cgsheen

I'm using an '81 harness - no Fuel Pump Control Modulator... (does nothing other than control voltage to the fuel pump) Sounds like time for a replacement coil/ignitor.

Take all the wiring you can... I had a donor when I swapped my 260 (a non-EFI frame) and it helped me a lot to see how the harness came out of the 280zxt. I actually pulled the fusable link box from the 280zx and the EFI and Fuel Pump relays from the passenger fender along with most of the associated wiring. You don't NEED some of those parts - you already have the fusable links and relays - but it will help you understand how the turbo engine is connected and what you need to do to mate it with the older Z... Look over the FSM for the 280zxt before you go, it has the layout of all the harnesses and a really good description of the ECCS System and what it's components are. You need the coil and ignitor and all the wiring connected to it. You need the turbo's fuel pump or an aftermarket unit. You also need a turbo (or better) clutch and pressure plate. You may want the exhaust back to the Cat. I used the 280zxt boost sensor AND boost gauge in both my Z and my son's '76 280. I pulled the clock out of it's housing and installed the 280zxt gauge in it's place. It's a custom job but it actually looks like it belongs...

You're probably talking about "EFI Connector #2" in the wiring diagrams. It comes out of the ECU wiring harness near the ECU. If you look at the hand-drawn diagram from your other post, it's the 8-pin connector in the top left corner of the first diagram (it's also "labeled" "2" underneath it - may not be clear to someone not familiar with these diagrams)... The connector probably should have all 8 wires, but you are only concerned about a few of them anyway: - Ignore the 2 wires that are for the "speed sensor" - your car doesn't have one! - The wire labeled "inhibit sw(itch)" should probably be called "Transmission, Neutral/Park Switch" - IF your manual tranny has a neutral switch (my son's T-5 has one AND a reverse switch - my Nissan 5-speed does NOT (only a reverse switch) you can connect it to this as a "safety" - the ECU won't start the engine unless the tranny is in neutral. - IF you are using the "Fuel Pump Control Modulator" device, the "Shield" and "B" wires on one end of the plug will be important. My harness is an '81 and didn't use this device (my #2 connector is only 6 pins). - VERY Important is the YELLOW wire next to the GREEN/BLUE wire. It runs to the Starter SOLENOID. (marked "starter 12V" on the diagram) - VERY Important is the YELLOW/WHITE wire next to the Y wire I talked about above: It goes to the COIL TRIGGER (2-wire connector on the ignitor next to the coil - 1 BLACK/WHITE wire, one YELLOW/WHITE wire) - YELLOW wire on the other side (between 2 BLACK wires on either end) - ties to the A/C solenoid wire. It tells the ECU "the A/C is ON, increase the RPM a bit!". I have A/C. I don't use it, but it's easily connected... (YELLOW/WHITE wire next to this one is for the "speed sensor" - so you ignore that one too.) IF you don't have all these wires, DON'T sweat it - as long as you have the ones I've labeled "important"...

It's the ECU that "switches" the fuel pump relay on and off... If the ECU isn't working, the fuel pump will never come on unless you jump it's relay. You need a friend nearby with a working turbo swap or a running 280ZX Turbo so you could try your ECU in their car... If you have +12v to pin 35 (and pin 27) on the ECU and GND on pin 36 (and pin 28), the Green LED should light, and there should be +12v output on pin 16 for ~5 seconds when the IGN is turned to the ON position...

When you convert you really need to remove as much as the original compressor oil as you can from the system and replace it with an R134a compatible oil. The oil moves through the system with the refrigerant and R134a doesn't transport the oil used with R-12 well. In an existing R-12 system, it's unreasonable to think you'll clean all the old oil out - you don't need to. You just need to insure you get enough PAG or other compatible oil into the system to protect the compressor. So, once you get the R-12 out, you'll need to crack the system open. I've never had a good conversion result without pulling the compressor and getting as much of the old oil out as possible. Oil collects mainly in the compressor itself and in the Receiver/Dryer on the passenger fender wall. Most A/C guys will tell you to always replace the Receiver/Dryer with a new one whenever you open the system. It's a very reasonable precaution as it's the filter that protects the entire system... They also make some conversion products that contain oil and additives to help neutralize the acid that may form in an old system - look around at the auto parts store. I didn't change the Receiver/Dryer (also called the Accumulator) on either my Son's 280 or my 260. Just got as much oil out of the compressor as I could and replaced it with a like amount of PAG. Once that's done and the system re-assembled, you need an A/C vacuum pump on it for about 30 minutes pulling about a -30psi vacuum to remove all the condensables. Then it can be refilled with R134a. It should take slightly less R134a than the original R-12. Personally, I don't go by volume, I go by the gauge pressures and temperature performance... It's not difficult, but you DO need the right tools (including a vacuum pump and an A/C gauge set)

From the '81 Turbo Supplement

The green LED in the ECU lights as soon as you switch the IGN to ON if it's powered (and operating) correctly. The Factory Service Manual (FSM) has detailed diagrams and a complete ECCS trouble-shooting section... Even without the Nissan "Consult", you can test everything. Most important is understanding the wiring and wiring differences between the earlier Z and the S130 ZXT the engine came out of. Probably the only practical way to test the ECU is to swap it into a running car. Following the ECCS trouble-shooting guide, there are MANY things you can check on the ECU and it's input/output pins... The condenser wiring from the coil location to the distributor will NOT cause the ECU to be powerless. Both Mine and my Son's L28ET swap will operate properly without the condenser connected to the dizzy.

The stock A/C in my early 260 fit perfectly with the L28ET swap. No reason it shouldn't, all the A/C lines are well out of the way of the engine / exhaust and the L28ET isn't THAT different. Converted my A/C to R134-A and it works much better than I expected. Still need a blower that moves more air through the vents, but I can get < 20 degree air out of mine (on a 100+ degree day here in Phoenix... It's a dry heat!)

I need the Hazard / Defogger wiring harness, switches, and lights (complete). This is the harness that goes from the connectors beside the blower motor, along the left-side passenger footwell and into the center console. Mine had no console when I got it - the connectors are still there by the blower motor, but the wire bundle leading to the console has been cut about 6 inches from the connectors. Mine is a '74 260, but the connectors look just like my son's '76 280... I bought a brand new console from Tustin Nissan! (Great price, Genuine Nissan part - highly recommended if you need a console!) Now I need to plug all those holes and get my hazards working! We don't use the rear defogger much here in AZ, but it'd be nice to have it complete...

OH Ya! You'll find many a problem you may think "mechanical" will turn out to be "electrical"...

There's a 240 at the Pick-n-pull in Chandler you may want to look at...

You need to go to carfiche.com (or xenon's site) and download the 280zx FSM and go through the turbo wiring diagram. The ECU and parts of the EFI system are powered through the EFI Relay. That Relay is powered through the IGN Switch. The ECU controls the Fuel pump and the Ignitor, so you need to make sure the ECU is powered properly. Basically, the EFI wiring on a 280ZXT is this: Main power (+12V) is from 2 wires (one green, one brown) that run through Fusable Links near the battery then across the firewall to the ECU (EFI) harness. (Plug #1, near ECU, 2 wire connector) - Green wire runs direct to ECU (through the 17-pin (3 row) connector) & to the Injectors. - Brown wire is "supply" voltage to the EFI Relay. The EFI relay is switched ON by the position of the IGN Switch. It's the Black/white wire on the IGN Switch that "turns on" the EFI Relay and routes +12V from the Brown wire to the ECU and other EFI components (through a Black/white "feed" wire from the relay.) That B/w wire goes to the 16-pin (2 row) connector on the ECU (2 places right across from each other) and also to the: VCM soleniods, the Crank Angle Sensor, & Fuel Pump Modulator. Most of the other wiring in the harness is "internal" - just between the ECU and it's EFI components. The only other "external" connections you should worry about is the wiring from the ECU to the Fuel Pump through the Fuel Pump Relay AND to the Ignitor. Fuel Pump Relay is "switched on" by the Blue/Red "LR" wire shown in the diagram - it originates on the larger of the 2-row ECU connectors (about mid-connector). Again, it's the ECU that turns the Fuel Pump on and off... The Fuel Pump Relay gets it's supply voltage from a Fusable link near the battery (White/Black wire "WB") so it's always powered, and it's "feed" voltage goes to the fuel pump (and, oddly enough, to the Air Regulator on the top front of the intake manifold...) through a green wire. The Ignitor is fired by the ECU using the Yellow/White "YW" wire in the diagram. It connects directly to the ECU nearly opposite the BR wire I talked about above - on the same ECU connector as the BR wire that controls the fuel pump. If your Z is pre-EFI it won't have either of these relays, you'll have to install and wire them...

After all was said and done, I wish we had removed those from my son's '76 280 while we had the original engine out... They just got in the way with a stock L28ET swap. If you have any cold-air or charge piping in mind, it'll probably be a lot easier with those gone. You're never going back to an L28E AFM, are you? Didn't think so...

The ECU controls the fuel pump (through the fuel pump relay and the fuel pump modulator). It also controls the ignitor. If the ECU actually DID get "reverse voltage", it's probably fried. The ECU gets power through the EFI relay and I'm not sure if that relay would work with reversed voltage. But you may need to get out the electrical diagram and see what could be affected.

First, you know that no 240Z came from the factory with a 5-speed transmission. That doesn't necessarily mean your transmission doesn't fit! My 74 260Z has a 1983 engine (from a 280ZX) and a 5-speed transmission from a 77 280Z... Here are a couple of pictures, the first one shows the original L26 engine coming OUT of my car - it has a Nissan 4-speed attached (if not the original tranny, it's a least "period correct"). Looks alot like how yours is mounted, ya? The second picture is my '83 L28ET with the '77 5-speed attached. You'll see the only real difference is the 2 aluminum brackets I used on the lower part of the bell housing. They came on one of the engine/transmission donors that my son and I have had over the years.

I'll swerve to miss you!

1. Mine too. I've thought about replacing the brake booster over the last year and a half (my kids think I'm crazy that I haven't...) but I just capped the Vac line to the servo... I'm an old guy and "power brakes" weren't all that common when I learned to drive (disc brakes came even later...). Personally I like the feel and I can still stop this thing on a dime so I don't really need the booster. 2. The Tach signal comes off the blue wire to the coil from the transistor Ign unit. Blue wire tees off to a big square resistor about the size of your fingertip, through the resistor to the Tach... (Pretty sure the resistor in mine was visable outside the Dash wiring harness under the glove box.) 3. Some adjustment on the rod that engages the clutch master cylinder - a PITA to get to under the dash - on the top of the clutch pedal. If there's not enough adjustment there, Main adjustment is inside the bell housing behind the throw-out bearing fork. There's an adjustable "pivot bolt" that needs to be set correctly before the tranny gets mounted... No adjustment at all on the 260Z slave cylinder. (although my manual says early 240's had an adjustable push-rod on the slave...)

Hey fellow 260 owner! Better get the Factory Service Manual. The electric fuel pump has 2 cut-off relays (under the passenger side dash with all the other relays I think). One is controlled by the "N" signal from the voltage regulator (so when the engine spins over 400 RPM (and spins up the Alternator I imagine) it "knows" the engine is doing more than cranking...). The other one "senses" the starter engagement and holds the fuel pump off when the starter is engaged. They run in series so either one (or both) can keep the pump from working. Now I'm really glad mine is controlled by the ECU through one relay!

Just looked thru all my dismantle photos to see if I had a good shot of the Dizzy itself - not so much... Here's a pic of the coil and condenser - exactly how it sits in an '81 280ZXT. It comes off the Black/white wire that runs to the coil - through the condenser - and then runs to a spade on the distributor. It definately does on my '83 engine (but it's been a couple of years since I pulled the '81 engine - I don't have it anymore). My dizzy has a spade for that wire - front side just under the lip... As I recall, My son's '76 280 (before the turbo swap) had the same layout - I'm pretty sure it's the same for all the EFI Z's. As I understand it, the condenser is used to reduce electrical noise on the EFI wiring (signal wires to the ECU). Don't know if it's absolutely critical, My son and I both use the condenser as shown in the wiring diagram, but our engines also seem to run fine if it's not connected...

That sucks... I learned LONG ago to always mark original alignment before making any changes on stuff like this. Whoever broke open the AFM's we have obviously didn't know that rule... My son's L28ET idles/accelerates/cruises the best (by "feel") - his engine really does run nice... And it has for the past 2 1/2 years since we did the swap. But I've been struggling with mine since May - It's close, it's still not "there". I've been through everything else and I hoped there was a way to get the AFM "spring rate" back to factory settings. (then, if needed, to start making adjustments from there)

What's the best way to get a stock AFM BACK to it's original settings? Every single L28ET AFM I have (and/or have seen) has been opened and messed with. I have no way of knowing if the spring tension has been changed or by how much...

Besides getting the 3 plugs back into the ECU, you also have the 2 other connectors (Labeled "2" and "3" in the FSM Turbo Circuit Diagram) plugged back together? One of them feeds the Coil and ignitor... (You used the coil harness from the '83 ZXT?) The ECU controls the ignitor on the signal from the distributor so double check the 4-pin dizzy connector to the ECU Harness... You really haven't given much background, so I'm going to ask some stupid questions - The ECU gets power from 2 sources: Both are connected to battery through fusable links - one Green, one Brown? (Brown powers EFI Relay, Green powers Injectors and ECU Injector circuitry) You know your injectors open? The L28ET injectors make a distinct clicking noise and it's easily heard if you know what you're listening for. (Mine were original, had been sitting unused for who knows how long and were mostly all stuck shut...) Electrical connectors seem to be a weak link on most Z's - mine definately were... Double check / clean your connectors. The stock L28ET ECU controls the fuel pump like this: At IGN on, it runs the pump for 5 seconds and then shuts it off. It won't power the pump again until it gets signal from the AFM that air is moving through it. (engine cranking or running) You've double checked the fuel feed and return to make sure they're connected correctly? I made the rookie mistake of having them backwards once... The only thing I could think of that would make noise is the fuel regulator on the injector manifold.

I think all S30's have the same Tach setup. My 74 260 and my son's 76 280 both did... When we did our L28ET swaps, it was just a matter of tying the lead from the turbo coil back to the original wiring. On ours (originally) it's a blue wire from the Coil negative side that's pretty much the end of the engine bay wiring harness. That harness starts under the glove box (passenger side cockpit) - (which is where you'll find that rectangular resistor, by the way...) goes through the firewall near the battery, continues along the frame up to the front of the car, along the frame in front of the radiator, and down the other side to the coil... On the S130, the wiring to the coil is on the opposite side. It's a small harness that disappears into the fender well near the coil and travels back to the cockpit by the ECU (at the drivers feet). It doesn't really matter if you used that small harness or not. You just need to get a connection from the negative port on the coil back to that resistor. If your original engine bay harness is there, just use the blue wire that ran to the coil originally. If you're using the S130 coil harness, take it's blue wire from the coil and connect it to the BLUE wire on the rectangular resistor (NOT the Blue-White wire - that goes to the Tach). The resistor is easy to spot - it's almost as big as your finger, in a rectangular case, and usually wrapped with black tape near the wires... (BTW, "carfiche.com" has the '77 FSM (and the '82 280zx FSM)... Just looked at the circuit and wiring harness diagram - as far as the tach and coil go, it's basically the same as my son's '76 280 (and my 260...))

It has to be an aftermarket A/C unit. The 260 was the first Z that came with factory A/C... (and it's on the left (intake/exhaust) side of the engine - not the alternator side of the engine)

Ya, there's a way around the Pitbull too...