NewZed

There is a whole series of diagrams in the FSM AC section that show how everything works. Sounds like your water cock might be jammed though. Moving the lever to heat should open the valve and let water flow. Are you sure that the hoses to the heater core from the engine are connected? They get blocked or bypassed by owners quite often when the core starts to leak.

What about the other knob? AC Vent Fresh, etc. It matters.

Wouldn't the impeller diameter be the number that matters? The diesel impeller is larger diameter? No need for eyeball estimates then. The RockAuto picture looks like a gas impeller in a diesel housing. To my eye. Taking parallax and other photographic distortions in to account. Edit- maybe this guy can take a measurement...

No, it's not difficult. But you do have to devise a spacer that will fit inside the case and around the Maxima shaft since the clamping surface on the Maxima alt is recessed . Plus the flats on the interior of the pulley (a 78 pulley anyway) need to be rounded out to fit over the Maxima alt shaft. And, if you want the pulley center to be in the right spot, you'll probably have to relieve the Maxima case of a small amount of material, otherwise the V pulley will rub. And you'll need a different nut, since the Maxima nut has a recess inside before the threads start. You'll end up with one or two threads for clamping otherwise. Someone recently noted these problems in a different thread also. Just saying, it's not a straight bolt-on.

The 77 external and the ZX internally regulated alternator both put out 60 amps. The turbo alternator was rated at 70, but the parts store all replace it with a 60 amp if you get a rebuilt. The 90's Maxima alternator is not a straight bolt-in, you have to change the ribbed belt pulley for a v-belt pulley. The mounting points are the same, the pulley isn't. It takes a little bit of ingenuity to get the v-belt located and mounted right. And you would still have to rewire for internal versus the 77's external. If you decide to go internal but want to keep the wires intact, you can run jumper wires at the connector instead of cutting. It would probably come out cleaner looking anyway.

We're getting circular here. That was my point, it "looks" like the gas impeller. Plus, why would they cast and machine the small shaft hole in the big impeller, unless they wanted to use the small shaft so they could use a small bearing and seal. The details don't make sense. No biggy, just pointing out a difference. A measurement would tell the story.

I only have my metric eye to use on the pictures, but the impeller looks bigger in ozconnection's picture, Post #22. How can you be definite?

Doesn't that look like an "in-between" pump? The impeller and its shaft are smaller diameter, but the casting, or divider, for flow control is short like the diesel pump. Referring to Post #22. Looks like a hybrid of those two.

For the record I measured on a 76 EFI system. Maybe the turbo system, with ECCS, is different. Watched your video. It kind of sounds like my car when I had the plug wires on in reverse rotation. It ran, but sounded terrible. Like yours. I notice you have an open exhaust. That can't be helping your O2 sensor signal. I don't know enough to guess at what effect a cold exposed O2 sensor would have on the signal to the ECU but it might be worth checking out. Good luck.

I would guess that your measurements are off. If your noid light fires, the ECU is doing what it's supposed to do. Put an injector on each plug and see if you can feel or hear it clicking, or use a screwdriver from injector to ear, to make sure there's enough current to actuate each injector. The engine runs. You should be able to inspect spark plugs, pull injector connections to see if a cylinder is dead, check timing, etc. You're digging in to the things that aren't really related to the problem you initially described, and getting ready to fix things that aren't broken.

Both sides are supposed to have 12 volts. It's one of the weird things about transistor control. The injectors are controlled by transistors in the ECU. They should all have 12 volts on each side. I couldn't explain the magic behind it but I just went and checked one of mine to be sure. 12 volts on each pin with key on.

Maybe your AFR reading is incorrect. Jumped on to Google and found this interesting article - http://www.mpsracing.com/instructions/Daytona/WEGO2_NB_Instructions.pdf Page 3 describes erroneous reading causes.

The noise could be just the urethane bushings more tightly mounted in the new bar transmitting differential noise. But please explain the "ripped" mustache bar. Pictures would be good.

I've been pondering a Q45 mount for my car, and I see that yours has one of the design elements that worried me. You've created a fairly long lever arm to work on the body mounting points. The nose of the diff lifts up on the end of your mount at the two diff mounting bolts, putting a much higher twisting load on the body mounting points than the long nose would. The rubber mounting doesn't add any stiffness and just lets the diff nose push up on the lever over and over. The long nose pushes directly up on the body mounts, yours pushes up on the end of the lever arm. It's probably failure by fatigue after a bunch of flexing cycles. You need to get more support over the end of the diff nose, or extend the other end of the mount so that it can't twist.

A similar thought was in the back of my mind, I thought that I had read that the 75 flange matched the Z31 flange. But I didn't think that the 280ZX (S130) turbo cars had a different flange on the R200 than the NA 280ZX's. The FSM shows a different drive shaft part number for the turbo cars, but I thought that it was for length for the FS5R90A transmission, not the flange. Another twist. Still, his post is specific to 1975 and 280ZX turbo R200s, watch out for those. Thanks for clarifying.

Just realized that you have a 1975 280Z, which has the odd flange on the R200. I think that it's the bolt size that is different and/or the pattern. Maybe that's why the 240Z drive shaft wouldn't fit your R200. Although the 280Zx shaft shouldn't fit either, unless you put the 75 tail end on it. Still weird. Nigel, thanks for the reply on the 240Z shaft issue. I hate to cause confusion but the measurements are the only way to verify what's what after they've been pulled off of the cars.

Probably will. With electronics though, it's the "and such" stuff that gets you.

They serve a purpose so it's not a bad idea. An alternator condenser would probably do the job just as well as the stock one. Or just fix the old one.

That is a capacitor, aka condenser, not a resistor. The 1978s don't use a ballast resistor.

That would be another mystery drive shaft then. I just went out and bolted my ~28 1/4" (actually 28 3/8") 1971 240Z drive shaft that gives 1.5" more room for the transmission on to a 1983 R200 and it fit perfectly, including the raised center portion in to the recess on the diff flange. Weird. I also found that mine is not 744 mm, it's 720. Edited my other post. As I said, adding to the confusion. Looks to me like the desirable short ones are 720 mm (28 3/8") tip-to-tip and give an extra 1.5" of room. Fit perfectly on an R200. The 700 mm is probably just a rough tape measure eyeball or ball-park conversion.

I have a 76 4 speed, 78 5 speed, and 80 and 83 5 speeds and they all have the fill plug on the right. The exhaust hanger ears and the speedo hold down screw are the easiest indicators and what Leon said fits all of mine. If you really want to get detailed you can measure the ratio of 5th gear, it was different for 80 versus 81-83.

Transmission, differential, half-shafts. The fuel rail will swap over and is a better design, one piece instead of three. Injectors and AAR. Exhaust manifold if the 77 has the N47 head. Intake manifold with throttle body, I think, but the ZX will have a lot of extra things on it. Distributor with ignition module.

If I had your parts, I would confirm that they were 1982, then would use the 1982 FSM, EF&EC chapter, ECCS specs. They integrated the turbo stuff in to the FSM in 1982 from what i see, so the 1981 supplement isn't necessary, and may be the wrong document for your setup.

The coil has to have current flow to make a spark. You can have 12 volts available to push the current but if the circuit isn't completed to ground the coil never energizes. Spark is made by making and breaking the circuit through the coil. That's what Megasquirt is supposed to be doing, using the signal from the CAS.

They are spendy. Some people have been bale to clean up the carbon trace and contact switch and get them back in order. Still not sure where you're getting pins 33-36 as an AFM test. By the AFM diagram, there is no pin 36 used on the 1982 turbo AFM, from what I get out of the FSM. Only 33, 26, 31 and 30. Are you using a turbo AFM or NA? They're different. And you measured different pins for your "test 2 partially open" than you did for the first test. 33 and 26 first, then 33 and 31 for "test 2". Hard to tell what you're doing. Are you using the 1982 FSM or one of the Chiltons/Haynes manuals? Page EFEC-96 has the diagram and EFEC-98 has the AFM test and specs. Looks like you might be on the right track, if you can get the right numbers in the right places.