UPDATE: Yes Spark, No Start, 94 Legacy

[Sonicfrog]

I finished putting "Red" together, but it won't start. First off, I rechecked the timing via the belt, and some gemlins got in there and screwed it up - it was way off on the crankshaift. I know it was gremlins because I could NEVER make a mistake like that! So, I fixed that, but it still won't start. Turns out I have no spark. What are the usual culprits? Here is what I have checked so far:

 

I checked the lead to the magnetic sensor at the crank pulley, and it has continuity (I did have to splice the wires leading to that sensor and hopefully I connected the right ones).

 

I swapped the coil with a spare from the newer engine.

 

Went under steering to connect green jumpers to check codes, and found the jumpers already connected, which suggests the previous owner may have had the same problem, or he drove around with it like that.

 

At this point, I'm leaning toward a dead ECU. But I may be missing something, like a fuse or something simple. Anyway, I'm done for the night and will check back in the morning.

 

PS. How does that coil know which plug to send the spark to? There are only three wires going to the coil. Logic dictates there should be four, but since the thing is ccomputer controlled, it is operating using greater logic than I could. Also, are the cooling fans supposed to cycle when the key is in the "on"? Scratch that last question. Since I disconnected the green leads, the fans don't cycle anymore.

[nipper]

you need an analog meter. Check the heartbeat on the cam and crank sensors (its an AC signal). Thats where you start. Check that the sensors are clean and that all the teeth are on the crank and cam.

 

I dont remebr if you have an ignitor, if you do make sure its getting power.

 

nipper

[OB99W]

[...]PS. How does that coil know which plug to send the spark to? There are only three wires going to the coil. Logic dictates there should be four, but since the thing is ccomputer controlled, it is operating using greater logic than I could.[...]

Each coil in the pack fires two plugs at a time (they're "paired" in series), using the "wasted spark" method. The three wires you're referring to connect to the two coil primaries; the center one is common to both. When a cylinder is on a power stroke, its paired one is on an exhaust stroke. Only a few kilovolts is "wasted" jumping the gap in exhaust, leaving most of the rest for ignition of compressed mixture in the other cylinder.

 

This may help with diagnosis http://endwrench.com/images/pdfs/DirectIgnition.pdf , but the info on coil primary and seconday numbering and resistance is incorrect. See http://endwrench.com/images/pdfs/IgnitionCoil.pdf for the correct coil terminal identification.

[Sonicfrog]

OK. I DO get spark out of ingition coil, BUT only at the moment when you stop cranking the motor. I connected the black code plugs, and the check engine light blinked on / off, with no code. I then dissconected the cam sensor, cranked the engine, and I got a code 11. So the cam sensor circuit is OK. After reconnecting the cam sensor and clearing the codes, I then checked the the crankshaft sensor in the same fashion - no codes. So, I'm leaning toward a bad ECU circuit controling the cranksensor and spark. I will drop down to the J-Yard and pull another and see where this goes.

[OB99W]

OK. I DO get spark out of ingition coil, BUT only at the moment when you stop cranking the motor. [...]So, I'm leaning toward a bad ECU circuit controling the cranksensor and spark.[...]

From your description, it seems that there's no switched pulse getting to the coil primaries. Do you have a voltmeter? If so, you should probably trace the problem back, as described in the EndWrench link above. (Nipper mentioned the igniter.) Yes, the problem might be in the ECU, but there are possibilities other than that and the coil.

 

By the way, was the engine transplant a direct, exact replacement? Did electrical components just plug in, or was wire splicing or anything of that nature necessary?

[Sonicfrog]

The Crankshaft sensor was slightly smaller on the newer engine, so I did splice that one in. But even if I unplug it, the ECU still won't throw a code for a bad CKS.

[Sonicfrog]

UPDATE: Got the new ECU and ignitor from the junkyard. The car still isn't running... BUT, a few things are resolved. I now have spark. If I unplug the CKP sensor, I do get an error - BUT I'm getting an error of 1.3, which is the CAMSHAFT position sensor. I wonder if the two sensors are wired into the wrong harness? When I put everything back together, the white CKP harness was on the top and the gray CMP harness was just underneath on the harness bracket, mounted at the back of engine near the tranny. I also now get a 4.9 code - MAP sensor.

 

Have run out of time to work on the car today. will attack it again in a few days.

 

PS. Curious, would it make a difference if I pulled the ECU from a car that has a different tranny in it? I pulled one with the same 5 speed tranny as mine, but different year. There was a 94 in the yard but it was an auto tranny, so I went with the tranny match instead matching the year.

[nipper]

If the sensor is dead, it wont throw a code. If it is dying it will throw a code. It's one of those odd things of the OBD system. thats why i say its a tool and not the definitive answer.

Check them both for heartbeats.

 

nipper

[Sonicfrog]

If the sensor is dead, it wont throw a code. If it is dying it will throw a code. It's one of those odd things of the OBD system. thats why i say its a tool and not the definitive answer.

Check them both for heartbeats.

 

nipper

 

Will do. Thanks.

[OB99W]

UPDATE: Got the new ECU and ignitor from the junkyard. The car still isn't running... BUT, a few things are resolved. I now have spark. If I unplug the CKP sensor, I do get an error - BUT I'm getting an error of 1.3, which is the CAMSHAFT position sensor. I wonder if the two sensors are wired into the wrong harness? When I put everything back together, the white CKP harness was on the top and the gray CMP harness was just underneath on the harness bracket, mounted at the back of engine near the tranny. I also now get a 4.9 code - MAP sensor.

 

[...]

Doing engine "mix and match" with different models/years/transmissions/ECUs can make finding a no-start problem difficult. If you're not sure wiring is correct, checking sensors should be done at the ECU end, in order to verify that output is getting to the proper input. See page 5 of the "Direct Ignition" PDF to identify the difference in the signals.

[Sonicfrog]

I talked to the dealer yesterday, and ECU's are NOT compatible across transmision or year differences. I would need to get an ECU from a car with the same tranny, and the manufacture date would have to be after 06/03.

[Sonicfrog]

Since the ECU I got from the boneyard was not the right one, I reinstalled the old one, plus I checked the original CKP and CMP sensors for signal generation, they passed, and I reinstalled them on the engine. I now have spark. I have gas (checked the plugs). I have no codes. But it still won't start.

 

When I get the chance, I will re-examine the timing... again, just to make sure I didn't screw that up again.

 

This car will run... I swear it!

 

UPDATE: OK. I think I know what's wrong..... ME!!!!! I was checking some of the archives here on USBM and found this enlightening thread. I now know I have been making a stupid, STUPID error. When I timed the cams, I used THE ARROWS for timing instead of the little marks.:banghead::banghead:

 

This explians why I had such a hard time fighting the cams when I was setting the belts. They kept trying to advance to the right position, and I wouldn't let them. It's getting late here on the west coast, but I may just go out to the garage and fix this once and for all!

[johnceggleston]

I talked to the dealer yesterday, and ECU's are NOT compatible across transmision or year differences.

 

i don't believe this is entirely correct, otherwise you counldn't put a 95 ej22 into a 97obw without swapping the ECU.

 

it sound like you may have found your solution, congratulations. how about swapping in the 'other' ECU after you get it runnig just to see if it will work.

[OB99W]

[...]

UPDATE: OK. I think I know what's wrong..... ME!!!!! I was checking some of the archives here on USBM and found this enlightening thread. I now know I have been making a stupid, STUPID error. When I timed the cams, I used THE ARROWS for timing instead of the little marks.:banghead::banghead:

 

[...]

Obviously, you're not the first to fall into that trap, and likely won't be the last. For some deja vu, see this thread:

http://www.ultimatesubaru.org/forum/showthread.php?t=64923

 

The '94 isn't an interference engine, so no damage should occur with it mistimed. However, you mentioned this being a "newer" engine; how much newer?

[Sonicfrog]

The newer engine is an OHSC. It's my understanding the EJ22's became inerference when they swiched the the OHDC design. I'm pretty certain the 91 ECU won't work because the wiring going to all the sensors are connected to different terminals than the 94 version.

[OB99W]

The newer engine is an OHSC. It's my understanding the EJ22's became inerference when they swiched the the OHDC design.[...]

Not quite. Rather than explaining, I'll let Ferret's recent post quoting the FSM (Factory Service Manual) speak:

http://www.ultimatesubaru.org/forum/showpost.php?p=604858