Zed Head

Just saw this thread over on Hybridz. You might have a turbo AFM. The counterweight may not be missing after all. http://forums.hybridz.org/index.php/topic/108020-afm-does-this-look-right/page__pid__1010448#entry1010448

Get the box end on the nut firmly, find a spot on the body to lodge it, then stick a big screwdriver in the u-joint and turn the drivehshaft to loosen the nut. The key is to get the wrench firmly placed on the nut so that it won't slip off.

Finally took my lenses off to brighten things up.

An experiment that might tell something would be to lodge a piece of rubber or urethane or maybe even wood in between the bracket and bar to see if the clunk goes away. Just a thought. I'll let the R180 guys in now.

I get it, I missed the point. Wouldn't there be signs of rubbing on the bar and brackets if they were touching when clunking?

I think that I ran in to a similar problem. You'll find that there are certain projections on the plastic pieces that stop the rotation of the various plates at certain points. You'll probably have to put it together (and maybe take it apart again) to see how it works. If I remember right, the way the whole thing worked was that one "plane" of bearings rotated a certain amount then the other plane/set took over for more rotation. The thing that I keyed on was that the ball bearings were always sandwiched between two metal wearing surfaces. Also, don't forget, that the amount of rotation is limited in usage by the travel limits of the vacuum advance canister's rod. The most vacuum advance I've seen described is 9 degrees (18 degrees of crankshaft advance) for the Z distributors (not ZX) so it's really not much rotation movement. I felt like I had it right when I could move it that small amount repeatedly back and forth and the ball bearings rode in the same tracks, and the metal wear plates were locked in place. Best I can do, I've never seen a drawing of the breaker plate taken part. Good luck.

Clunking would be caused by looseness. Do you have any loose fits on the diff's points of contact with the body, the two mustache bar ends and the mount itself? And the two nuts and studs that bolt the cover to the bar? And did you use a snubber and keep the original mount, or a GM mount and removed the original mount? I have a self-made RT-style mount and poly bushings on the mustache bare ends and don't have any clunking beyond the lash in the diff gears. I'm using the poly GM trans. mount though so the nose of the diff can't move any farther than the urethane flexes. If you had a misalignment in your RT mount you would probably a get drive line vibration, but not necessarily a clunk. If you show a picture of your setup you might get some constructive comments.

You don't need the adapter, it's for the Multi Spark Discharge (MSD) ignition module. But the Blaster coil might not be right for your 76 ignition module and ballast resistor. You should match the resistance of the Blaster coil circuit, with or without resistor, to the resistance of the original 1976 coil with ballast resistor. Otherwise, you might have too many amps through your ignition module, or you might not be getting the benefit of the Blaster coil if you use the ballast.

Where in the process are you getting stuck? If you have the parts all laid out, there may be a simple step someone would know about. I've dis- an re-assembled a couple myself.

With the flow path blocked your temp sensor is in a dead zone. Probably not very accurate. Could delay the fans coming on.

olzed makes a good point. I wonder if a long bolt was used on the front thermostat housing hole, pushing the guide in to the chain. In it's normal/proper position the straight guide, even with its plastic, doesn't touch the chain, except for the odd deceleration event when the slack might pile up in one spot. At least the ones I've seen. Looks like your guide, sans plastic, is riding the chain all the time. I second (third?) the metal on metal making the noise.

I had a 78 and its AFM had the cutoff contacts in the AFM. Not used, but they were there. The AFM looked original to the car. I now have the 78 AFM on my 76 car. I adjusted the contacts so that they worked correctly. I would guess that there was a point in manufacturing where the old inventory ran out and the 1978 AFMs didn't have the contacts anymore. But some do. The 1978 FSM shows the pins in a drawing but labels them as "useless" or something similar. Kind of funny. Just posting for a little clarity from another perspective.

It's the difference between cylinders that is important on a cylinder pressure test. 150/158 = ~95%. That's in spec. and pretty good. 80% is the worry point according to the FSM. The volume inside the gauge can have a big effect on the pressure numbers. That's why the actual pressure reading is not too important.

There should be a sticker on the bottom side of the hood with the timing spec.

For fun, I used an inflation calculator to see today's savings in real dollars - "What cost $65 in 1984 would cost $134.61 in 2010." 6 x $134.61 = $807.66 http://www.westegg.com/inflation/infl.cgi

Testing the AFM according to the procedure in the Engine Fuel section of the FSM would be the first step. All that you need is an ohm-meter for the basic testing. When things go wrong with the EFI system it's often hard to tell which piece is actually the problem. www.xenons30.com/reference More symptoms described of what's happening will also get more suggestions. Good luck.

On second thought, where's there's a dent, there will be displaced, raised, metal. Make sure that the area around the dent doesn't have a raised edge that would wear the rocker arm and screw up your lash measurements. You're in uncharted territory. Some very careful work with a whetstone might do the trick.

It is odd that the price didn't follow inflation, for new injectors. Who knows, maybe mass production benefits of injectors in general, as more cars went fuelie, kept the price down.

Still haven't seen any evidence that you know that the clutch fork is moving and pressing on the springs on the pressure plate. You can actually see the fork and slave cylinder from the engine bay, you don't even need to jack the car up. You might be spinning your wheels (pun intended!) until you know that for sure.

The gouge on your cam looks like it's on the base circle so it won't have any pressure on it, and most likely won't cause further damage. Although, in your pictures it looks like the lash might have been tight on a few lobes. The base circles are shiny like they've had the rocker arms riding tight on them. Just a couple more observations.

The 78 N47 cylinder has exhaust liners in round exhaust ports, but otherwise is essentially identical to the N42 head,with rectangular exhaust ports, on the 76 engine. All of your 76 pieces should bolt n to the 78 engine. There are tricks to working on the valves without removing the head, involving hose or rope jammed in to the spark plug hole or compressed air to keep the valve from falling in to the cylinder. You'll need a valve spring compressor also. I've never done it but apparently it's not super difficult. Are you sure it was the keepers and retainer that you found or was it the lash pad? Without the keepers I believe that the valve would fall in to the cylinder unless it was jammed closed from bending or binding.

It does sound a little bit like an alternator going bad. Or, if you have AC, check the idler pulley. You can start and run the engine for a short while with the belts removed to see if it's a noise from something belt-driven. With the alternator belt off the water pump won't be turning so don't overdo it.

Min came out of either 76 or 78 cars. They have the same number as yours, that cover looks like a typical 76-78 AFM cover number, maybe even 75. I assume that it's possible that someone removed the counter weight, maybe with some misguided idea that it would increase throttle response. Or maybe it just fell off and they ran it anyway. It's main purpose is as a damper for pulses on the vane, if I remember right. Or they took the cover off of the 1978 model and stuck it on a different AFM. The design is a Bosch design and common, you'll see them on BMWs, Audis, Volvos, Alfa Romeos, etc. No idea what you should now. If you could borrow an intact AFM, that might tell you something.

I am pretty sure, based on what I've seen, that the specs are the same as the licensed Nissan injectors. The real question (for me anyway) is if Bosch quality is better than Nissan quality. You can get the Bosch 0280150116 injector from these guys for ~$70 each - http://www.fuelinjector.citymaker.com/catalog/item/7638068/9161583.htm $420 total

Looks like someone has done more than the usual messing around with your AFM, not right for 1978. Looks like your counterweight is completely missing. Was there a number on the cover? Maybe someone installed a ZX or even a BMW, or other brand AFM. Maybe it came with the Bosch injector. You might have the balance right from your calibration, but the potentiometer trace or aerodynamics of the air flow path might be totally wrong for the engine. You have a new puzzle piece. Here's a link to the atlanticz site, probably Blue's work, for a comparison picture - http://atlanticz.ca/zclub/techtips/afm/index.html All of mine (4 so far) have looked like the atlanticz pictures. The injectors look correct for a 280Z, one's a Bosch (the same number that I have on mine, that I've seen on several local Z cars in the salvage yard, no confirmation on the cross-reference though), the other is a stock Nissan or their supplier (I think that's tan color under the black grime).