CRXFi Build Thread (Geo Metro XFi drivetrain in Honda CRX)

[MetroMPG]

Probably a good idea to stick with the Metro relays - didn't the Hondas have a common problem with faulty fuel pump relays malfunctioning when hot?

I ride past a place with 2 CRXen in the driveway pretty regularly (twice today). Always makes me wonder how this project is coming along.

[Christ]

Originally Posted by MetroMPG

Probably a good idea to stick with the Metro relays - didn't the Hondas have a common problem with faulty fuel pump relays malfunctioning when hot?

I ride past a place with 2 CRXen in the driveway pretty regularly (twice today). Always makes me wonder how this project is coming along.

It's dry solder joints that caused the problem, and it's about a 10 minute fix (once you figure out how much of a buzzard it is to get the main relay out of it's location, and never intend to put it back there again.)

[Wonderboy]

Yay! Today after learning how a started solenoid works (thanks to Christ), I got the car cranking. Both the fuel pump relay and the injection relay work. I'll fool around with it a bit more because I decided to quit while I was ahead. What happens now is when I crank it and release the key into position 2, it shuts right down. If I keep it cranking, it responds to opening the throttle. I didn't finish checking for damn sure that I took all the wires I needed from the CRX harness to the metro harness, so I'll make sure that's right then see what happens, but assuming the same thing happens once I'm done, what should I look at? Maybe the fuel pump since I'm using the CRX pump? It is most definitely delivering fuel or else it wouldn't respond to throttle, but what do I know about these things? After all, I just learned today that a starter solenoid not only turns the engine over, but actuates the starter gear onto the crown wheel; Then, once you release the starting position of the key, the little gear in the starter gets pulled back from contact with crown wheel gear. I'm worried that I'm going to hurt the engine since it's newly rebuilt. I don't know if it's bad to keep cranking it over if it's not going to want to idle for the 30 minute break-in. Any insight on this from the wise? Hopefully this will all get sorted out once I correct all of the wiring. I'm excited anyway that I got it cranking from the inside of the car at least.

Oh yeah, my battery died down to about 3.6v since the last time I worked on it because my climate control panel light stays on constantly regardless of key in or out. That'll drain the battery eventually.... gonna have to figure that out too.

[Christ]

Originally Posted by Wonderboy

PROGRESS!!!!1!!!11

Werd!

So, the key thing is simple - there is a circuit somewhere that isn't connected. When you crank the engine, it gives power to both the starter solenoid AND the ignition circuit, etc... When you let go of the key and turn it to run, there's no power (in your case, normally there is) going to the ignition/fuel pump or some other thing.

First thing - test at each component with the key in the "run" position. Check at the main relay, the ECM, the fuel pump, and the ignition coil. You'll feel really dumb if you go through all the work to trace wiring and find out that it's something really simple (Been there, done that... got the T-shirt, somewhere.)

If you're not getting power to any of those things with the key in "run", chances are, you're either missing a wire, or you have a fault in the wire.

Your heater control panel is probably constantly on because you have a wire switched somewhere. If you can post any details about how you did the wiring (which wire color/pin/location from each harness you connected) we may be able to help out better with that/those situations.

In any event, no, you should not keep starting the engine if you can't keep it idling for any length of time (Idling with the starter still engaged will destroy the starter.) (BT, DT, GTTS - again)

Sounds like you're that much closer! I have to say I'm very impressed with your abilities and progress on this project, especially since you're not from a mechanical background. This is the kind of thing that many of my friends can't do, and most of my friends are just like me, except focusing on specific manufacturers and design features.

[RobertSmalls]

Running a starter with a battery that's low on charge will shorten the life of the starter dramatically, and deep-cycling a regular battery will kill the battery. I'd keep it on a battery charger and leave the battery cable off until you can fix the electrical drain issue.

Once you've got it running and the wiring done, I'd take a measurement of standby current. A car like yours with no gizmos should draw <100mA with the key out and doors closed.

[Wonderboy]

I don't remember if the fuel pump relay and the ignition relay are on in key position 2, but I just had an epiphany: the wire that goes from the relay to the key switch is actually 2 wires. One is probably for the starting signal and one is probably for position 2? I otherwise can't figure out why two wires would've been joined into one pin for the CRX main relay. This was the case for 3 different pins on the CRX relay, I believe. One of those pins I didn't end up having to use.... or did I?

Your heater control panel is probably constantly on because you have a wire switched somewhere. If you can post any details about how you did the wiring (which wire color/pin/location from each harness you connected) we may be able to help out better with that/those situations.

I bet you a dollar it's happening because I took the climate control from a civic hatch, not a CRX. The pins back there are probably different since CRX has blower controls as electronic, not a cable driven thing (I touched on this earlier in the thread). CRX climate controls are sh!t-spensive, so I'll just figure out how to retrofit the Civic one later (good thing I have that 88 HF service manual!) and just unplug it or the battery for now. Battery chargers are sh!t-spensive too for how much I'd use it. Time to go commandeer one from the 'rents!

[MetroMPG]

I think we need to add a giant "Thanks" button to this thread just for Topher's input. Eh? Something big enough that you need both hands on the mouse to click it.

Go Will! Can't wait to read "it lives!"

[Christ]

Originally Posted by Wonderboy

I bet you a dollar it's happening because I took the climate control from a civic hatch, not a CRX. The pins back there are probably different since CRX has blower controls as electronic, not a cable driven thing (I touched on this earlier in the thread). CRX climate controls are sh!t-spensive, so I'll just figure out how to retrofit the Civic one later (good thing I have that 88 HF service manual!) and just unplug it or the battery for now. Battery chargers are sh!t-spensive too for how much I'd use it. Time to go commandeer one from the 'rents!

This is quite possible. I've interchanged them before, but there I've always interchanged the whole system, and always from a CRX into a Civic, never the other way around... I'm not entirely sure if I ever had to change any wires around (other than installing a complete harness to control all the selector motors), so I'm not going to be too much help there.

As far as the 2 wires into a single pin thing, you'll find that on a couple occasions in the CRX/Honda in general harnesses... It's best to leave them that way, if you can, because they usually go to different places.

For instance, on the DPFI injector wiring, there are two grounds, one for each injector. ON the MPFI wiring, there is only one ground, but both wires still exist... they're tapped together in the wiring.

Darin -

Thanks for that.

[Wonderboy]

Go Will! Can't wait to read "it lives!"

IT LIVES! Hahah How did you know I was working on it tonight? Seriously though, I haven't touched the car for a solid week of other stuff I had to do and night meetings, then tonight I decided to go out and battle the relays. It wasn't turning on the relays when I turned the key to ON, only when I cranked the starter. With some wire tracing and re-verification, I did some trial and error with those double-wired pins I got from the CRX's main relay. It turns out it only needed one wire out of the two pair to do what it's supposed to. Now, I turn the key on, the injector relay stays on (I think), and the fuel pump relay turns on for 2-3 seconds, then turns off. It starts up with hardly even a hiccup, then idles (a bit quickly). I can't tell exactly how quickly, but it just sounds fast for an idle, even a warmup idle. The idle then slowly begins increasing in speed, and I get nervous because I don't want to injure it, having been freshly rebuilt and all. Anyone know what I should do to troubleshoot this? I ought to figure out how to rig up the tachometer because it didn't come with one, and the harness doesn't accommodate one AFAIK. Then I'll at least be on the way to knowing the RPM (with some 4cyl to 3cyl math for the time being).

Oh yeah, there's a little exhaust leak up front somewhere too

I think we need to add a giant "Thanks" button to this thread just for Topher's input. Eh? Something big enough that you need both hands on the mouse to click it.

Amen to that. Until you figure out a superthanks button or I figure out a better way to pay him for his services, Topher will have to make do with the applesauce, maple syrup, car hauling, and the convivial friendship I give him. He's spoiled anyhow.

[Christ]

Originally Posted by Wonderboy

IT LIVES! (other words Will said)

Don't you have a bicycle computer laying around? You could put the magnet on a rotating part of the engine and do the math to count back to RPMs that way... Lots of work, but it should work, ideally.

On the other hand, it's probably just as easy to get a general idea of engine speed by hooking up the CRX's green wire (at the dizzy) to the ignition (-) on the coil of the Metro engine. (I'm relatively sure that will work, anyway.)

Usually, aftermarket tachometers are driven by the negative side of the coil. They get a signal based on the number of times the coil is switched per interval of time. I think the CRX's tach works the same, but can't be sure about it. It's connected to the ignitor module, which works similarly to contact points in the points and condenser ignition system, only instead of being operated by an eccentric lobe, it's operated by the ECM/ECU/PCM/Whatever you want to call it.

My other stupid idea at one point was just to drill/tap a hole into the approximate center of the crank pulley bolt, and attach a tach from a motorcycle which was driven by a cable. Not sure how that would have worked out, though, since I never actually did it.