Okay, this is a customer's car that I've been trying to diagnose for a few days now.
quad cam 2.5, 1996 legacy. Assuming it's an ej25D (Pardon me I'm more of an old school EA guy)

Anyway, I've checked compression on both pass cyls and the front driver's side cyl. All checkout (+120 PSI)
I have spark on those 3 cyls as well.
I've checked the timing using the attached diagram, all that checks out. Now the alignment marks that point to eachother on the intake and exhaust cams are off a little bit, but I've read that that's normal and the tooth count is correct.

 

So I'm stumped . It will occasionally fire on what sounds like 2 cylinders, and while cranking when I let off the starter it will also occasionally backfire out the intake.

I'm under the impression that even if that last cylinder had zero compression and/or fuel/spark, it should still fire up and run on 3. I can't get it to run but for maybe half a second, and very seldom.

Looking for some direction here, thanks in advance.

Timing diagram

still kinda seems like either timing or a sticking/dropped/cracked valve.

 

hoping someone else comes along with a good idea

 

did this begin after fueling? I have recently seen bad fuel causing problems.

 

interesting

Hi,

Did you check for stored CODES? '96 is OBD2/OBDII so a scanner will hook up to the port.

GL,

Td

Shot some starter fluid in the intake?

 

Definitely has spark?

 

Like WT said, check for codes.

Sorry I haven't worked on this car in a few days now. Customer had it towed in so I don't know about recent fueling. Ether with the backfire is a bad idea, but I tried it anyway and it went as expected (boom).

I'll check the codes tomorrow I can't remember what they were last time I pulled them.

 

I do know this car has a blown headgasket and they've been driving it like this for a few months now. I can see a sticking valve doing this, I'll have to break out the camera and look. If the exhaust valve is stuck that would explain my backfire and the good compression. Thanks for the ideas, I'll keep this updated.

Stuck or bent valve, put a dollar bill up to the exhaust tail pipe.  If it sucks back against the pipe when running you have an open exhaust valve.  Stuck or bent.

Won't run, but I'm going to turn it over but hand tomorrow and check it with the scope.

Kinda sounds like timing is off.

Running on a bad hg=bad juju. If it severely overheated it could have siezed, and broken a cam

The motor spins, I've rotated it many times but hand while I was checking the timing marks. Timing marks are all spot on (all friggin like 8 of them,jeeze!)

Didn't get a chance to check with the scope yet, gotta push it into the shop first, been too cold out.

I apologize if you've triple checked this but, on the crank sprocket, never use that triangle/arrow on the front, you need to use the 'dash' line on the tab at the back - line it up under the mark on the boss for the CPS.

 

 

really hoping it's a timing mistake, much better than something internal.

No apologies necessary! Thank you for the tip, I'll triple check the timing next time I work on that car. That's exactly why I'm here, for help!

This timing is a far cry from an ea82 you know what I mean?

The DOHC engines are kind of a pain. Sohc are much easier to deal with

Well, fairtax, speaking of that;

 

My boss and the customer have decided to just yank the motor and replace it with an ej22.

 

So I have a new question. This car is a 96 legacy outback wagon, with dual port exhaust and I'm assuming obd ii computer.

 

I am obviously going to need a dual port 2.2 so that leaves me with the phase one ej22s, but were any of those obd ii? I'm wondering if I'm going to need a new ECU+harness or if there's a way to use the existing one. I understand the ej25 intake won't bolt onto an ej22?

Ideally you'll want a 95 2.2 with EGR. Drops right in and everything plugs in exactly the same.

You can use a 96-98 2.2 if you get the single port y-pipe with it. Again, needs to have EGR to keep the CEL gremlins away.

 

The hoses for the evap canister might hook up differently, but those are easy to modify to work.