My Subaru wont start. Nico, come to my rescue.

[IanS]

Now I know, I know, this is Nico, not Nasioc, but I also know there are a handful of Suby owners on here, and I trust you guys. Plus there is more traffic here.

Special Nico exclusive. If you can figure this out for me, I will give you some free space on the rally car. Send me a sticker, tell me to paint something, write your name. Whatever makes you giggle, as long as its not vulgar.

It wont start, it cranks perfectly, but it has no spark, and no injector pulse.

Here is the back story.

I purchased this car a few weeks ago, in non running condition. It is a 2002 Subaru Impreza WRX sedan 5MT. The hack previous owner had molested it hard. With less than 50K on the clock, he blew the motor. Im not sure how, or what failed, all I know is that he had a remanned short block installed by some shop. At around 55K, the motor popped again. Apparently at this point, he gave up, parked the car, and put it up for sale.

It sat for at least a year because he was asking way too much. Finally, I was able to talk him into letting it go for cheap.

When I got the car, it was obviously lacking compression. Instead of fiddling with it, I just pulled the motor and stripped it down. Piston No 4 was destroyed. Detonated all the way through the ring lands, and cylinder walls all scuffed up. As far as I can tell, the only performance mods, were a strut bar, a perrin turbo inlet, a home made warm air intake tube, and a ebay fart cannon. My guess is, the stupid intake (angled exhaust pipe welded together), along with a teenager with a heavy foot did the damage.

I decided to start fresh. I am returning the car to 100% factory stock. I picked up a motor from a salvaged 03 WRX with only 6000 miles, but busted cam gears. I pulled the heads, replaced all the gaskets with OE subaru stuff, and put it all back together. I installed new subaru T belt tensioner, water pump, toothed idler and thermostat. I used the cam/crank cogs off the old engine, along with the timing covers.

I dropped the new engine in, and tried to start it. Nothing, it just cranks. There is absolutely no spark, and no injector pulse whatsoever.

I swapped the cam and crank sensors over from the other engine.
I checked the cam and crank cogs for broken teeth.
I checked the signal of both sensors at the sensor while cranking.
I checked the signal of both sensors at the ECU while cranking.
I checked the resistance of the wiring between the cam/crank sensors, and the ECU.
The fuel pump is coming on.
There is fuel pressure.
I drained the tank before trying to start the car. It has 5 gallons of fresh fuel in it.
The fuel lines are installed correctly.
There are no blown fuses.
There are no codes in the ECU.
The ECU registers engine speed while cranking.
The tack does not show RPM during cranking
All injectors are getting power.
All the coil packs have power.
When I installed the timing belt, I triple checked the timing. I have done 5 DOHC subaru timing belts before.

Now the weird stuff.

The check engine light is sometimes on while cranking, always on while key is on.

Sometimes with the key on, the security light will flash 4 times, short pause, 1 time, then long pause, and repeat. I have tried unplugging the security box under the console. I have also tried cycling the key 3 times in the ignition.

I have also tried using the intake manifold wiring harness from the other engine.

Seriously WTF. I have never been stumped like this in my life.

I am this close to pushing it onto a trailer, and taking it to work so I can use the shops "big boy" scanner to check things out. My personal scanner only allows me to look at a small amount of live data, and check codes.

Please help me. I am beginning to think its the ECU, but I have no way to test it.

[Urabus GodofTraction]

Coils firing?

There are minor differences between 02 and 03 ECUs. What ECU and what harness are you using?

[Zydeco]

I'm not good at fixing big problems like this. Might want to give iwsti.com a try. I'm wouldn't touch NASIOC a try. too many Nazis over there.

[PoorManQ45]

Honestly, it sounds like you may have missed a ground point.

I didn't see it in there, but the ECU could be toast.

[Oatmealman]

You got me beat,my first guess before i finished reading was cam/crank position sensor.I'm almost with charlieo but the fact the injectors aren't firing as well makes no sense.

[PoorManQ45]

You have two common factors between spark and injector pulse.

They are:
ECU
Ground

[IanS]

Coils firing?

There are minor differences between 02 and 03 ECUs. What ECU and what harness are you using?

Coils have good power, but are not being triggered. So no, the coils are not firing.

I am using an 02 ECU. The only part of the 03 control system is the wire harness for the intake manifold. This does entail both the coils and injectors. I have tried using the IM harness off the other engine. No change to the coils or injectors.

Honestly, it sounds like you may have missed a ground point.

I didn't see it in there, but the ECU could be toast.

Grounds are good, checked and double checked. Subaru's are easy, there are only 2 major engine grounds, both are connected. As is the small one on the firewall. ECU is my favourite to be the culprit, but there is no good test that I have found, because it does have power, is coming on line. I can read live data, but it shows no codes.

You have two common factors between spark and injector pulse.

They are:
ECU
Ground

You are forgetting 1 thing. Security systems. The code 41 coming from the security light has me thrown for a loop. I can't find any info on it. Plus, Subaru uses constant power coils and injectors. The ECU sends a grounding signal. The coils are 3 wire with a dedicated ground added, and it is good. The injectors 2 wire with good power, but no signal coming from the ECU. I have only tested at the injector. Today I plan to check right at the ECU, to see if the signal is just getting lost in translation.

[PapaSmurf2k3]

You got me beat,my first guess before i finished reading was cam/crank position sensor.I'm almost with charlieo but the fact the injectors aren't firing as well makes no sense.

+1

Do you have another ECU you can try?

[IanS]

+1

Do you have another ECU you can try?

I wish I did. I know a bunch of local subie guys, but none of them are stock. They all have tuned ECUs, or are 04 and newer.

[PoorManQ45]

It could be something as simple as a relay not having its ground attached.

Sorry if I'm not much use, I'm an electronics guy.

[Chaotic_Warlord]

You should ask the previous owner if he had an aftermarket keyless ignition or alarm installed on the car. It sounds to me like you may have a kill switch wired into the ECU that is preventing the car from actually starting. I don't think trying a different ECU would do any good unless you stripped out the entire existing harness and installed a new harness. It sounds to me like you pulled out the engine and dropped in a new engine without touching the existing harness much (if at all).

It seriously sounds like there is something wired into the ECU that is not allowing it to send the proper signals to the injectors and spark plugs to allow it to start. Go over every inch of the car and look for a kill switch or a box that doesn't look like it belongs. I'm willing to bet that if you took the ECU you have out and tested in another car that it would work just fine and vice versus if you tried a different ECU in your car it still wouldn't work. if there was an issue with the ECU you would definately be throwing codes that even a cheap code reader would be able to catch.

[IanS]

You should ask the previous owner if he had an aftermarket keyless ignition or alarm installed on the car. It sounds to me like you may have a kill switch wired into the ECU that is preventing the car from actually starting. I don't think trying a different ECU would do any good unless you stripped out the entire existing harness and installed a new harness. It sounds to me like you pulled out the engine and dropped in a new engine without touching the existing harness much (if at all).

It seriously sounds like there is something wired into the ECU that is not allowing it to send the proper signals to the injectors and spark plugs to allow it to start. Go over every inch of the car and look for a kill switch or a box that doesn't look like it belongs. I'm willing to bet that if you took the ECU you have out and tested in another car that it would work just fine and vice versus if you tried a different ECU in your car it still wouldn't work. if there was an issue with the ECU you would definitely be throwing codes that even a cheap code reader would be able to catch.

The previous owner is not available. He wont answer his phone or email. He failed to mention a lot of the problems the car had, and all of his workmanship was poor. Im sure he is worried Im going to chew his a** out, which I would. Some people should not be allowed to work on cars.

Back to the problem. I have checked the wiring near the ECU, and up under the dash. None of it has been modified, and as far as I can tell, the ECU had never been removed before I pulled it.

I have checked under and around the steering column, and there are no signs of an aftermarket alarm install. I have installed alarms, and I know where connections need to be made. There is no evidence of any of that. Plus, aftermarket alarms almost always lock out the starter solenoid. Every WRX came from the factory with an OE alarm and keyless entry system. The PO failed to provide me with a remote, but the system can be disarmed by cycling the key in the ignition 3 times. Also, the factory alarm disables the starter. It may also disable spark and fuel, but I have found nothing indicating so.

The PO could have purchased a super high quality alarm, and had it professionally hidden, but judging by all the poor quality work, and ebay parts (the perrin inlet is the only name brand piece) he was a huge cheap a**.

There are no toggle switches save for the one wired to the stupid illuminated wind shield washer nozzles. He wrecked a perfectly good window switch plate to put it in.

Often times, if the hardware in the ECU fails, it will through all sorts of codes. But if there is a bug in the software, chances are good, no codes are thrown. The ECU thinks its doing its job. From what I know of Subaru ECUs the only way to simultaneously disable spark and injector pulse, would be to interrupt the crank signal. I have checked this wiring, and it seems to be fine, plus watching the ECUs live data, shows an engine speed signal during cranking.

[IanS]

Could be an issue relating to a engine immobilizer. Does your Impreza have that?

As part of the security system maybe. AFAIK Subaru did not start using immobilizer keys until 2006. Unless it was a dealer option. I guess its worth a shot though, I will look into it.

Thanks for the ideas guys.

[Urabus GodofTraction]

I'm officially for finding an ECU that matches the model year of your car. They should be cheap enough it's worth a shot for troubleshooting.

[Zydeco]

Could be an issue relating to a engine immobilizer. Does your Impreza have that?

Subaru didnt start immobilizer keys until 05 and then its was standard on the STI. You could still get it as a option on the WRX though.

[PEZi]

i also support ECU....

[PoorManQ45]

If it's ECU, I claim that space you offered!

The first two responses asked questions about the ECU, but didn't suggest it was the problem

[IanS]

Ok, I know its been a while since I updated this, but I am still fighting this.

It is NOT the ECU. I had an opertunity to plug my ECU into another 02 WRX, and it started right up, and ran perfectly. The problem lies elsewhere.

I have also gone through and rechecked the timing belt. Everything is in the correct position.

I keep coming back to the security light.

I have still not been able to find any evidence of this having ever happened before. I have been to 2 dealerships, and everyone I talk to is mystified. I have pulled half the dash apart looking for any modifications to the wiring. Everything seems to be as it should. There is nothing behind the cluster, under the steering column cowl, the center console, behind the stereo deck, and under either side of the dash.

I am officially stumped.

[Chaotic_Warlord]

I'm willing to bet it's something stupid like a short in the harness or a pin not fully punched down. Since you haven't found any evidence of a kill switch or anything that would be a sign of a security starter interrupt, then it has to be some sort of electrical short. Electrical gremlins are quite possibly the hardest and most frustrating problems to ever get sorted. You more than likely have a nicked wire that is touching something. Time to bang your head off a wall and literally go over every single inch of the harness. I do not envy you right now, but a I hope you get it sorted out, nothing worse than having a bricked car.

[IanS]

I'm willing to bet it's something stupid like a short in the harness or a pin not fully punched down. Since you haven't found any evidence of a kill switch or anything that would be a sign of a security starter interrupt, then it has to be some sort of electrical short. Electrical gremlins are quite possibly the hardest and most frustrating problems to ever get sorted. You more than likely have a nicked wire that is touching something. Time to bang your head off a wall and literally go over every single inch of the harness. I do not envy you right now, but a I hope you get it sorted out, nothing worse than having a bricked car.

Really though. I have dealt with wiring issues before. I have checked signals at the ECU, and as far as I can tell, it is getting what it needs to attempt a start, yet it will not. This leads me to believe that it is choosing not to fire the coils/injectors because another module is telling it not to. Which module, and why, is beyond me.

A single short will not cause a light on the dash to flash a code. Some part of the car knows something is wrong, but I have yet to be able to figure out what part, and how to talk to it. Really what I need, is more info about the security systems, but that is not something normally available to the public.

[PapaSmurf2k3]

Stand alone ECU?

[Kenne21]

Could be something with the immobilizer in the car's ignition if the car is equiped with that. If it's the origional key you could try putting the key in the ignition and turning it to on and leave it that way for 10 minutes or so. Then try to start the car. if the car does have the immobilizer it should let them resync to eachother.

[Kenne21]

Or try turning the key to just before it cranks over and there should be a reset/valet button/toggle switch on the alarm box...push it and hold it til the light goes solid and the car should chirp turn key off and then try to start it...if its a toggle do same but flip it then turn key off and then try to start.

[Chaotic_Warlord]

Why not give Subaru a call directly and ask them. Just because a Subaru tech is just as stumped as you doesn't mean that the issue hasn't come up before anywhere in the world. Their American HQ is in Cherry Hill NJ, I know exactly where it is as I've had to do service calls across the street several times.

[IanS]

Stand alone ECU?

Im not fixing this car to keep it. I bought it, am fixing it, and returning it to stock, then I am selling it.

Could be something with the immobilizer in the car's ignition if the car is equiped with that. If it's the origional key you could try putting the key in the ignition and turning it to on and leave it that way for 10 minutes or so. Then try to start the car. if the car does have the immobilizer it should let them resync to eachother.

Or try turning the key to just before it cranks over and there should be a reset/valet button/toggle switch on the alarm box...push it and hold it til the light goes solid and the car should chirp turn key off and then try to start it...if its a toggle do same but flip it then turn key off and then try to start.

Subaru did not start installing key based immobilizers until 2005, and it was only on the STI model until 2006.

I only have a single key for the car, and it is not an original. I have pulled the cowl off the column, as far as I can tell, there is no sensor ring on the ignition, just the trigger for the key beep.

There is no switch on the security module, just the potentiometer for the shock sensitivity. To reset subaru alarms, you toggle the key from lock to on 3 times in 5 seconds.

Im looking into aquiring a remote, but I doubt it will be of any help.

I have thought about it, though Im not sure calling the corporate headquarters would be all that helpful. Its likely just full of office workers.

[Kenne21]

My buddy alex finally got back with me and he is like a subbie guru he builds them and he said he thinks and would try this:

unplug the battery for an hour, its the lockout is activated. or take it to an open source tuner and have him reprogram it, in 02 they didnt have chips in the keys yet so he is fine there. but its either a bad lockout box, or a random occurrence with spark and fuel, if he has a stethoscope he can listen to each injector and see if there trying to open at all and the fuel system is just not primed.

[IanS]

My buddy alex finally got back with me and he is like a subbie guru he builds them and he said he thinks and would try this:

unplug the battery for an hour, its the lockout is activated. or take it to an open source tuner and have him reprogram it, in 02 they didnt have chips in the keys yet so he is fine there. but its either a bad lockout box, or a random occurrence with spark and fuel, if he has a stethoscope he can listen to each injector and see if there trying to open at all and the fuel system is just not primed.

Lockout box? Dont know anything about that. I have had the batter in and out many times. It sat for a few weeks without any battery at all. As for a retune, the ecu works fine in other cars.

Ive used noid lights, and a DVOM on the injectors. There is plenty of fuel pressure, but I have never gotten any signal to them from the ECU. Same for the coils. Its not that the wont/cant work, its that nothing is telling them to. In theory, the only thing I know of that could kill both, would be the crank sensor. As far as I can test, its working. The ECU sees signal, the wiring is good, and live data is showing RPMs while cranking.

[Kenne21]

still waiting to hear back from him...he takes forever ill let you know when he gets back with me on that

in the mean time...what about your cam sensor being bad? you said you checked grounds...did you just check there connections or did you trace the wires and make sure they were un harmed? might have nicked one and it broke just enough to not work now

[Kenne21]

also i had a similar problem on my last 240 turned out the engine didnt have a solid ground to the chassis...once i ran a new ground it started right up

[Kenne21]

Ok in response my buddy said:

lockout box is just the term i use, its just his security system. might be a dealership issue. ill ask around but i think theres something funky going on with his security.

engine managment is a f'd up thing to deal with