Zed Head

I think he might have meant 15 minutes. I have a one hour timer and just turn the knob about 1/3, so 20 minutes. If it's still running when I come back I just let it blow while I drive. I have a fuel pump cutoff under the dash also that I always flip anyway, not because my car is worth stealing but because I think it's probably easy to steal. Saab apparently had a delayed-off relay on a few of their models to run an electric fan but they started failing closed so they recommended replacing them with regular relays (I think that have a thermal switch in the circuit also). There are solid-state electronic timers out there but I haven't found one that stays closed for over 5 minutes and/or will run on 12 volts.

Good luck. If you have it all figured out, then what is the question? Just tell the muffler shop what to do. Sign a waiver if they need it so that you'll take liability for not having a converter, since they are federally mandated. There's no way to answer your question since you have a car of unknown origin. My impression has been, in Oregon, if the tag on the door says "Catalyst" then the car has to have a catalytic convereter. If you want to take a chance with federal law, go find a tag that says "No Catalyst" and stick it on there. The shop is going to go by the tag, not what you tell them you think is right.

If your door pillar and dash tags aren't correct, then what would be? The VIN usually follows the frame, and the tags match the VIN. I've heard that the VIN might be stamped on another part of the body also. Not sure where. Does any of this matter? Sounds like you're putting an exhaust system on a car that you won't be able to title and register anyway. Could even be arrested for owning.

There should be a metal tag on the driver's side door pillar that says whether or not your car should have a catalytic converter. My 76 has one that says "Non Catalyst", which is a weird way to say it. Probably lost something in the translation. The converter showed up before 79, Nissan has floor temperature warning sensor instructions for 76 in the FSM. Looks like the O2 sensor didn't show up until 1980 (page EF-28).

Saw this listing on EBay and thought it was funny. Selling the little rubber doodads that get lost when you're bleeding your brakes - Datsun 240Z 260z 280z 280ZX Brake Bleeder Screw Capsnos | eBay

It's hard to diagnose a bad ignition module. I just suggested it as a possibility. Actually though, I'm not sure what you mean when you say the tachometer ("tick hand") isn't working. Looking back at all of your symptoms, they're kind of strange. The tachometer and some of the lights stop working at the same time? When you say "working", do you mean the needle doesn't move, or it moves erratically or the light in the tachometer isn't on? There is a large ground wire connected to the battery negative terminal. Is it intact on your car? Probably best to take a meter and confirm good grounds everywhere.

F54/P79 is a stock 280ZX engine. Any of the 280Z or 280ZX cams would work fine, they're all very similar. You'll need one that's internally oiled since you don't have spray bars. The N42 head is completely different from the P90. The P90 is very similar to the P79. Carbs or EFI?

Even in 1983 the system was still primitive. An earlier FSM might be helpful, like 81. The later FSMs seem to be written for use with an electronic tester which nobody has anymore, if they ever had one to begin with. The ZX EFI systems are more complicated than the early Z's. You might start another thread with a more descriptive title. Cold start issues are boring, and that's not your problem anyway.

You said that it starts cold but will only idle until warm. So "cold start" doesn't seem to be the problem. Cold running is the problem. The cold start injector only operates when the key is turned to Start. Add more details. Did you install an 83 engine? Did you re-install all of the hardware, including emissions equipment or did you leave some things off? Are you using all 1983 intake, exhaust, AFM, etc. or did you use parts from the new engine? By 1983 Nissan had a lot of things interconnected for emissions and mileage. If one thing doesn't work right, sometimes it affects other things also.

Well, that's interesting because the tachometer and the ECU both get their signal from the negative post of the coil. So, in addition to whatever is going on with your connector, you should check connections at the coil and ballast resistor. You might have a loose connection there. It could also be that your ignition module is going bad. That will cause your tachometer needle to jump around too.

What the heck is the tick hand?

I've heard of the valve heads "mushrooming" or "tuliping", probably just before they break off. Valve seats also can wear down until all of your adjustment is gone, apparently. Since you know what you're doing, you are probably thinking also that it might be best to fix that before the head breaks off and does more damage. Plus your "fix" doesn't really make sense. If you couldn't loosen the nut enough to get the valve to seat correctly with lash, there's no way to guesstimate a better spot by making it tighter. It needs to be looser. A cylinder pressure check might show you something.

Was the suspect valve on the base circle? You should read up a little on how to adjust valves. You might have just opened that valve up and are in the process of burning/warping it or it's so far open you've lost a cylinder (no compression). The proper valve adjustment process is described in the Engine Tuneup chapter of the FSM. Your current method is way off.

Ah, the engineer's esthetic (no offense, I feel the same). Unfortunately for us, aftermarket parts are usually not as-designed. Just sayin', it's one of those realities. Anyway, to the PO, you might check under the rubber boot for fluid. It might be the cylinder itself that is leaking.

The fitting on the slave cylinder is a straight thread, not a taper, (I just looked at my spare cylinder) with no seat for a flared tube end either. Seems like it would benefit from a washer unless they did some precise machining on the flat seating surfaces. Maybe the factory parts are of higher quality than aftermarket. My car came with a copper crush washer, although I don't know if it's stock. And good old carpartsmanual.com shows a washer, but, oddly, it's on the end of the hose that does have the typical brake line flare fitting. Why the "please" on no washer? Datsun 240Z/260Z/280Z Clutch Control Hose and Nisan sells the hose washer GASKET-HOS :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com

Stupid cat...

Seems to me that if the heads flow well from the valve openings to the manifold surface, that constricting flow that soon will negate much of the work. On the other hand, if the "work" at the manifold surface is not matched in the bowl, and around the valves (unshrouding), then it may not matter anyway. I know that you shouldn't have flange at all projecting in to the flow path, not even a piece of gasket. It will create turbulence and ruin the flow. Who did the head work, it seems like they would have some recommendations? I looked at your Resto thread but don't see any mention of engine work. Don't forget to check the collector area of the header. If the flanges look like that it wouldn't be surprising to find a major clog at the collectors also. That header doesn't even look good for a stock head does it?

The idle speed screw actually controls air flow through a bypass channel. Turning the screw out (counterclockwise) increases idle speed. The AFM screw just controls the air/fuel ratio, at very low air flow (low RPM). It might affect idle speed but only indirectly and not much.

How does the ZX do with the use of a timer? Better than the thermal switch? Thanks for those links. I followed the second to Walmart - Find the Attwood Turbo 3000 Blower at Walmart.com. Save money. Live better. Fits my budget better. Looks like it might be okay mounted on the firewall. Summer project.

I wanted to get cooling of the fuel rail out of the picture. Isolating variables. There are only four air streams (four of the injectors are paired up) pointed directly at the injector bodies, underneath the rail. Plus the ZX mounting scheme, with the blower bolted to the side of the engine and the ductwork over the valve cover, is bulky and difficult to work around. In this setup the blower is off of the engine and the cooling tube can be slipped off and removed easily. It just lays on top of the engine under the fuel rail. The only attachment point is the slip fit on the blower nozzle. It's an experiment cobbled together from available parts.

After absorbing all of the ideas on where the heat soak problem originates, I decided to try the most direct solution I could fabricate and blow air directly on to the injector bodies. I have a ZX fuel system blower fan and ductwork from a ZX motor I had bought in the past but didn't want to use the bulky ductwork or the thermal switch (which doesn't seem to be effective on the ZX's anyway). So I bought a bathroom fan timer from Home Depot to control the fan (one hour range), and went to the wrecking yard and scavenged two 18" pieces of pre-heat tubing from a couple of 80s-90s Chevy S10 exhaust systems ($3). Taped the two pieces of tubing together, cut 6 holes in it over the injectors with an X-Acto knife, blocked one end and taped the other to the elbow from the ZX ducting which fits the blower nozzle, and mounted everything in the engine bay. The new ducting sits nicely under the fuel rail. It's made for the high heat environment of an exhaust system so should be fine. I zip-tied the blower to the condenser for my AC system, and the timer to my steering column. Considering its overall ugliness, it all fit in pretty well, even the timer on the steering column, and is mounted solidly. The pre-heat tubing will take a bend and hold it without collapsing. I used metal foil ductwork tape (Nashua 324A) on the tubing. There are probably better ways to do it, but I was in prototype mode. I've had it in for about two weeks and not had a single hot-start problem. But today I went in to Office Depot, after a fairly long drive down the freeway (hot engine and it's close to 60 degrees here today), and when I came out I realized that I was in the dreaded 10-30 minute zone and had forgotten to turn the blower on. I started the engine and had one of the worst heat soak problems I've had all winter. The engine chugged along on what felt like 2-3 cylinders for a good 1-3 minutes, which felt like 10-20. It finally settled down enough to leave. I went down the block to another store went in for about 15 minutes but remembered to turn the blower on, came out and it started right up like it was cold. Just passing this along for anyone that wants to try it. The air coming out of the holes shoots forward so mount them behind each injector to get good air flow on the injector body. I would take a picture but my engine bay is not meant for looking. I'll post a few links to parts instead. I'm trying to find a dependable automatic timer relay that will turn the blower on when the ignition is turn off but haven't found a good one yet. http://www.amazon.com/Standard-Motor-Products-Pre-Heater-Hose/dp/B000C7UPQU/ref=wl_it_dp_o_pC_S_nC?ie=UTF8&colid=30R38L6H5WA0Q&coliid=I2PEPLP3OQMVN8 GE In-Wall Spring Wound Countdown Timer-15304 at The Home Depot

The ring at the AFM is actually one end of a two-ringed wire. One ring on the AFM body, one on a mounting screw. The Engine Fuel chapter has a decent diagram of the grounds for the EFI harness, from the ECU. Doesn't show you where the connection is, but you can verify them all at the ECU connector..

Your local Nissan dealer might have or be able to get one. If not, Courtesyparts shows stock - Datsun 240Z/260Z/280Z Engine Electrical & Fitting Parts COIL-IGNIT :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com

Just happened to be browsing a book on turbos tonight and found a picture of a typical "floating-bush journal bearing" that looks just like those "brass" parts. Maybe someone blew up a turbo in the past. The book is "Turbocharging Performance Handbook" by Jeff Hartman, picture on page 113.

You're probably on a better track now anyway. By the time I got done with my charging system, I ended up at just the basics of finding a good voltage source for the S wire to monitor voltage, the L wire which comes through the Charge lamp, and the main charging wire for the battery after it runs through the fusible link. All of the original regulator wires are unused now, except the L wire. On the 76 system a problem I found that's not covered by the various internet schemes is that the brake check warning lamp relay power runs through the external regulator. It's yellow and runs back in to the harness. You can end up with it powered always or not powered at all, both wrong if you want it to work. You'll know that you might have this problem if you get a small spark at the negative terminal and hear a relay click when you reconnect the battery. That's another issue though, I don't know if 75 has it.