Legacy won't start! Car is stranded in town!

[ACVWguy]

I got off work last night and went out to my car to start it and it wouldn't. It would crank and crank all day, but it wouldn't catch and start up. I have actually intermittently had trouble lately with it taking longer than normal to start. After about 10 seconds of cranking, it would stumble to life and then idle, rev, and drive like it was completely normal. Most of the time, it would start right up, though. Anyways, I have checked just about everything that could possibly keep it from starting: spark, compression, and fuel. And it all checks out.

Spark:
I pulled a spark plug and attached the cable to it and turned it over and it produced a nice glowing spark. To be completely sure, I hooked up a timing light to each of the 4 spark plug cables, one by one, then tried to crank it and the timing light flashed on every single cable. So it looks like I can rule out spark. Or can I?

Fuel:
I pulled the fuel line off the "out" side of the fuel filter and wrapped a plastic bag around it, hopped in the car and cranked it. Then looked inside the plastic bag and there was plenty of fuel in there. I also pulled a spark plug, and it was wet with fuel (smelled like gas). To be completely sure, I unhooked the intake tube from the throttle body and opened up the throttle plate, while spraying starting fluid into the manifold. I then quickly hooked up the intake tube and clamped it down, hopped in the car and tried to start it, but no dice. Again, it would crank and crank, but would not catch and turn on.

Compression:
The timing belt has 60k on it, so I thought it may be possible that the previous owner went cheap and didn't change the timing belt idlers and tensioner, so maybe one had seized and caused the timing belt to jump. It's a far stretch because the car ran perfectly all the way to work, but wouldn't start when I had to leave for the night. I pulled all of the belts, radiator fan, idlers, harmonic balancer off the front of the engine and removed the timing cover. I rotated the engine until i could line up the cam gears with the alignment marks on the heads and they checked out. The timing mark on the crank also lined up (the one on the back of the gear, not the arrow on the front). So the timing belt is fine. Nothing wrong with it.

It is beyond me what could possibly be keeping the car from starting. I decided to connect the black connectors under the dash to see if I had any stored codes (I cleared the codes a couple months ago, so these should have surfaced recently). The codes that I got (with the ignition in the on position, not running): were 21, 32, 42, 51. So coolant sensor, oxygen sensor, idle switch, neutral switch.

My car is a 1991 Legacy L Wagon 5spd 4WD with 260k.


PLEASE HELP

[topsecret888]

Had some starting issues with mine, a 91 legacy awd wagon. Did the usuals, new battery, new starter, check the alternator. Turned out to be a bad ground cable running from the starter to the battery. Got a new cable. So far so good. Keep fingers crossed. Check your wiring. Old cars with bad electrical wiring.

[MConte05]

Possibly a bad crank position or cam position sensor. Do you know anyone with an older Subaru you could swap with? Or just check the wiring itself to make sure it hasn't come unplugged or something.

Directly above the crank pulley under the alternator is the crank position sensor. On the right hand cam behind the timing belt cover is the cam sensor, just follow the wires to the plug. Unplug and replug them to be sure, check the contacts.

The sensors usually don't go bad since they are just simple magnetic hall effect sensors, but the wiring might corrode, or there might be a short.

[wtdash]

Hi,
Welcome...if you've not been officially acknowledged.

I vote we 'sticky' your troubleshooting steps....many could benefit from following the above.

I came across this POST online that is very similar to yours...yes, it's '98 OB and OBD2, but they are very similar to the earlier models- many of the parts on the engine are the same. It states the fuel pump relay switch could be the cause. Not something I've read about b4 so not sure where it is.

I'm not the mechanic on here, but the code CTS/21 might be the 1st place to look. They're a PITA to change, but not expensive, IIRC.

I'd also check grounds as suggested and I'd unplug the MAF sensor and see if it'll @ least start.

Hopefully the smart guys will lend a hand.

Td

[Legacy777]

Again,

Welcome to the BBS!

Yes, those are very thorough troubleshooting steps, nice work!

What part of the country do you live in? Has the ambient temperature gotten colder in the past few weeks or so?

Based on your comments that the car was having issues starting and would eventually start after cranking for a while, I'm leaning towards the coolant temp sensor as well. It plays a HUGE role in determing the ECU's fuel trims, startup enrichments, etc. This one little sensor can cause you a lot of problems.

The sensor is less of a pain to change on the non-turbo cars compared to the turbo cars, but it can be kind of messy. You can drain the coolant a little bit or try and do a swap between the old and new plugs quickly to minimize coolant spilling out on the engine.

The sensor is about $20 from the online subaru dealers. You may also be able to find one at a local autoparts store.

[ACVWguy]

Thanks for the help, guys!

I actually have been having to do all of this work in my parking lot at work, using my mom's Outback to jump the battery whenever I crank all of the juice out of it. After all of this trouble shooting, I went to the Subaru dealership nearby and talked to the head mechanic and described my symptoms and all of my process of elimination. He told me that there are two coolant sensors; one with a fancy plastic connector, and one with a single spade connector. The one with the plastic connector tells the ecu how to adjust the fuel mixture, and the one with the single spade is just the dash gauge sender. Since the coolant sensor relies on heat to change the resistance to the ecu, the mechanic told me that when the sensor wears out, it usually goes full rich and prevents the car starting. He told me that if I unplugged the sensor, the ecu set the A/F mixture full lean. So I tried it, and it still wouldn't turn over. But, since I am completely at my wit's end here with no possible solutions I can think of, I guess it's time to go to Pull and Save to start pulling some sensors off those cars and swapping them into mine. Lucky for me, Pull and Save is littered with 1st Gen Legacies.

I'll report back with what I find.

Thanks,

Austin

[Legacy777]

I would almost argue that the Subaru tech's comments are reversed, and that when the sensor fails it goes lean vs. rich.....but I've seen coolant temp sensors test ok, but when replaced the car starts fine. So they are tempermental beasts.

The other thing you could try breifly is just connecting the spare sensor to the electrical harness to see if the car would then start. The temperature should be around ambient, so the car should at least start. That would at least give you an idea whether a different sensor would work.

I've learned to trust the ECU's codes. The fact the code is there and the symptoms you're having would suggest to me the temp sensor is the problem. If a different sensor doesn't fix the problem, I'd suggest also checking the wiring from the sensor plug to the ECU. You can find a link to the wiring diagrams in the stuff you need to know forum.

[JDMSLIK]

Ya x2 on coolant temp sensor. Next one I'd try would be the maf. Don't know if this suggestion would be relevant but it sounds similar to an issue I had a few months back. When I was doing my rob tune ej20g swap I had two bad mafs in a row. First one was making the injectors run pig rich. To the point where it hydrolocked. Got a post on it here

http://forums.nasioc.com/forums/showthr ... ?t=2351375

Worth a shot

[ACVWguy]

Ok guys, sorry for the delay.

I had to leave the car overnight and when I got to work the next day, someone had broken into my car. Just broke my passenger side window and stole my walkman. The jackass left all of my tools including my volt/ohm meter, along with my zune and all of the quarters in my ash tray. Pissed me off, so I decided to spend all day getting the car running and fixed. I went to the local pull-and-save (which has 14 legacies on the yard) and dissected the passenger door to see how the window mechanism worked, pulled the glass (in excellent shape) and proceeded to vacuum all of the glass that got EVERYWHERE. I pulled a bunch of little bits of of the cars that were in good shape to replace mine. I got a new passenger tail light, new rear wiper motor (mine just went out), new driver interior lock switch (mine won't lock from inside), new weatherstrip that got ripped off when freezing rain glued my doors shut. Anyways, that's beside the point.

I pulled a crank sensor, cam sensor, and both coolant sensors from a car with <200k miles. I took the coolant sensor for the ecu and put it under the heater of my dads car and drove to where my car was parked. I then unplugged the sensor in the coolant rail and plugged it into the warm used sensor in my hand. I then grounded it against the block and got in the car. Whaddya know, she started right up. So I drove home with just the timing belt, no accessories belts and didn't use any electronics in the car so I could get home.

I put the used sensors in the engine and now the car runs and starts much better, but I feel like it could still start like new with some new sensors, so I ordered genuine Subaru coolant sensors on ebay and they should be here tomorrow. I also noticed that, though it hadn't slipped, the timing belt was showing some cracks around the outside, so I figured that since it had 70k on the belt, and who knows if the idlers were replaced, it was time to do a new timing belt and idlers. And since I'm in there, I'm getting all new radiator hoses, accessory belts, accessory belt tensioner, timing belt tensioner, cam/crank seals, thermostat, and water pump. They should all be here by the end of the week so I can get this car running like new!

MORAL OF THE STORY: The coolant temp sensor has so much influence on how your ecu manages the engine, that it can actually cause a no start situation. It can cause the mixture to be over-rich (in my case) and make the car impossible to start, even with fuel, spark, and compression. SO REPLACE YOUR COOLANT SENSOR. It's cheap insurance.

[JDMSLIK]

Timing belts with cracks are like time bombs.....that's a huge priority for you right now

[Someperson]

where are you located? I need a driver's door and some weather strip... also if you can find dark gray/black interior.....