Neumeier

You picture labeling suggests that the negative side of the coil is hard wired to ground. This does not seem correct to me. Generally, the positive side goes to the ignition (i.e. 12 V when the ignition switch is on) and the negative side connect to ground through the points. The way it works is as follows. When the points are closed there is a sudden surge of current through the primary circuit of the coil. This then induces a current in the secondary circuit of the coil (at a much much higher voltage) that provides sufficient voltage to get a spark. So, if your negative side is hard wired to ground, and not hard wired to your points, you will not get a spark. In fact, a steady current across the primary of the coil creates ABSOLUTELY NO SPARK.

I purchased a set of Sumitomo HTR H4 s recently, and they are very good. Quiet, handling is OK, H-rated, and they look good. Also good traction in the snow and ice, although being in Texas you don't have to worry about that! Can't beat the price at $45 each. http://www.onlinetires.com/products/vehicle/tires/sumitomo/195%252F70-14+sumitomo+htr+h4+90h.html

Thought I'd add a reality check. I have been driving my '78 the last four days with weather from -15 F to -5 F. The heater works just fine, so all of this stuff about the engine not developing heat because it is radiating it away does not make any sense. I'm not sure what thermostat is in my car, but it is probably around 190 F since the care has always been in Montana. Sorry I can't offer any technical input. Seems that the thermostat is at fault to me, but you have checked them in a pot of water to make sure they open - a good idea!

My '78 had the same problem. In the engine compartment on the right hand side (to the left of the battery, about half way down), are some vacuum lines entering the firewall. Check there first and work your way to the right fender. In my case, the problem was right at the firewall. While the vacuum lines under the dash can be a problem too, they tend to hold up much better.

I believe Black Dragon has a very good selection that covers the types of materials similar to original. Although I have not purchased any from them specifically, I have installed three sets of these aftermarket upholstery kits and the quality is very good, probably better than the originals.

It is probably not the throttle position switch, but could be worth checking anyway. It is used to tell the ECU one of two things: 1. It the throttle closed so that the ECU knows it should be in idle mode and 2. If the throttle is full open, to tell the ECU to provide a richened mixture. So, I don't think it would do anything when you are mid throttle, unless it had faulty contacts that were giving intermittent readings. So you could check that as well, just to be sure. Another thing to do would be to inspect all vacuum hoses for cracks and leaks. In particular, the large rubber ACM to manifold hose is VERY important. If it has cracks in it, the AFM will not sense all of the air coming into the motor. THis can cause the motor to run lean and stumble.

The procedure will be testing the resistances of the AFM across its, usually, four terminals. This amounts to just checking whether or not they fall within the spec ranges. It may not tell you whether or not it is faulty during real operation. One other thing that could be important is checking the connector to make sure the contacts are clean. As cars get older, these contact issues become more of a problem. The connector could be loose as well. It would be good to get your hands on the fuel injection service manual. I have one in pdf format for my '78, but your system is probably different. You could do a search on the web, or on this club site. Also, you might just check at a few of the local parts dealers. AFMs are a pretty standard replacement part. They might be cheaper than I think.

I think it is your air flow meter (AFM). This is one of the most important parts of the FI system, and the only one I can think of that will be affected by depressing the throttle. By measuring the amount of air entering the motor, it determines how much fuel the injectors send to the motor. If it sends faulty signals to the ECU, the car runs poorly. Basically, the air flap in the AFM is connected to a metal probe that swipes across a printed circuit board. This leads to a variable resistance that the ECU uses to determine the amount of fuel to send to the motor. The circuit board can get worn or dirty, and this has a major affect on how the car runs. The AFM also has a temperature probe, another resistor, that is used to correct for air density. Might be good to ask other members where to get an AFM. They are probably not cheap. Most parts suppliers (NAPA etc.) would sell replacements. Good Luck!

Dirty brake fluid is a bad sign. I recommend replacing the master cylinder, rear wheel cylinders, rebuilding the calipers, and replacing all rubber brake hoses. It is not so expensive if you do it yourself. Brakes are important!

First of all, you need to be sure that the brake shoes are not hitting the drum by backing off on the adjusters, if you can. After this, applying heat (lots) in the area around the wheel studs, not to the entire drum, is the way to go. You can also put some penetrating oil in this area too, and let it sit overnight. You may GENTLY tap the drum too, but don't overdue it. Sometimes just from heating they will pop right off. Upon reassembly, I put a VERY thin layer of grease on the steel flange (part where wheel studs are) so that the drum is less likely to stick in the future. I think that one reason why this contact area corrodes is that there are dissimilar metals in contact (steel for the flange and aluminum for the drum), this promotes corrosion.

Was looking at this old thread, and thought it worthwhile to add this: I have a 1978 280Z, built in January 1978. My pulley was made such that the bearing could not be removed. There were no snap rings. Apparently, at the factory the bearing was pushed in to its stop, and the metal on the installation side was compressed to retain the bearing in position. As a result, the inside diameter on that side of the bearing was significantly smaller than the outside diameter of the pulley. My bearing (also a 6302 w seals on both sides) was only squeaky, and had little play. I gently removed the seal with a miniature screwdriver cleaned the bearing well with mineral spirits, repacked the bearing, and replaced the seal. It is now quiet again. This was a bit cheaper than the $100 for a new pulley. Also, note that the pulley can be removed WITHOUT removing the entire idler assembly.

Might be the fuel pump. If you have not changed it, might be good to do anyway. Could also be that the arm of the fuel pump which rides on the camshaft is stuck.

In my 1978, I had a similar problem. At the firewall on the passenger side in the engine compartment, you will find some small vacuum hoses. On my car, one of them was split. Since these provide vacuum to make the entire heating/cooling system switch panel work, there was no heat. Seems all of the moving parts in the system are actuated by vacuum. Have a look at the hoses, I bet that is your problem. Good Luck!

You can look at this link for the panels on my '78 Z to get an idea of how the ones from another vendor look. http://www.classiczcars.com/forums/showthread.php?t=25930&highlight=door+panels&page=2

There are a few companies that make tires with some of these older sizes, if you'd like to stick with the 14" rim size and original size tires. I recently bought a very nice set of tires for my 1967 MGB made by a company called Vredestein. I think mine are the sprint classic. Here is the web site: http://www.vredestein.com/Banden_Bandgroepen.asp?UsersessionID=25427973&BandgroepID=5 These are not really anything like the performance tires of today, but they would retain the original look/ride of your car. I had to have mine shipped here from NJ. You might have a dealer in OR. John

If you leave the slave dangling, and push the pedal, the piston will pop out. Don't do that! The bleeding description you received sounds good. Have someone push and hold the pedal to the floor, open the bleed screw till fluid flows out (in a controlled manner), close the bleed screw, and tell your helper to release the pedal. Do this about 6 times, then top up the fluid reservoir. Then bleed a few more times until no air comes out. When you are finished, tighten the bleed screw and top up the reservoir. I'm not sure about the adjustment issues. My '78 280Z has an adjustment only under the dash. Once yours is properly bled, you may have to test if the clutch is releasing correctly by starting the car and giving it a try. As someone mentioned above, the pushrod at the slave cylinder does not move much. Probably less than an inch of travel is typical. Let us know how it goes!

Would you please explain to us the procedure you are using to bleed the system.

You need to check the fuel pressure. Might be a bad fuel pump. For a fuel injected car to start and run well, you need over 30 psi (check manual on exact number). It should even hold that pressure when the motor is turned off. Good Luck!

If you are replacing the slave cylinder you also need to replace or rebuild the master cylinder. Each one is subjected to similar wear. I also recommend replacing the rubber hose leading to the slave cylinder. They sometimes swell up internally, restricting fluid flow (same can happen in a brake hydraulic system). Once you have changed these parts, then you can bleed the system. My guess is that your problem will be solved since it definitely seems to be limited to the hydraulic system. The master cylinder is easy to rebuild. I believe you need to disconnect the pushrod at the top of your clutch pedal (i.e. in the passenger compartment) before you can pull the master cylinder out. Good Luck!!

Have a look at this web site: http://zhome.com/History/colors.html

Hi George, When you get a chance, email me at neumeier@physics.montana.edu so that we can arrange payment and shipment. Thanks very much for responding! John

Will do! Thanks!!

They are the same.

Does anyone know where to find this type of center cap for the factory alloy wheels on a '78 280Z? They are slightly square, unlike those on later wheels. The dealer no longer offers them, nor does Black Dragon or The Z Store. Thanks!

Generally, it is a good idea to replace the slave cylinder, master cylinder, and hose at the same time. The cylinders are very easy to rebuild as well, if you want to save a few bucks. Black Dragon has the kits for these ($13 and $7 each). Make sure you flush out the old fluid from the steel line too.