Electric Assist Project: E-charger (2000 Subaru Outback)

[Dr. Jerryrigger]

Originally Posted by Clev

Looks like an Evap purge valve issue. You knock any vacuum hoses or connectors off your charcoal canister while working on this?

If that not it, try a little carb cleaner to free up the valve.

[brucey]

That's what I did, just cleaned it. Easy little sucker to get at. Seems to be working fine. I put the car in diagnostic mode and felt it clicking away. It might also be a bad 02 sensor (150K and original) or my catalytic converter (Always had the P0420 code) but neither of those are a biggy since my state doesn't require emissions.

[ShadeTreeMech]

Originally Posted by brucey

It might also be a bad 02 sensor (150K and original) or my catalytic converter (Always had the P0420 code) but neither of those are a biggy since my state doesn't require emissions.

A bad O2 sensor can ruin your fuel economy by making the ECU act as though you are running too lean hence causing it to richen the mix. And a bad cat can increase backpressure and cause the engine to work too hard to breathe. I wouldn't dismiss either one.

[Dr. Jerryrigger]

Originally Posted by brucey

That's what I did, just cleaned it. Easy little sucker to get at. Seems to be working fine. I put the car in diagnostic mode and felt it clicking away. It might also be a bad 02 sensor (150K and original) or my catalytic converter (Always had the P0420 code) but neither of those are a biggy since my state doesn't require emissions.

I envy your state. I've been trying to fix a p0420 this week, as I need to fix that big "R" sticker on my windshield by the end of the month. Autozone soled me the wrong o2 sensor this morning, and the old one might as well be welded to the exhaust.

Originally Posted by ShadeTreeMech

A bad O2 sensor can ruin your fuel economy by making the ECU act as though you are running too lean hence causing it to richen the mix. And a bad cat can increase backpressure and cause the engine to work too hard to breathe. I wouldn't dismiss either one.

But a bad O2 sensor could cause it to run lean, and a bad cat can have a big hole in it, which reduces back pressure. In fact if your state has no emission tests; you could improve your FE with a broom handle...

[Phantom]

A bad O2 sensor is most likely to read lean since the resistance will change causing the mV to read lower thinking that it needs more fuel. I do not see how it could become less resistive with age.

[dennyt]

Awesome project. I've been daydreaming about something similar: pulling the driveshaft, and installing an electric motor at the rear diff. There's no center diff in my Loyale, it's either FWD or locked 4WD, so this could work. Maybe next winter...

Kudos on biting off such a big project! Keep going!

Also, somebody mentioned "a switch could be wired to activate the motor when the throttle is at 0" to capitalize on fuel cutoff. I haven't read the entire thread, but make sure this is not an automatic function. The last thing you want when you let off the gas is TORQUE from that motor.

I'd recommend a hand-throttle, or perhaps a sideways gas pedal for the electric system? I saw a video once of a guy who made a "foolproof" pedal system, where there was only one pedal. Pushing down actuated the brakes, and moving your foot to the right pushed against the 'gas' pedal. That way, there's no way to accidentally hit the gas instead of the brake. You could build a gas/electric double pedal like this, to mix your power.

Have fun!

[ShadeTreeMech]

Originally Posted by Phantom

A bad O2 sensor is most likely to read lean since the resistance will change causing the mV to read lower thinking that it needs more fuel. I do not see how it could become less resistive with age.

From the wikipedia article
Normally, the lifetime of an unheated sensor is about 30,000 to 50,000 miles (50,000 to 80,000 km). Heated sensor lifetime is typically 100,000 miles (160,000 km). Failure of an unheated sensor is usually caused by the buildup of soot on the ceramic element, which lengthens its response time and may cause total loss of ability to sense oxygen. For heated sensors, normal deposits are burned off during operation and failure occurs due to catalyst depletion. The probe then tends to report lean mixture, the ECU enriches the mixture, the exhaust gets rich with carbon monoxide and hydrocarbons, and the fuel economy worsens.

Originally Posted by dennyt

I'd recommend a hand-throttle, or perhaps a sideways gas pedal for the electric system?

Originally Posted by brucey

That's the plan! Except it's going to be much simpler than that:

I'm simply going to have 2 independent throttles. I'll control the electric motor with my hand and the regular gas engine with my foot.

Just my 2 cents worth

[brucey]

When my FE goes down I'll fix it better. For right now, see my fuel log for non hypermiling driving. I think its running fine.

[brucey]

Small update: I have been running the belt without issue for about 20 miles now. Slight noise, might need to tighten (or loosen) it some to get it to go away. But the charger is spinning fine.

I was originally planning to do this for recent trip to florida, but decided I didn't want to risk losing a belt on the highway, even though it would have been a good test of 1000 miles each way.

I plan to look into the wiring some more this week, honestly I'm still clueless after scratching my head with the wiring diagram. It's like they intentionally left off half of it.

[Dr. Jerryrigger]

Originally Posted by brucey

Small update: I have been running the belt without issue for about 20 miles now. Slight noise, might need to tighten (or loosen) it some to get it to go away. But the charger is spinning fine.

I was originally planning to do this for recent trip to florida, but decided I didn't want to risk losing a belt on the highway, even though it would have been a good test of 1000 miles each way.

I plan to look into the wiring some more this week, honestly I'm still clueless after scratching my head with the wiring diagram. It's like they intentionally left off half of it.

Nice!
Loosing a belt on the highway wouldn't be that bad; as long as you have a replacement belt and tools. You would just need to pull over before your battery was to dead to start it back up.

I wouldn't think that the wire would be all that complicated; though simple things can be made very complicated with bad instructions. I'm sure you could get a little help from some of the EV people on this site.