Popping the clutch with dead battery

The other night we listened to the radio in the wife's scion until the battery died. The dash lights would come on, but the brake lights would cause them to dim and the headlights were very dim. Turning the key just made the click-click-click noise.

So, I drifted it down the driveway, popped the clutch in second. It turned over but didn't start. So, I drifted out onto the road. There is about a 1/2 mile slope down. The whole way the engine was spinning about 1000-1500 rpms and the lights were getting brighter, but still no catch.

Wife came down with jumper cables and it fired up instantly.

This phenomenon happened to me one other time in an 88 Maxima. I could understand how some ignition systems need more juice to fire the coils, but a 1/2 mile at 1500 rpms wouldn't do it? The lights were getting brighter, and at the bottom of the hill it actually tried to crank, so it was making juice.

Why? Why??? WHY???

But seriously... why wouldn't it start?

not enough juice to run the fuel pump...

Too many electrical draws needed to make the Scion run. Electric fuel pump, ECU, etc. Rolling down the hill in gear didn't get the alternator spinning to the point where all the supporting systems had enough juice to work.

"we listened to the radio in the wife's scion until the battery died." ...you don't say.

Every time I hear about stuff like this, my conviction to keep life simple increases:

Lights were getting brighter? You don't mean the headlights, do you?

Most computer systems don't work below 9v.

Also, some cars won't allow the engine to start if it doesn't see the key turned to the Start position.

Any relation to the switch at the clutch pedal that does not allow the car to start w/o pedal depressed?

Sounds like electronic ignition. I had an issue on a little dirtbike that ran out of charge, the bike had fuel and compression but honda used a damn electronic ignition so it didn't matter the bike wouldn't run. Give me a magneto.

Takes over 150 watts just to run the thing. Headlights are an additional draw. big draw.

Not enough power to boot the computer, and run the pump, and drive the ignition. Old cars with generators that made power at any RPM and had mechanical fuel pumps would push start with a completely dead battery. Once you get new enough to have computer controlled ignition and fuel injection push starting will only reliably solve starter issues.

The Yugo with its dumb electronic ignition will stay running until you can't see 3 feet in front of the car. Then sputter and shoot fire out the tailpipe like a shotgun going off and light up the neighbors house like the sun, and then run fine for another minute, probably under 6 volts by that point.

JohnRW1621 wrote: Any relation to the switch at the clutch pedal that does not allow the car to start w/o pedal depressed?

I think that is to engage the starter, not the ignition.

Steady voltage. Some computers do not like electrical ripple and tend to not work if there is to much in the system.

http://en.wikipedia.org/wiki/Ripple_%28electrical%29

Paul

benzbaronDaryn wrote: Sounds like electronic ignition. I had an issue on a little dirtbike that ran out of charge, the bike had fuel and compression but honda used a damn electronic ignition so it didn't matter the bike wouldn't run. Give me a magneto.

Preach!

That is one thing I really like about my old Honda, magneto fired ignition. Fortunately when the Chinese copied the Honda engines (under license BTW), they went with a magneto ignition. You can take the battery out and you can still start the bike.

Kenny_McCormic wrote: Not enough power to boot the computer, and run the pump, and drive the ignition. Old cars with generators that made power at any RPM and had mechanical fuel pumps would push start with a completely dead battery. Once you get new enough to have computer controlled ignition and fuel injection push starting will only reliably solve starter issues. The Yugo with its dumb EFI will stay running until you can't see 3 feet in front of the car. Then sputter and shoot fire out the tailpipe like a shotgun going off and light up the neighbors house like the sun, and then run fine for another minute, probably under 6 volts by that point.

FWIW I've roll started several Honda's with batteries that wouldn't even click ...

on an aside I once roll started a '62 Jag Sedan with an AT ... 35 mph, key on, pulled gear lever from N to D .... and away we went

In reply to wbjones:

Rear pump will let you do that.

Warren v wrote: Lights were getting brighter? You don't mean the headlights, do you?

No... dashlights

I've had countless EFI cars that would start instantly when you popped the clutch. I'm sure its just some different parameter or threshhold that makes some cars do it and some not. I even tried cycling the key a few times because the fuel pump only runs for 15 seconds to prime the rail. It should have sensed the CPS and tried to run.

In reply to curtis73:

Yeah, some of them think they're being stolen when you do that. Cavliers/Sunfires will rarely push start, I actually managed to stall mine pulling away from a light once, and it then decided it was being stolen and I had to cycle the key a few times to get it going again.

Kenny_McCormic wrote: The Yugo with its dumb electronic ignition will stay running until you can't see 3 feet in front of the car. Then sputter and shoot fire out the tailpipe like a shotgun going off and light up the neighbors house like the sun, and then run fine for another minute, probably under 6 volts by that point.

I had a belt-loss incident with my first RX-7. Alternator belt broke, making one hell of a noise when it hit the hood.

I was about 40 minutes from home and it was getting dark, so I just went for it. About 15 minutes from home, the lights were so dim that I just said screw it, the headlights aren't doing anything anyway, so I turned 'em off. Voltage was so low that the headlight motors could not pull the headlights down against wind resistance.

This was clearly an unsafe way to drive, so in the interests of minimizing the time exposed to danger, I went as fast as the car could go. This turned out to be only 90mph or so because the fuel pump and/or MSD weren't getting enough juice. I couldn't really read the gauges at that point.

Car ended up dying one exit before home, so I deadsticked it in to the nearest gas station and phoned a friend to give me a jump-start.

Yeah when the alternator finally crapped in the X3 I had the same issue. Just wouldn't bump off. Quick charged the battery and varoom! fired right up.

Just not enough being put out to runt the FI system.

That battery's probably going to give you a lot of trouble now. Once you've run them that low, they lose charge much faster when just sitting. It'll probably be useless within a few months.

In reply to GameboyRMH:

Depends how good of a battery it is, I had a 4 year old Delco that I accidentally ran down till it froze twice, and sold in the car as a 6 year old Delco that still worked fine even if I let it sit a few weeks.

You should expect it to die soon, and keep an eye on it, because a bad battery will kill a alternator just as good as things work the other way around. Though sometimes you get a battery that just wont die.

Yeah, yeah. But all we're talking about here is four amps.

In one of the mercs I had with an auto trans it had instructions in the owners manual on how to roll start it.