 respectively, roughly. not alot off spec at .7 ohms so Im wondering if this is really the problem. Either way Im getting a new coil pack today.

Now I havnt checked timing on the subie yet but from looking through the manual I need to take off the crank pully to get the cover off to see the timing mark. Really? Is there is no other way to check?

[Legacy777]

Yup, you need to remove the crank pulley to get the timing covers off.

[Andy93ss]

So out looking for a coil pack, no luck which turned out to be some good news. Found out a few things:

1: this post is in the wrong section

2: all cylinders are getting fuel and spark

3: compression test revealed the following:

cylinder 1: 150psi

cylinder 2: 150psi

cylinder 3: 150psi

cylinder 4 0psi

Turns out spark plug on cylinder 4 melted as well. I did take a peak inside and the piston is still moving giving a little peace of mind. At this moment Im not sure what I am going to do. Taking the head off is the most logical "next step" but Im just frustrated and need a night to take this in.

[impreza_GC8]

Wow so what happened to cause that loss of compression?

[Andy93ss]

I only have guesses right now until I can get the head off and see the damage first hand but from the looks of it I detonated or pre ignited at fuel cut, melted the spark plug and either there is a hole in the piston or I have some nasty valves. Trying to get motivated right now to get this project underway.

[H4_Deucer]

Do a leakdown test and see if your loss of compression is from the valves or if its down the crank case.

[Andy93ss]

Heads coming off tonight so I should know by tomorrow.