98 Forester Stalling, Dying, Intermittent Spark, to No Spark

[uncutchemist]

1998 Subaru Forester

 

I had recently replaced the front axles and after the first test drive, I started having the following issues. It should be noted that I did get my wires crossed to the front O2 sensor during the axle change. (Accidently got pulled and switched one of the grounds and power wire! Dohhh!! Didn't notice until after the following issues.)

 

Car was stalling and not getting power. During the stalling giving it gas through the pedal caused no response. (It would not run long enough to get it somewhere to get it coded for the check engine light.)

 

Tested fuel pressure and it was a little low at 28 psi.

 

Installed New Fuel Pump and Fuel Filter

 

After Fuel Pump and Fuel Filter change, the car still had the stalling and dying issues once warmed up. You can smell the fuel being injected so it is getting fuel.

 

The coil pack was getting intermittent spark. Tested spark using a plug wired to the coil against the engine. Bought a crank shaft sensor and ordered an ignition coil.

 

Installed New Crank Shaft Sensor

 

Still getting intermittent spark. Ordered new ignition coil. My diesel mechanic father in law fiddled with it a bit with a test light. (I've been told this is a big no, no after the fact.)

 

Now, car will not start at all. Now, there is no spark what-so-ever.

 

Still could not get anywhere to get it coded. So, I ordered a Vgate Bluetooth OBD2 reader and Torque Android App.

 

Installed New Ignition Coil

 

Did not resolve the issue. No start. No spark. After 3 attempts to start, battery died. Recharged battery. Checked codes. (Should have done this before the ignition coil install.) No codes, maybe due to disconnecting battery.

 

Installed Junkyard Igniter and Cam Position Sensor (Tried 2 different Igniters and Cam Sensors)

 

No change.

 

Tried reading stored memory codes by connecting black connectors under dash

 

No stored codes. ??Maybe from disconnected battery cleared ECU??

 

Connected Green connectors for Diagnostic Test Mode

 

The car will not start at all, so I do not think this will do much good, but I thought I would test it out.

 

This showed up the usual codes for this action: (Really don't think this was useful, but I don't know.)

 

P0130

P0136

P0500

P1100

P1101

P1120

P1121

P1540

 

Is my ECU fried?

How can I test this using a multimeter or any other test.

 

I'm freaking out, and I do not know what to do at this point. I have put in $150 so far, but it seems it is probably cheaper than a diagnostics at a repair shop.

 

I'll have to get it towed to a repair shop soon if I can't get it running.

 

Any help is super appreciated!

 

 

[Fairtax4me]

Hard to say if the ECU fried. Usually you'll have some codes for random stuff if that happened. Depending on what was disconnected/removed during the axle change you could have a loose ground connection for the ECU and that would cause major problems.

 

A test light won't hurt the coil or the igniter (ignition control module on the center of the firewall), but it may hurt the ECU if connected to wiring between the ECU and igniter.

 

How have you tested for spark? Have you checked with a spare spark plug or spark tool stuck in the end of one of the plug wires?

 

 

Ignition coil should have 12v on the center wire. The other two wires will pulse to ground which causes the coil to discharge the spark.

You can check these with a test light by probing the center wire and connecting the other lead to either of the outer wires. The test light should blink quickly as spark is commanded by the igniter.

If the test light stays On that indicates the circuit between the coil and igniter is shorted to ground.

 

 

Camshaft sensor will also prevent spark, but you would have a code for it especially if the engine will not start.

[uncutchemist]

Hey FairTax4me, thanks for the input. I met a Subaru technician and he is coming to look at it this weekend. I'm convinced at this point it is the ECU, but I'm going to let him put in his 2 cents. I will update as soon as I have it figured out.

[Rooster2]

 A used ECU from a yard is inexpensive, from what I have read on this forum over the years.

[MilesFox]

Check the MAF sensor

[uncutchemist]

I had credit at a local junkyard so I picked up a MAF sensor. No change.

 

I had it looked it by someone who supposedly knows Subaru's. He said he thought the ECU was bad. I ordered the ECU and replaced it. No change.

 

I re-installed the original ECU sensor. (Added this as an edit for clarity.)

Edited September 27, 2014 by uncutchemist

[Fairtax4me]

Go over the basics again.

Check all fuses, check anything that was disconnected unplugged or removed during the work.

 

Do you remember which wires (colors) got crossed on the O2 sensor?

Did you look to see if the wiring was damaged or cut up in the harness?

[AdventureSubaru]

98 forester still have the black fusible link? I'm calling link or fuse somewhere. In the engine fuse box, look for a 3 inch black wire. if you've got it, you may have your problem. When wires cross, it will fry and you will have a no-start. I have had this happen on two Subarus. Both because I was a dolt and installed a battery backwards in the dark.

 

if your car is too modern for fusible links, start checking/swapping fuses. I bet your answer is in there and not bad parts. We already know that wires got crossed, so chances are the fuses or links did exactly what they were supposed to do and blew up before more important things did.

[1 Lucky Texan]

disconnect the MAF. That should force the ECU to run on a 'stock a:f map'.

 

crank with the gas pedal on the floor - in case the engine is flooding.

 

If no improvement, then the issue is 'deeper' than a simple a:f problem. Timing or spark, etc.

 

as said, go back to basics including timing. Pull plugs to see if they are wet. measure fuel pressure. maybe crank while monitoring a vacuum gauge for stuck valves or major vacuum leak......

[uncutchemist]

Thanks to everyone who is posting and helping out. It is a big help in big ways.

 

 

disconnect the MAF. That should force the ECU to run on a 'stock a:f map'.

 

I had previously disconnected the MAF hoping it would start. No start, no spark with the MAF disconnected.

 

98 forester still have the black fusible link? I'm calling link or fuse somewhere. In the engine fuse box, look for a 3 inch black wire. if you've got it, you may have your problem. When wires cross, it will fry and you will have a no-start. I have had this happen on two Subarus. Both because I was a dolt and installed a battery backwards in the dark.

 

if your car is too modern for fusible links, start checking/swapping fuses. I bet your answer is in there and not bad parts. We already know that wires got crossed, so chances are the fuses or links did exactly what they were supposed to do and blew up before more important things did.

 

 

I did check for the fusible link. I don't have one. I do have fuse that is bolted in. It tested good with the test light.

I rechecked all of my fuses with the test light. They all checked good.

Relays tested well. (Switched them to the horn position and honk tested them.)

I light tested the fuses under the dash with a test light. They work fine.

 

 

Go over the basics again.
Check all fuses, check anything that was disconnected unplugged or removed during the work.

Do you remember which wires (colors) got crossed on the O2 sensor?
Did you look to see if the wiring was damaged or cut up in the harness?

 

There are three wires on the O2 sensor. One black and two whites. A white and black one was crossed.

 

 

This weekend I am going to pull off the intake manifold so I can see the wire harnesses underneath. I am going to follow the O2 wires and see if there are any melted or crossed wires.

 

After that I will pull off the timing cover and check the timing. I did pull it off to make sure it didn't snap. It is not an old timing belt, so I think it should be good. Then again, I don't fully understand what would cause it to potentially skip a tooth in the belt.

 

I will recheck the fuel pressure and figure out a way to test vacuum to the valves. (I don't understand how this would give a no spark, but I'll do it.)

Edited September 26, 2014 by uncutchemist

[1 Lucky Texan]

no codes stored/pending?

[heartless]

I don't fully understand what would cause it to potentially skip a tooth in the belt.

 

There are several things that can cause the timing belt to jump out of time

• a weak tensioner can allow slack in the belt, causing it to skip.
• damaged/missing teeth on the belt itself
• bad bearings on one or more of the idler pulleys
• water pump beginning to seize up/fail

the above potential issues are the reason most of the folks here will change all of the idler pulleys, the water pump, and often the tensioner with at least the second recommended timing belt change interval, even though the service manual does not call for it.

[ivans imports]

Check main engine ground on intake and power supply on bottom side of under hood fuse box also cam senser

[Dj7291993]

Did you ever try the test light on the coil, as suggested by fairtax4me?  Your engine needs air, fuel, spark, and compression to run.  You need to figure out what you are missing.  Spark is an easy one to check on these engines.  For fuel, you need fuel pressure/flow and injector pulse.  You can try supplemental fuel, like brake clean or starter fluid, to see if it will start on that.  Compression can be checked with a compression gauge.  If you are missing multiple things, check the things they have in common.

 

Like the others have said, go back to the basics.  And take a break if you need to.  You'll never make much progress when you're ticked off.

[uncutchemist]

Did you ever try the test light on the coil, as suggested by fairtax4me?  Your engine needs air, fuel, spark, and compression to run.  You need to figure out what you are missing.  Spark is an easy one to check on these engines.  For fuel, you need fuel pressure/flow and injector pulse.  You can try supplemental fuel, like brake clean or starter fluid, to see if it will start on that.  Compression can be checked with a compression gauge.  If you are missing multiple things, check the things they have in common.

 

Like the others have said, go back to the basics.  And take a break if you need to.  You'll never make much progress when you're ticked off.

 

I did test light the coil. That is why I originally changed the coil thinking it was the issue initially. I tested lighted the cam position sensor, the crank position sensor, the ignitor (and multimeter tested the ignitor since test lights won't work on two of the four wires even if functioning), fuses and relays.

 

I didn't check compression or fuel pressure. Here is what I did.

 

Pulled the air intake manifold.

Disconnected any connectors. I did not find any melted or frayed wires on anything anywhere under the intake manifold.

Reconnected everything and re-installed the air intake manifold.

 

Check the Main Wiring Harness coming from the O2 Sensor

I followed the positive wire from the oxygen sensor. It eventually tied into two other paths. One lead to a connector that led towards the transmission. (Didn't check it further.) The other led towards a main connector that connects to many things under the air intake manifold. In particular this positive wire leads to (I think it is called) the purge control solinoid valve.

 

All wires are intact. No fraying. No melted wire. No shorts. I reconnected everything.

 

I checked the O2 sensor for the 20th time. I got curious and switched the two white wires at the front O2 sensor where it is housed in the plastic connector.

 

I tried to start the car: IT WORKED!

I let it run for awhile and warm up. I threw the code: P0135 It ran for the next 35 minutes without dying. Previously, once warmed up it would stall and day. Eventually, it stopped working entirely and stopped giving any spark. I cleared the code, restarted it again, and waited. No code was thrown again.

 

Thinking that it could be due to the switched wires, I tried switching them back to before. It still started up fine. I switched them once again for superstitious reasons. It still starts up.

 

Preliminary Conclusion

Either some connector was not connected well or not at all. By taking everything off and on again, I seated a connector that was not previously seated properly, or I cleaned the contacts just enough by removal and re-instillation.

 

Sadly, I have not pinpointed what the issue was that causes the no spark issue.

 

I NEED to test drive my car and will as soon as I can get it out of the garage. (I'm blocked in.)

 

I will update as soon as I confirm it is working properly.

[uncutchemist]

I'm going to call this one a closed case. I put over 50 miles on it today, and it is running fine.

I am getting the front oxygen sensor code. I will replace that ASAP.

 

Thanks to everyone who provided insight. You are appreciated for every amount of effort.

[Dj7291993]

Maybe it was a loose ground.  Oh well, glad to hear it's working for you now.