No Injector Pulse EJ22 1992 Leg Wag

[Yamagata]

Hello,

I have a 1992 Legacy Wagon, EJ22, AWD, N/A. A few days ago the motor simply didnt fire up and has not fired up since.

The wagon has not had any motor work done to it for over 3 years. No recent accidents either. Its been a great running & reliable machine. I maintain it myself.

What I've checked:
-Fuses (both under the hood and Under the dash)
-Ran the codes (24, 11, 13)

-Inspected crankshaft position sensor. Tested sensor and found it to be working and within spec.
-Inspected camshaft position sensor. Tested sensor and found it to be working and within spec.
-Checked Air Control Valve (code 24), and found it to be within spec.
-Inspected Coil, All plugs are getting spark and sparking properly when the motor is turned over.
-Inspected Fuel Filter. Good volume of fuel flows through filter, and filter changed a year ago with other filters.
-Fuel Pump. I did not have the proper gauge to test fuel pressure, so I replaced the fuel pump with a brand new pump. Fuel filter sock is new too.
-Tested fuel injectors, all 4 have proper ohm reading.

What I've discovered is the fuel injectors are not pulsing.

-I tested each electrical lead and found that there is only 3V at each injector. When the motor is cranked over the voltage drops to 2V.

I have another Gen 1 Legacy Wagon (1994). It is a good runner. So I pulled the ECM from the 92 wagon and installed it on the 94 wagon. The 94 wagon ran great! ECM is good.

I installed the 92 Crank and Cam Sensors on the 94. The 94 wagon ran great! Good sensors.

The 94 Wagon has 10.5V at each injector. And when the motor is running, the voltage increases to 11V.



So, I dont know why I'm getting low voltage at the injectors. I've run out of ideas.

Any Suggestions??

Thanks

[Yamagata]

UPDATE:

I read a post about cleaning the Idle Air Control Valve (code 24).

I removed the valve and found that it was sort of dirty, but the valve moved with ease. after cleaning it retested the ohms.

Pins A - B - C

A + C = 19ohms
A+B = 9ohms
B+C = 9ohms

These values are identical to the IACV found in my good running 94 Wagon.

I put the IACV back on the motor - No Change!

I dont know what is causing the Low voltage at the injectors.

Any suggestions??

[mike-tracy]

Verify the timing is on. Also, I didn't see you mention it, but did you use the good battery from the 94 to rule out that as a factor?

[Yamagata]

Verify the timing is on. Also, I didn't see you mention it, but did you use the good battery from the 94 to rule out that as a factor?

Thank you for your reply.

I dont feel that I need to check the timing marks. The reason for this, is that when I spray fuel into the intake manifold, the motor runs killer. No back fire, no lumps, no snorts. I'd think that if the timing was off, I would expect to have a motor that would run poorly or not at all.

This motor simply lacks one key ingredient and that is fuel. For some reason the signal to the injectors is not there.

The battery in the 92 wagon is actually a better quality battery than the battery in the 94.

The low voltage at the injector connections is what puzzles me. The 92 only has 3V when the key is in the run position, and the running 94 has 10.5V when the key is in the run position.

Does anyone know if there is a ground that could effect the voltage at the injectors?

Thank you for your suggestions.

[Yamagata]

OK, so we have some more hints to the problem of the lack of Injector Pulse.

We have a running 94 Legacy Wagon and compared readings from it with the readings from the 92 wagon.

What we found was that the Electrical voltages at the Fuel Injectors are different.

fuel-injector-voltage-test-002 by R H, on Flickr

Here you can see the readings from the 94. We read the voltage in 3 ways

Key in the RUN position.
1 - BLUE READING, (+) & (-) placed on each electrode, voltage = 10.3V
2 - GREEN READING, (+) placed on left electrode, (-) placed on ground, voltage = 12V
3 - RED READING, (+) placed on right electrode, (-) placed on ground, voltage = 0V

We assume that the 94 readings are normal.

Here are the readings from the troubled 92 Wagon that wont run.

fuel-injector-voltage-test-001 by R H, on Flickr

1-BLUE READING = 3.3V compared to 10.3V on the good 94
2 - GREEN READING = 12V just like the good 94
3 - RED READING = 9.5V compared to the 0V of the 94

I dont know why there is a difference, but are starting to suspect a short or bad ground.

There are some other tests we are going to do, and I'll follow up with that.

Any suggestions or similar stories are welcome here. Something you add, might make a connection.

Thanks

[Yamagata]

I'm happy to report that the problem has been solved.

Unfortunately the solution was sort of a mystery. I was checking continuity between all harness subsections.

The electrical connection between the motor and the firewall, I think, is where the problem lay. I think it wascorroded connection, or a wire that had been pulled out slightly when trying to change spark plugs, rats doing pull ups on the harness...WHO THE F. KNOWS!!

But when I plugged the harness back in, after checking everything I could think of under the dash, I double checked the injector connections. This time they read normal. 12v and zero volts. I just knew the motor would fire back up.
Moral of the this story is, if you dont have injector pulse, and the readings at the injector connectors are weird, you probably have an incomplete circuit somewhere. Unplugging and repluggin wires back together might actually fix the problem.

Also, a great site I found lots of useful info was

http://www.shoptalkforums.com/viewtopic.php?t=136053

A guy installing an EJ22 into a baja bug. His write up was better than anything I read on this site, USMB or any other subaru related site. Thanks VW DUDE!.

[Legacy777]

Thanks for the updates and troubleshooting.

I would agree it sounded like a bad ground which may have been caused a connector not plugged in all the way.