Captain Obvious

Anyone got a recommendation for a good replacement PCV hose? (The one that runs from the front of the block under the intake manifold to the PCV valve.) Does anyone make this in silicone?

I just remembered about the upcoming Carlisle show and I've missed the cut-off for pre-reg. Is there a way that I can I still bring my car to the display field, or is it too late?

Well it sounds like you run very, very rich when you coast at high RPM. So rich, in fact, that you're beyond a mixture that will ignite and you're pushing clouds of atomized gasoline mixed with motor oil out the tailpipe. So you should look for things that would add fuel or oil to the party. Worn rings, valve seals, and maybe a specific kind of head gasket failure could all offer oil. Non-functioning or improperly adjusted BCDD or AFM could encourage extra fuel. So could a faulty FPR, leaky cold start valve, or injectors. But of all the items listed above, the BCDD is the one that is supposed to help with exactly that kind of "extra rich mixture at high manifold vacuum" emissions, so that's where I would start. You familiar with the carbs used on the earlier Z's? If so, think of the BCDD as the fuel injection equivalent of the older throttle opener servo that pulled the throttle open when you coasted. The BCDD essentially does the same thing.

Yup. We're on the same page now... Comes down to the tradeoff between originality and functionality and that's your call. So the OD of the original fuel line is larger than what you find today in the parts stores? So much so that you're thinking the original clamps might not fit well? You don't need it for the application, but the hose rated for fuel injection is usually a little larger than the stuff not rated for it. I think they might use an additional layer on the FI stuff due to the pressure and permeability. In other words, you don't need the FI line for performance, but maybe you could simply use it for the OD? :bulb:

Occurs when you have high manifold vacuum. That's why it only happens when decelerating in gear. Higher the RPM the worse it is, right? How's your compression? Do you use oil? Is your BCDD working properly?

I'm not far from Pottstown. I'm no Z car expert, but I'll do what I can if you get stuck.

Gotcha. But to be honest, the original clamps that you have out for plating weren't what I was suggesting you use. The clamps that I was recommending are the ones Nissan used on the later fuel injected cars (and are still using today). They have a solid band (like the ones you are currently using) and don't cut into the fuel hose like the typical American style "hose clamp" with the slots in the band for the worm gear. They look very similar to what you have on there now, but they are made from stainless instead of zinc plated carbon steel. In other words, I was recommending the solid band clamps, but just from a different vendor. However... It sounds like any clamp that isn't year correct is temporary, right? I didn't know you were aiming that closely at originality. Sounds like originality trumps functionality here, and that's great too! And BTW - Please don't let all this talk about something as mundane as a few tiny hose clamps take away from the beauty of the big picture!

It's conceivable that if the ambient air temp is low enough that the AAR wouldn't be able to maintain enough internal heat to keep itself closed. But I don't think that should be happening at 80+ air temp day. If your AAR is opening and raising your idle while you are driving on an 80 degree day, then I think there's something wrong inside your AAR. Have you tried other AAR's to see if you get the same reaction? I'm with siteunseen... I don't have the heat plate under my AAR and mine doesn't do that.

Hi Wayne, Awesome. Thanks for the help! Out of curiosity while I got you here... There is a device on the dwg called the "Timer Unit Belt Warning". It is located to the left of the fuseblock and is near the new ground you just added. You have all the connections to it listed as US only, but the 77 FSM that I have makes no distinction for that module based on vehicle destination location. So, is there another document somewhere that lists that module as USA only? Thanks again!!

Haha! Yeah, and so are two resistors used as a voltage divider

Excellent! That's awesome! I'm surprised (but very pleased) that the damage was confined to that resistor. I'll take another look at my notes this evening and see if I can come up with any theories as to what could have caused that. I don't remember off the top of my head what part of the ECU that resistor is associated with. Keep that other ECU on the shelf in case there are any issues in the future. It's good insurance. So how's this for a small club to belong to... Has anyone else here ever done successful component level troubleshooting inside a 280Z ECU? Anyone?

Haha! They call me Captain Obvious! :laugh: I'm not holding out lots of hope that simply replacing that resistor is going to fix it. I don't know what happened that fried that resistor, but it clearly wasn't pretty. I'd be very surprised if the damage was isolated to simply that resistor, but it doesn't hurt to try. After replacing that resistor (and verifying that there aren't signs of heat elsewhere), you can do a very basic "reality check" on the ECU on the bench without having to install it in the car: Connect ground to pin 5 Connect a FUSED 12V supply to pin 10. The fuse should be 2A or smaller. The ECU should draw less than 1 Amp. If it draws more than that and pops the fuse, then there's still something wrong inside. If you are at all unclear on how to do the above, then don't try... BTW, it's not a computer. There are no programmable devices inside. It's all analog.

Here's one of those poorly written broken english Craigslist ads with no pics: ALFA ROMEO DUETTO SPYDER 1969 But the price indicates it might be something interesting. Of course... There are ads like this too: 73 240z

Leon, Looking at your pics posted above, the colors of the resin in your two pics appears very different. Is that truly the case, or is that a factor of the camera and/or lighting at the time the photo was taken?

Forget about the reverse polarity stuff... I took a refresher look at my notes and reverse polarity shouldn't fry that resistor. Haven't looked deeply enough to guarantee that something else might fry, but those two wirewound 15 Ohm resistors should be OK. Actually, there's something to check... There are two spherical glob shaped zener diodes with red stripes on them. One of them is visible in your pic (ZD101). There's another one near the other wirewound resistor (ZD201). Measure the resistances of those two zeners in both directions when you get a chance. Use a low Ohms scale. With that resistor fried, it's possible that ZD201 (the one NOT visible in your pic) took a hit. And after that... I'm not going to get into component level troubleshooting of the board. It's going to be impossible on-line.

Sorry. I get it now... Up above you said that you'll stick to refurbishing those emblems that just require a new plate of chrome and some paint. I read that and thought you meant you would do side emblems that were in good enough condition that you could get away without replacing the fill. But in fact, you meant that you wouldn't mess at all with the side emblems because they had that fill... You would only mess with emblems that had plate and paint, with no fill. I'm with you now. :stupid:

Blindingly beautiful. Only other comment is that if I'm not mistaken, you've got full band style aftermarket clamps on the fuel lines? If that's the case, I would recommend replacing them with Nissan clamps because the Nissan hose clamps are stainless while the aftermarket stuff is not. I know... Tiny point to be made about near perfection!

Don't get hung up on the composition or the exact value just for a test. In other words, just to test "Dead" or "Not dead" on your ECU, it doesn't have to be wire wound. It also doesn't have to be exactly 15 Ohms. Just for a test, any resistor between say, 10 and 20 Ohms regardless of composition should work just to see if there are other problems. BTW - There's another identical resistor in there, closer to the big wiring harness connector. How's that one look? I'm trying to come up with situations that would have fried your resistor and one of them is reversed polarity to the ECU like maybe having jumper cables connected backwards? If that were to happen, there would be damage elsewhere on the board, including the other 15 Ohm wirewound. Do you see signs of heat anywhere else inside the ECU?

Gotcha. If the boat tail is a requirement, then you're painting yourself into a beautiful corner. Aluminum block and head, wet cast iron sleeved, chain driven DOHC hemi with direct tappet driven valves. The clatter is hypnotizing. The whine of the gears. The smell of the seat foam. The 'snick-snick' of the gearshift. The way it flits through the curves... The way the heater doesn't work for shat. The constant voltage regulator and generator replacements. The carb percolation. The faded sun crazed plastic on the once beautiful dash gauges. The seats from an era before headrests and shoulder belts and where the recline mechanism is an adjustment screw on the bottom. You either get old Alfas or you don't. If there's anything I can do from the eastern end of PA, LMK.

Haha! Yeah, It's dead Jim. As for replacing it... I don't have high hopes for that. I believe that resistor is part of a protection circuit indented to prevent damage to other parts of the ECU. If that resistor burned open, I bet other parts went as well. Worth a try, but I'm not holding my breath. Might be a good idea to put a couple amp fuse (2A) in series with the FI power coming off the battery. With the injectors not firing, the ECU draws less than 2A, but the stock fusible links will pass much more than that.

There's a lot of love for the Duetto and the prices reflect that. You're probably already aware, but you can get basically the same car with the Kamm tail for much cheaper. I think the Duetto ended in 69 and the vertical back Kamm tail started in 70. Cheaper, but doesn't carry the same "mystique" as the Duetto. If your wife doesn't care, then a later Kamm tail might suffice. Forgot to mention it before, but I've not heard good things about the SPICA fuel injection system. Everyone is always screwing with it and bitching about the unreliability and lots of people pull the whole system off and throw on a pair of Webers instead. However, with myself being a flat top carb proponent, I'm sensitive that there may be different views on that situation. I looked at my books and I don't have anything new enough to cover the Duetto. All my info is from back when the Spider looked like this: :kiss:

Haha! I've got everything I need to test the epoxy method except for the tint. Send me an empty emblem along with a small tube of red tint and another tube of yellow, and I bet I could make a pretty good imitation! About the chrome plating... The chrome plating runs under the filled area, doesn't it? Is it going to work to replate with the original fill in place?

That resistor is supposed to be a 15 Ohm wirewound. Before you yank it, measure it's resistance. Just because it got hot, doesn't mean that it's burned open. Might be, but check first. You can measure it in circuit. Just probe right across it. In other words, you don't have to take it out to measure it.

Neat. Never noticed that. My PO "shaved" all the emblems off my car so I don't see them frequently. Looks like they potted the recessed area around the "Z" with a self leveling thermoplastic of some sort. You should be able to recreate that pretty easy using clear epoxy that has been tinted to the proper shade. Use a slow curing epoxy that has time to level, and tinting compounds are readily available. The biggest issue would be that the air entrained during the mixing action will cloud the compound and you would have to get the air out. Use a bell jar and a vacuum pump to pull the air out of the mix. It'll froth as the air is pulled out, and after the frothing subsides, you'll be left with an optically clear fill material that you can pour into the recess. "Proof, of course, is left to the student." PS - I'm not a plastics engineer... :classic:

And, I've still got some old books and repair literature, etc that I would be more than happy to send you if you pull the trigger and buy something like that. Just LMK.