cgsheen

There are three sensors in the thermostat housing: Thermotime Switch (EFI), Temperature Sensor (EFI), Temperature Sender (coolant gauge). The EFI sensors have 2-pin Bosch connectors. The Temperature Sender has a male bullet built into the sensor (usually does not have a wire). The yellow wire that connects to it has a female bullet. There is no "ground wire" on this sensor. The Temperature Sender is cheap and readily available (although all the listings I see are for the sensor only and don't include the nut that goes over the barrel and holds it in place). Thermo_sensors.pdf

ZHoob is correct - there is no "prime" on these early EFI Z's. Not on the NA ZX's either - not until the turbo engine (L28ET) ECCS ECU. And the fuel pump SHOULDN'T run continuously - that means a very important saftey circuit has been disabled or is inoperable and needs to be corrected. That's the switch in the AFM he referred to. It's bypassed in the Ignition START position and power is passed to the fuel pump. In any other ignition position, it's the AFM switch that should provide power to the fuel pump. The logic being: IF air is passing through the AFM with enough velocity to make the vane move, the engine must be turning. If the engine is NOT turning (running) the switch should be open and NO power should be going to the fuel pump. If it doesn't work that way someone has screwed with the circuitry or the AFM is defective. The switch in the AFM is pretty simple (and shouldn't default to ON) - it's more likely that someone has bypassed the safety feature...

No (or not necessarily...). A relay is just an electrically operated switch. It's almost always activated by another switch (switch working a switch - weird huh?). Many of the switches in a Z are "switching" (breaking) the ground wire. Thats the case here. So, the relay coil is powered by the wire from the fuse panel (which is activated by the ACC (accessories) circuit I believe (it's not "hot" continually)) BUT, it's not active (the electromagnet doesn't "work") until it has a ground applied (has a path to ground). The ground comes from the blower switch and passes through all the other control switches in the A/C circuitry (microswitch, thermostat switch, etc.) If any of these switches in line are not "made" (closed), the relay coil is inactive (no path to ground) and it's switch is "open" which simply means no voltage is being passed to the compressor clutch magnet. The relay is a way to control the switching of the compressor ON/OFF with lower amperage wiring and switches while the relay switch provides a higher amperage wiring path to the compressor. The relay itself is VERY simple, the multitude of additional switches and safeties and controls in the A/C circuitry make understanding the circuit more difficult. You probably got lost at the blower switch... (The ground path is: Earth (shown in diagram above as an attachment to the body of the Ignition Relay) B -> Blower Switch -> LW -> LY MicroSwitch -> Y Thermostat Switch -> BG to Connector -> YR Pressure Switch -> Y to Relay. (If you look closely at the Blower Switch, it shows that B -> LW is closed in all fan speed positions and open when in the OFF position.) OK, all the wire color changes don't help either... The Pressure Switch in these cars is a "high pressure cutout". That switch should ordinarily be closed unless the high pressure side (liquid line) of the refrigeration tubing is overly high pressure. That doesn't happen normally if the A/C refrigerant charge is correct, but it's a "safety" that "shuts off" the compressor in an over-pressure situation. It does that by removing the ground connection to the A/C Relay. It resets itself when the pressure drops.

???? A simple relay has a switch and a coil (electromagnet). The coil requires power and a ground to operate. The switch is just a "break" in a strand of wire. In automobiles it can be a battery voltage wire or a ground wire.

The two LY's are +12v power from the fuse block - one is power to the relay switch and one is power to the relay coil, the L is power out of the relay switch (the opposite side of the switch to your LY) to the compressor clutch magnet, Y is obviously the ground side of the relay coil (again, opposite side of the coil than your 2nd LY). That's how you wire up your new relay...

What he said...

Hmmm... I'm running Porterfields and when they heat up, they perform better. Although my Z likes the uphill better, there's this downhill run I take up above Tortilla Flat in the Superstition Mountains. By the bottom of the hill my friction is working it's best - and I've never noticed fade. I'm running vented rotors in front.

I had an MTX-L and it's gauge was never reading the same as the data sent to MS and Tuner Studio. I researched it and found voluminous info on the internet about the issue and how Innovate builds (wires) their controllers. The 14point7 Spartan 2 has an interesting feature to assure that it's output to the ECU is calibrated properly. (the way you wire your install can have an affect on your sensors...) (I also have to say that my L28ET has never run this smoothly since adding MS3X and implementing full sequential COP and full sequential fuel... I thought it was overkill for this old tech engine but I'm loving the way it's running now)

Get a 14point7 Spartan 2 wideband to go with your megasquirt.

Move this post to the "Engine Components/EMS/Megasquirt" Forum and look for "Chickenman" and/or "softopz". Chickenman does remote setups and tuning for a modest fee.

I don't know... I've only seen a couple of 73's and never one with pistons. The 73's we have had in the shop all had bumper mounts like what I installed on my 260. These mounts are substantial, nothing like the earlier 240Z mounts. (I just happened to find a '73 at a pick-n-pull several years ago with fairly good chrome bumpers - whereas my 260 had none at that point...) A person could certainly use that grill on a '73 240Z though.

That's the grill that my early 260Z has... It may be specific to that model because the earlies had pistons in the front requiring the lower 2 slats to be narrower. The early still used the 240Z style turn signals and valence pieces. (I have a 1973 front bumper and bumper mounts on the front and the narrow slats aren't really needed for that configuration...)

I'm very interested in that timing map as well. Looking forward to what you do with this.

Wow... I'm surprised someone didn't do this years ago. (maybe some did, just weren't interested in sharing) Pretty cool, I think. Thanks for sharing!

That's almost correct... Your center vent section is backwards (and upside down I think) - that small rectangular vent showing should be facing the front of the dash. It's easier to put that in place after the dash is installed.

Here's an example of the other vent I was referring to: https://www.ebay.com/itm/70-78-DATSUN-240Z-260Z-280Z-UNDER-DASH-FRESH-AIR-VENT-WITH-PUSH-PULL-OPEN-CLOSE/221205489995?hash=item3380dfe94b:g:kFAAAOxyQj9RTxSD:sc:USPSFirstClass!85281!US!-1 It mounts under the steering column (and apparently there is one under the glove compartment as well...). There are very good diagrams in the A/C FSM section that "jhm" linked above. They show the ductwork and all of the vents available for models with factory A/C installed near the end of the section. I've seen those caps on the small tubing outlet before and I'm wondering if that's how the non-A/C models were equipped.

That's out of a 260Z/280Z dash. It's a "Tee" fitting that delivers vent and/or A/C air to a vent mounted under the steering column. Mine is still up there under the dash but I doubt I can get a picture of it in place... The duct work should be pictured or described in the Factory Service Manual for the 260Z and the US 280Z (at least the '75 and '76 280Z models here in the States). I can't remember if that is a "drivers side only" thing or if there are similar vents on driver and passenger sides - it's been along time since I've seen complete stock ductwork and vent pieces - I haven't ever fully reassembled mine even though I think I still have all the pieces...

No, the Stance USA threaded adapter is not pre-cut for an S30 front hub. If you are welding to the hub, you'd need to notch the adapter as required.

The stock plug on the '74-'76 fits the Kia blower without modification. (I'm assuming the '77-'78 are the same but I don't know for certain) . It has the same "T" configuration 2-pin plug and polarity is correct. Also, there is no way the Kia blower we're talking about will fit right in the stock '74-'76 blower housing. The squirrel cage is slightly larger than the stock opening. The opening needs to be trimmed to get the squirrel cage in.

Flashers do, turn signals do not.

That's what I do. Kinda tough to do alone - get some help. Lube helps too.

You have the wrong collar for your clutch package. If it were correct, the fork position would be pushing the slave cylinder push rod all the way back in (like you're showing you can do with your fingers in the video) - or nearly so. You need a longer collar for your throw out bearing. NewZed hit the nail on the head - the collar needs to be correct for the clutch package (pressure plate height (or thickness))

That spindle pin tool is probably NOT going to help in this situation. I'm with Jester, use a "sawzall" (recriprocating saw - $20 at Harbor Freight if you don't have one) and cut the spindle pin in two places between the control arm and the hub. Then you can figure out a way to get what's left of the spindle out of the hub section. Much easier to press, beat, or air hammer out without the control arm in the way. You're going to burn out the bushings in the control arm so there's no reason to push them out of there... The spindle pin is fairly soft steel so it's not difficult to cut through with a good bi-metal blade.

We've known the guys from Vintage Spirit Garage for years. They are solid dudes, been around for a long time, have turned out some awesome projects, and are deeply involved in the Nissan/Datsun community in California. We've had nothing but good experiences. I was actually a bit annoyed by much of the thread on ClassicZcars... BJSZED - Have you installed your gauges yet? How do they fit?