Engine just won’t quit… Literally!

[Joe 90]

My engine just won’t quit… Literally!

Here’s the problem… Let’s see if anybody can help me solve this one.

Even when I remove the key from the ignition, the engine keeps running. All the accessories shut down like they should but not the engine!

I disconnected the connector from the ignition switch harness thinking that the fault could have been in the switch but the engine kept running. The only way I could “kill” the engine was by unplugging the MAS sensor!!

Is there a relay somewhere …..

Help me!!!

Joe 90

[Aredubjay]

http://www.subaru-svx.net/forum/atta...&postid=122599


Check this out. I should've given you a link to the thread, also. I'll post it in another reply.

[Aredubjay]

Here's the thread.

http://www.subaru-svx.net/forum/show...=Starter+Relay

[Joe 90]

Thanks aredubjay but the starter is fine, I’ll explain from the problem from the beginning.

I didn’t use the car for two weeks, when I tried to start it this morning, to my surprise, the battery was completely dead (I mean completely dead…) not a single light in the dash turned on.

After boosting it, it started just fine…. I let it run for a while and then when I turn the key to the off position, everything shut down except the engine! I disconnected the key switch harnes…. Bla bla bla….

I then killed the engine by disconnecting the MAS connector.

I guess some relay is stuck or something...

Joe 90

[lee]

interesting problem. I have a guess, but that's all it is.

My guess would be an internal short in the ignition switch. On the two switches I've taken apart (one US, and one English) there is basically a "hot" contact plate that is separated from the desired circuit connection by an insulator. When the key is rotated, the desired circuit is completed by appropriately placed "holes" in the insulating material.

Another way to look at it is like this:
At the "off" position, no contact is made. Only circuits directly connected to the battery operate, i.e., door lights, etc.
Turn the key to accessories, and certain contact points are exposed - radio may be on, clock is lit, etc.
Turn it to "start" and another set of contacts are made - cranks the starter, cuts out the accessories.
Finally, at the normal "run" position there is a set of connections made to keep the engine running and operate the accessories, but the starter is out of the circuit.

So my guess is one of two things:

A) the switch has an internal insulation breakdown so the "run" contacts are always connected. On both the switches I've had apart, the insulation was a plastic sheet made of whatever that stuff is that they use to make circuit boards. It was held in place by little metal tabs sticking out of the switch and matching notches in the insulator.

or

B) The switch has internally broken so the key mechanism is no longer attached to the electrical switch. This would mean the switch just happened to break at the "run" position.

With time and a volt-ohmmeter you could probably trace it out. Either (if my guess is right) would require a new switch, or for the brave, surgery on the existing switch.

Is your engine dieseling for some reason? I've heard this term used in relationship to an engine continuing to run even though the key has been removed. I'm sorta sketchy on exactly what causes it, but apparently it is related to improper combustion in the engine which causes "hot spots." I guess these hot spots can make the engine continue to run...

That's all I gotta offer... Sorry. Perhaps contact your mechanic and ask what could cause your engine to randomly start dieseling.

[svx_commuter]

Originally posted by deruvian
Is your engine dieseling for some reason? .................

I think it would be really noisy if this happened, alot of knocking and banging and missing. I remember that it runs rough and noisy and the exhaust smells.

Nevermind then!

[Joe 90]

The switch is not at cause since I disconnected it.... The engine is not "dieseling" since I can still rev-it up normally....

I just can't turn it off!

Tuff one insin't it?

There must be a relay sticking somewhere...

PS no factory anti-theft installed.

[lee]

Originally posted by Joe 90
The switch is not at cause since I disconnected it.... The engine is not "dieseling" since I can still rev-it up normally....

I just can't turn it off!

Tuff one insin't it?

There must be a relay sticking somewhere...

PS no factory anti-theft installed.

I can't seem to read - your first post mentioned disconnecting the switch, it just didn't sink in - thick skull on my part.

Wow! this is weird. I didn't think it could be done.

Anyway, there is an main relay with like a 6 pin connector. Can't say I've seen it, but I believe it's up under the dash, maybe by the ECU. really hard to tell from the diagram I was looking at.

[Joe 90]

Yeh, I saw it too.... "main relay", now, where is it located?

Could it be it?

[UberRoo]

Fuel injected engines will not diesel - only carbureted engines. Once the injectors shut off, the engine quits. The only exception is if your engine burns a LOT of oil, then it will actually run off the engine oil itself. (Yes, I've seen it happen. You will definitely know if you're burning that much oil.) (For those who are curious, sometimes dieseling can rattle and knock something horrible, or it can be quite smooth and sometimes you can drive around that way.)

Also, the starter relay has nothing to do with this. If you can start the car, and it doesn't make the world's most horrible grinding and screeching noise when it's running, the starter relay and starter are working just fine.

1.) Are you certain you disconnected the ignition switch? Normally they make that pretty hard to do, thus making the car difficult to hotwire for theft prevention. (I'm not convinced that you have completely or successfully disconnected the switch. You might try some serious jiggling and tapping on the switch to see if it jars something loose.)

2.) Do you have remote start OR an aftermarket alarm? (Not just anti-theft.)

3.) Does anything else in the car continue working when you turn the key from the run position to the stop position? (Headlights maybe? They don't operate quite the same as the accessories.)

4.) Will it allow you to put it in gear (with the key removed?)

Honestly, if you did completely disconnect the ignition and there is NO aftermarket wiring in the car, I'm not sure where to start looking other than at the various relays. With the key removed, you might just start pulling fuses one at a time and see which ones make the engine quit. (There may be several which do.) Trace those fuses to the nearest relay. I wouldn't think any harm will come to your engine while doing this, but you might put the key in frequently and check to make sure everything is running correctly, like the radiator fan cycling properly. Make sure you pull both the fuses under the dash, and also the ones under the hood. Pull the small relays too.

[Joe 90]

I installed a remote starter on that car several years ago. That module was my first suspect on the list. So while the engine was still running (with the key in my hand), I disconnected all the connectors from this module.... Nothing happened, the engine kept running. Then, I went on to disconnect the key switch harness after removing the cover under the steering column.... Again, nothing happened, the engine still kept running....

So, it doesn't look like the remote starter module or the ignition switch is at fault. There must be a relay or something that sends current to the ECU and fuel injectors even when the key is off!

[svx_commuter]

This is a Joke? Right?

I also have a SVX that keeps running, it turns off, when i use my key, but i can remove my key, I find it kinda nice lately, I just lock her up, and let it sit in the parking lot idling while i go in places...HEHE..