Captain Obvious

That's awesome!

I wasn't trying to send a reminder. I was just trying to help out with the thread. One of the other forums is currently in a tailspin with noobs on one wing asking typical noob questions and longer standing members who have become bitter about answering such questions on the other wing. It isn't pretty. :sick: So you bailed on the AAR completely? I considered this as well but haven't pulled the trigger...

Thanks for that pic. That's a cool shot. The only one of these I have is the one on my car or I would have dissected one. Thanks for taking care of this. I've been working on a fuel presure leakdown issue with my 280 and after fixing a few things I've got it to the point now that it takes about an hour to drop to zero. I've traced most of the remaining leakdown to my FPR and I haven't decided if it's worth trying to make it any better. All I have to do is outlast the temp crest on a hot shutdown day and I think I already have that beat at an hour. Still bugs me though...

Yeah, it would suck to buy a whole regulator assembly just for that stupid washer. Think about it this way... If the only other option is to buy a whole new one, then there's nothing to lose by trying other ummm "creative" methods first, right? And you know where to find me if you want to send me the assy, right? No? You don't? Awwwww. :laugh:

Wait... So if I drink more, I'll forget stuff? Can I decide what goes and what stays? That would be very valuable.

Haha! Note that I've not performed this specific repair. Just looks possible from the pics. Proof is left to the attempter.....

Yup. With the 78 configuration, there will still be junk in the throttle body and intake manifold, but the AAR should be cleaner. Bunch of discussion about such things in this thread: http://www.classiczcars.com/forums/fuel-injection-s30/47309-valve-cover-hose-question.html

Whaaaa? "Permanent?" What is the meaning of this word "permanent"? Carbide burr on a Dremel. Drill and tap the remaining stub and use a small screw and a washer to retain a new wheel.

Making an adapter plate is something I could definitely handle. I'm mostly concerned with getting something that has the same or close to the same bore diameter and already has an air control mechanism installed. I've looked over the stock TB for a location to mount such a device, but I've come up blank. That BCDD takes up the entire bottom side. If it weren't for that... So there's a question for the collective... Every year from 70 all the way through 78 had some sort of vacuum controlled air bleed into the intake manifold. The carbureted years called it the throttle opener, and the FI years called it the BCDD. Did that continue into the ZX years? Did the ZX cars have a BCDD or similar device?

Cool. Sounds like good progress. 78 used alternator output AND oil pressure switch to control the fuel pump. Unless the key is in START, the alternator needs to be spinning AND there needs to be enough oil pressure to close the switch in the oil pressure sender unit. If those two conditions (spinning alternator and oil pressure exists), then the fuel pump relay should close and send power to the fuel pump. The fuel pump relay is located on the relay bracket up in the engine compartment near the battery. It has four wires going to it... Black, white/black, and two green/blue wires. If you separate the connector and the relay and then short the two green/blue wires together at the connector, the fuel pump should run. If shorting the two G/L together doesn't cause the fuel pump to run, then the problem is between that relay and the pump. If the pump runs, then your issue is upstream of that point and could be a bunch of things. Doesn't matter what position the key is in. You can do this test with the key in your pocket. Give that a try and see what happens?

I'm talking about the 280Z intake. Something that uses the same bolt pattern as 75-78. What I would really like to find is something that bolts on and has provisions for an idle air valve of some sort. I'm musing getting rid of my AAR and instead replacing it with something built right into the throttle body. Nice video Blue. Looks almost like a pupil. Wonder what the performance advantage is. Less obstruction when fully open? More linear flow vs position?

What alternative throttle body options are available? Weber (and it's clone). 240SX Q45 Anything else? Anything that bolts up and has the same internal throat bore? What about from other manufactures? Doesn't have to be Nissan...

When it comes to needles and nozzles, tiny changes can have surprisingly large impacts. Just one thousandth can have a noticeable effect.

Kurbycar, Thanks for the input. I didn't get the chance to do any experimentation yet. Soon I hope. See here's one of the problems. I would love to use a higher power higher quality aftermarket head unit, but I've looked at a bunch of aftermarket stuff and I don't think what I want exists... (anymore). Everything aftermarket is loaded with too much crap with tiny buttons on multi-colored distracting dynamic displays. Put the stuff I use the most on the left and the stuff I use the least on the right. Don't put all sorts of crap around the volume knob that I'll hit by accident in the dark. Keep it simple.

Cool. Glad you found the problem. That's why I specifically sald "and lay it against the engine." I don't want no willy nilly hunt. I want it to go directly back to engine ground just like the spark plugs do. You're right... Disabling the low side of the coil is actually a safer way to disable the spark. The reason I suggested the coil wire instead of the low voltage side is that you can do it in an instant without tools. It's faster, easier, and just as safe and effective, if you do it right. I should have been more specific and said "After you pull the coil wire out of the distributor, you'll notice that there is a metal end on it where it connects into the distributor cap. Lay the coil wire against the engine in such a way that the metal end makes electrical contact to a good ground connection to something like the intake manifold or valve cover." Better?

The reason people have suggested an ignition timing issue or plug wires on the wrong plugs is because if you get a spark too early as the piston is coming up, the explosion inside the cylinder will push back down on the piston and fight the starter. If this happens, the explosion will stop the starter spinning very abruptly like you described. Pull the coil wire out of the center of the distributor cap and lay it against the engine. Then crank the engine over while that coil wire is removed and if the problem goes away, then you know it's some sort of ignition timing problem. And I don't think your starter is the problem, but the above wouldn't tell you much anyway. Under a no load condition, I don't think you'd learn much from measuring the voltage drop across the starter. It's more of a current thing than a voltage thing.

And Blue... Mi casa es su casa! I'll show you my newest secret projects in the lab. :tapemouth

Thanks again guys. I'm going to retry my pre-packaged speakers in the Z and make sure I was hearing what I thought I was hearing. I've also got two or three aftermarket head units sitting on the shelf that I could throw in temporarily just to try to see if they sound any better. I'm sure the aftermarkets I have include better output stages than the Kia. Wouldn't solve the problem, but might help me identify if the problem is at the source or the destination. Ironically I've been on the inside of more car stereos than I can count... I was the repair tech at an audio video store for a couple years to get through college. I can make them work, but apparently can't make them sound good!

Shouldn't always be your first inclination, but there are times when it's appropriate, right? You do know that driving around with that can of freeze spray in the glove box will probably be your insurance that it won't happen again, don't you? :laugh:

Mike, Thanks for the thoughts. I did not install sealing around the edges of the board in which the speakers are installed, but it's a pretty tight fit even without seals. I understand the theory, but I believe that level of improvement is in the minutia. I'm no expert on the topic (obviously), but I think I'm looking for big steps first. Short story on the speaker polarity is that I know it's correct. Longer story is that months ago when I did this install, I even went so far as to doubt the accuracy of the markings stamped onto the back of the speakers. So I took turns with each speaker hooked up to a DC source and verified the direction of the cone travel. I can guarantee that I've got the speaker polarities correct and they are all pushing in phase. I've got a pair of pre-boxed speakers (ones with their own enclosure) installed in a different car. In that other car, they sound pretty good. Memory says I tried those boxed speakers in the Z and they didn't sound as good in the Z as they did in the other car, but maybe I should try that again...

I know it's kinda shotgun approach, but I'd pick up a can of that spray cooler stuff and take it with you next time you get to the car. If the problem recurs, I'd pop the distributor cap and give everything inside a quick shot of the cooler and then snap the cap back on and see what happens.

That should make it easier to find, right? Mixture screws don't do that. Stop-n-go driving isn't a particularly high fuel consumption situation. You've got way more fuel flowing through the carb (per unit time) on the highway than you do during stop-n-go. And the temperature things is weird for fuel supply. I'm having a hard time coming up with any sort of fuel supply issue that's temperature related. And certainly nothing that "latches" into a problem state as you've described. Besides, it's not mid-summer anymore. If it's got a temperature related issue at this time of year, what was it like this past summer? I'm thinking electrical... What's in the distributor? Is that the Pertronix?

Thanks much for the help guys! djwarner, The head unit came from a Kia Spectra. Didn't make note of the year, but they used this radio (and like two others that are pretty much identical to it) in almost all the later model single-DIN Hyundai's and Kia's before they started going double-DIN. There are like three single-DIN models that all have the same faceplate functions, but the buttons are moved around to different locations. It's my assumption that the majority (if not all) of the electronics behind the faceplates are pretty much identical. I do not know for sure if there was a subwoofer used in the original installations, but I doubt it. I can tell you however that there are no subwoofer specific connections on the back of the head unit. I can also tell you that if they did use a sub in the original application, it used high level inputs because there are no low level outputs from the head unit. Walter, That's also a very good question, and I do not know the answer. I bought this model because it had the mechanical and human interface features I wanted, but I have no idea how it sounded. For all I know, it sounds just as good (bad) in my car as it did in the OEM installation. Kinda stupid, I know... So if it's just a crappy radio, can I throw additional equipment at it to make it better, or am I back at square one looking for a different head unit?

I'm having a hard time forming a mental picture of what the symptoms are... You're saying that it runs fine when you first start it and it continues to run fine until you do some stop-n-go type of driving? And then after the stop-n-go, you can get onto the highway and the problem goes away all by itself after a couple highway miles?

The speakers are 6x9 Sony Xplods that came with the car from the PO: They are mounted right behind the seats into the 280's false pressboard hatch area floor so there's plenty of volume on the back side of the speakers.. Location is such that the magnets hang right over the cargo hatch recesses. The only amp I have is the one located in the head unit, and to be honest, I suspect that's my problem. My suspicion is that the factory head unit just doesn't have the balls to drive the low frequencies to the speakers and that's why I get no bottom end. However, before I simply start throwing money and equipment at the problem, I was hoping there was some way to confirm what's going on. I know "doesn't sound good" is very subjective, but are there tests I can run? Questions that can be answered? Better descriptions of what I hear that can be provided? You know... The kind of stuff that the audio-geeks live for!