FastWoman

Grrrrrrr.... I think in its last hurrah, the failing alternator must have overvolted my system. My power amplifier and power antenna both seem to be kapoot -- pending further diagnosis, that is.

The transmission was stone cold and had been sitting for a couple of days. (I'm waiting for a new alternator.) Looking at a diagram of the transmission, the shifter assembly would/should be well above the oil level in the transmission. I had the oil changed relatively recently by a Z specialist. I presume he knows the correct fluid level for these things, and I would think it would be impossible to overfill. Dunno. I've read in the Miata forum that the "cup" should be filled with oil, but like you, I've never seen this before, and we're talking about a different car. It seemed strange that the oil slurped over. If anything, you'd expect the oil to drain away over time (into the transmission).

Hi all, I just finished replacing my shifter bushings with the brass eBay variety. Now it's very nice and tight. However, when I pulled the boot off of the shift linkage assembly, it was full of gear oil and in fact overflowed a bit onto the ground. Is this the way it's supposed to be?

Zed, I think the key fact in the diagnosis was that I was driving with an excited alternator that suddenly (without my having stopped the engine) lost output. So even if the plug had come loose, that wouldn't have accounted for the problem. I suspect you're right about old/used vs. rebuilt. However, I do know that part of the rebuild, at least on these alternators, is a complete replacement of the old voltage regulator and diode board with new -- probably made in China or Mexico. (That's probably where the problem is.) I wonder whether I'd fare better with an external voltage regulator style of alternator.

Cesar, the kink appears to be on the intake line. Right? I'd say that restriction is quite likely to be sucked shut. If it were on the pressure side, you might have a bit better chances.

I suspect there's some rotted weather stripping stuff on the various air handler doors that would otherwise seal them tight. Mine blows a bit of cool air out the dashboard vents too. Another project, someday!

To me, the BMW Z3 has much more Z'ness to it, with its lovely inline-6 engine. It would be more appealing to me if it weren't so heavily computerized. I love the simplicity of the Z and the intimacy it gives me with its drivetrain, and no modern car can give me that. My 1994 Miata is about the most modern car I could really love.

My L28 runs perfectly when stone cold in the dead of winter. As long as you have the right fuel/air mixture (richer when colder), it should run fine. Your engine probably wants more fuel than it's getting when it's cold. I don't know how that's achieved with a carb (mild choke?). I have EFI.

Yup! It turns out the L wire gets the alternator excited, and then when I unplug the L/S connector, the alternator still puts out. That means when I wiggled the connector, what really made the alternator start working again was my wiggling some internal part. The alternator went back today, and I'll have a replacement Tues. On a side note, I really seem to be going through alternators, each time for a different reason. Just before I bought the car, the PO had his Nissan dealer install a new/rebuilt alternator. I don't know whose it was, but I assume it would have been a quality rebuild. The alternator lasted a few months before the voltage regulator started regulating over 16V. So I got an AutoZone lifetime warranted alternator (yes, I know, cheap stuff) that died a month later. It was rebuilt in Mexico. The next replacement was rebuilt in the US and lasted 2 years before this intermittent problem surfaced. Maybe the third time is the charm?

I've seen this switch come up in discussion before (California models?). I've not seen it. The coolant temp sensor is the part that might be giving you grief with regard to your engine running rich. It doesn't have any wires coming out. Rather, a Bosch 2-pin connector (like the ones on your injectors) is plugged into it. Sorry I can't help with the switch.

Interesting! Well, the light came on while I was driving, so the alternator was already excited. I take it, then, that if the L/S plug had come undone in with the alternator in its excited state that the alternator output would have gone to its max value, instead of zero. I'll try replicating that tomorrow (with the output disconnected from the battery/system, of course). If that's the case, then I indeed have something else going on -- probably a bad voltage regulator board. Fortunately my local AutoZone has enough confidence in my abilities to take my word when I tell them the alternator has an intermittent fault. Gotta love small towns.

Thanks, Zed! Well, it finally occurred to me to simply disconnect the alternator from the battery (i.e. pull the maxifuse on that circuit) and then unplug the L/S wire to see what the running alternator would do. (Duh!) Much to my surprise, it put out NOTHING. Then when I plugged back in the L/S plug, it put out about 15V. So maybe my S connection wasn't making contact after all? I guess I won't wander too far from home and will just see how it goes. Do you have any idea how far I can drive on a fully charged battery to get home, should my alternator fail? I'm glad I get the brake light when the alternator goes down, because that's hard to miss (being bright and being on the spedometer).

Er... That should be "what happens WHEN the S wire doesn't make contact?"

Hi all, My alternator stopped working yesterday. When I wiggled the L/S connector, it started working again. I had assumed it was a corroded contact at that connector. Then I started thinking about it. The L is simply the alt error light signal, which did correctly cause my alternator and brake lights to glow (no bad connection there). The other is the sensing line, which provides voltage feedback to the internal regulator. If that were momentarily disconnected, wouldn't the sensed voltage be zero, and therefore the output of the alternator at its maximum? At the time I was incorrectly thinking of the S as a field wire and thinking, "Ah hah! No field, no output!" I would test this hypothesis by running the alternator with the L/S plug unplugged, but I really don't want to risk over-volting my system. I'm thinking there's a bad connection on the voltage regulator board and that my wiggling the plug momentarily settled that internal connection. Any thoughts? In summary, what happens with the S wire doesn't make contact? Is it maximum alternator output, or is it no output at all?

A heat-related failure would probably occur about the same way everytime, so if the failure occurs sometimes after a half hour, sometimes after only 15 min, sometimes after only 1-2 mi, and sometimes as you're trying to start the car, it's probably not heat related. That said, most non-heat-related intermittent problems won't disappear with the car just sitting for 15 min. It was this last observation that made me suspect a heat-related issue (i.e. when a part gets warm from running), and I suspect Blue picked up on the same thing when he suggested the ignition module. Yes, a new pump comes with a new filter screen, but the screen is very small. There's a much larger intake screen in the tank, at least on a '77/'78. (I don't know about the '76 tank.) Some of us install clear inline filters between the tank and pump. Before you drop the tank, I'd suggest the following: First, see what your fuel flow looks like. Pull the hose off of the outlet side of your fuel filter (the one running to the fuel rail), and attach a long, clear, vinyl hose to it. Run the end back to your gas tank filler neck. Then connect a wire from the (+) of your battery to the (+) post on your fuel pump to run your fuel. The fuel will (or at least should) circulate at relatively high volume and of course no pressure. If you have a restriction anywhere, that should reveal it. Next, you can determine whether there's crud in your tank by removing the round inspection plate in your hatch area over the fuel tank (about 6" diameter, with 2 screws). Removing it will reveal the fuel level sender at the top of the tank. You'll have to use a screwdriver and a hammer to tap on the retaining ring to turn it and remove the fuel level sender. (Vacuum out the area first!) Then you can look into the hole with a waterproof flashlight (no sparks) to see any rust or sediment in the bottom of your tank. Obviously, NO SMOKING, NO SPARKS, ETC! When you reinstall the sender, clean the parts thoroughly, and be sure to align the notch in the sender with the notch in the mount. BTW, one intermittent fuel problem that gave me fits for a while was from a corroded/melted/arcing connection in one of the big wiring harness connectors, just inside the firewall on the passenger side. Pull it apart to check the condition of that one contact. As I recall, it was a blue/green wire in the corner of one of the connectors. I ultimately snipped the two wires out of that connector and connected them with a bullet connector.

Also check the contacts and innards of your dome light to see if they're charred/melted. Mine looked a bit toasty. I sweetened one connection with a bit of solder (carefully, because the parts are held by plastic), and I replaced my incandescent bulb with an LED to radically decrease current demand on the circuit.

It sounds like SOMETHING that's failing because it's heating up. I had a fuel pump go out on me a while back. The pressure would start out strong (enough) and would sag so far that the engine would lean out and stop running. The first time it took 45 min on the interstate. I had the car towed back home, and it started right up in the driveway. Grrrrr. The second time, it took about 20 min around town. The third time was when I hot-wired the pump, put a gauge on it, and watched the pressure. After only 15 min, the pressure went from adequate to practically nothing. Replacing the pump fixed the problem. You can get a cheap pressure gauge from your local Ace/TrueValue Hardware store ($5) and the brass fittings to connect it inline between your fuel filter and fuel rail. It's a handy diagnostic tool to have in your engine bay when you're stuck.

You could buy one for $1000 from Northern Tool: http://www.northerntool.com/shop/tools/product_200401171_200401171 Maybe you could find one used on CraigsList if that's too much. The nice thing about buying is that you can always sell later, so it's not like it really costs you $1000 in the long run.

^^^ What Zed said. Especially check out the coolant temp sensor connections. The CTS is the smaller of the two items screwed into the thermostat housing and having a 2-conductor Bosch-style connector on it. Those connectors at the front of the engine are exposed to pretty harsh conditions and can rot and corrode pretty badly. The CTS, BTW, is "THE" most important influence on fuel/air mixture, other than the AFM, and a weak connection in that circuit will have your engine running quite rich.

I'll do that. We'll be remodeling a home in the near future, so the old oven is slated for the garage.

I can see it now... To defrost the turkey, she parks Lee's Z in the sun and puts the bird in the hatch!

He actually hooked up the thing on an electronic test bench, so it wasn't a HORRIBLY time consuming thing. That said, I bet it did take a while.

Someone, somewhere, hacked an ECU and described how all the resistor values affect the injector pulse. I suppose an ECU could be tweaked that way, but the easiest way is simply to tweak the CTS circuit resistance. We'll tell you how to do that if it becomess necessary

Black after 100 mi? It sounds like your engine might be running really rich. Of course that's not the oil pressure problem, but I'm just saying. Check your plugs to confirm. That might be the reason your engine runs roughly when it warms up. The oil pressure senders do tend to fail. They screw into the side of the engine block near the oil filter -- about the size of a child's fist. You would unscrew the sender to attach a mechanical pressure gauge. BTW, 10W30 is a bit thin for a warm climate. You might want to consider 10W40. That will improve pressure.

Geeeesh.... OK, tip to you guys: Open a few drawers. Somewhere in one of them, you'll find some aluminum foil. Put that underneath whatever you put in the oven. Throw the foil away when you're done. Then run the oven for a while to burn off any fumes (maybe 30 min?). Open the door to let it air out when it cools. This isn't to say your wife won't mind, but she probably won't fume quite as much about it. That said, my partner doesn't have any problem with my baking an occasional part. Of course she MIGHT if I stuffed an entire exhaust manifold in the oven! Eventually I want to have an oven for just such things in the garage. I'll try my hand at powder coating then.