beermanpete

The reaction disk is in the brake MasterVac, it is not part of the clutch system.

The damper oil will not cause the symptoms you reported. The most likely cause is bad float valves. Check the float valves for dirt and damage. Check the float height setting while you are there. Check the plugs, the rich condition could have fouled them again.

Another thing to check is the reaction disk in the MasterVac. This can fall out when the master cylinder is off and will cause a low pedal and a senstive pedal feel. Look in the FAQ section on this forum and/or the factory service manual for more info.

I rebuilt a 4-speed so I don't know how many of the parts are the same as the 5-speed. I have never been able to find any parts using the on-line look-up tools. The databases don't seem to go back far enough. You can look up the parts in the original Nissan parts catalog if you download the FAST and E-FAST programs from http://www.xenons30.com/reference.html. Once you get the part numbers any Nissan dealer will be able to get them. Most are still available. I orderd from http://www.factorynissanparts.com/partlocator/index.cfm?siteid=214081 which is a dealer in Texas. The service was good and you can actually call them if you want or need to.

I have also use drivetrain.com. They have the bearings, syncros, and some of the seals. I got the balance of the parts I needed from Nissan.

The 1970 Owner's Manual recommend 95 octane fuel but does not specify RON, MON, or other. Here in Los Angeles the octane ratings are R+M/2 and we have 87, 89, and 91 commonly available. I suspect that means that the 91 octane fuel would be required for the early Z with the E31 head.

I looked at the oil seal and the markings on it are NAK TCL 80 100 13. This appears to means the the seal is made for an 80 mm shaft, which is 3.1496 inches.

I also get 3.150" for the diameter. The distance from the flywheel mating surface to the end of the 3.150" section is 1.140". The distance to the inner seal wear line is 0.970". The distance to the outer seal wear line is 0.520". The seal is 0.5" wide.

The gasket is installed correctly. The intake manifold shares mounting hardware with the exhaust manifold. There are several studs that are common to both manifolds. These studs do not pass through a hole in either manifold, they are between a port on each. A very thick, large diameter washers spans the gap between the two manifolds and a nut is placed over the washer to tighten it down. It appears that you are missing some of this hardware, or it is not installed properly. Your fuel pump may be correct, but you should measure the fuel pressure anyhow to verify what is it. Even a fuel pump designed for use with carburetors can be intended to be used in conjunction with a pressure regulator. If the pressure at the inlet to the carb is more than 4 or 5 PSI if could force the float valve open, or at least raise the fuel level required to close it. Either way the result is the same, flooding. Since you say there is no fuel leaking on the outside of the carb then it must be leaking inside which will happen when the fuel pressure is too high, of if the float valve or float itself fails. In the case of the Holley, the power valve can also cause internal flooding, as has already been said.

It sounds like a bad ground in the back for the right tail lights and brake lights/turn signals.

Your pictures show poor sealing to the head on the bottom half of the ports. The lower mounting bolts are missing or not installed properly. There is also what looks like fuel stains on the inside of the ports. The carb is probably allowing gross amounts of fuel into the manifold and the fuel is running through the ports and leaking out at the joint with the head. Check the fuel pressure. If the car still has the original fuel pump from the fuel injection system it will have way to much pressure and force the float valves open causing a flooding condition.

The fuel leak is most likely from the carb or a fuel line. A leak in the intake manifold will show up as a vacuum leak. It sounds like you have both. Find and fix the fuel leak first as it is dangerous. The vacuum leak is annoying but won't burn the car down. Check the float bowl gaskets and the screws that hold on the bowls. Check the float valves for wear and dirt. Check the power valve diaphragm. Check the condition of all the fuel lines and the tightness of the hose clamps. Check the fuel pressure. If it is too high it will force the float valves open. It should be about 4 PSI.

The adjustment between the booster and the master could cause the brakes to drag. There needs to be free play between the two to ensure that the master cylinder pistons return all the way and open the vent holes into the reservoir. If these vent holes are closed the brake lines are sealed when you are not using the brakes. As the fluid heat up it expands and applies the brakes. When the vents are open the fluid will vent into the reservoir as it expands without building any pressure. Press the brake pedal slowly with your hand. You should be able to detect 2 distinct points when free play is taken up. Once when the push rod between the pedal and booster touches, and again when the booster push rod touches the master cylinder piston. If you cannot detect 2 distinct contact points you should verify the free play between the booster and the master by measuring the length of the push rod and the depth of the cavity it goes into. I believe the factory manual explains the procedure.

Adding a flexible section should help. Or see if you can bend the pipe a bit to get the basic alignment closer. Summit sells the flex-pipe. Here is an example: http://www.summitracing.com/parts/WLK-42216/

Flex pipe or flexible hangers should help. On our '73 240Z the whole exhasut system (appears to be OE or equivalent) is solid but hangs on flexible rubber mounts. Generic rubber hangers are available at most auto part stores.

There are 3 shafts in the transmission: The input shaft, which protrudes from the from of the transmission and connects to the clutch. The main shaft, which runs from just behind the input shaft (on the same center line) through the length of the transmission, extends out the back of the tail housing and connects to the drive shaft, and the counter shaft, which is parallel to but offset from the main shaft. There is a gear set coupling the input shaft to the counter shaft. 1st, 2nd, and 3rd each have a pair of gears. One gear from each pair is on the counter shaft and the partner for each pair is on the main shaft. When you are in 1st, 2nd, 3rd, and 5th the power goes from the input shaft to the counter shaft through a pair of gears and back to the main shaft through another pair of gears. 4th is not actually a gear per se, it is a coupling of the input shaft to the output shaft and is a 1:1 ratio. When in 4th the counter shaft and all the gears are not used. The counter shaft is made as one single piece and contains one gear each for 1st, 2nd, and 3rd. 5th has a separate counter gear that fits onto the end of the counter shaft on a spline. Each of these gears has a partner on the main shaft that free-wheel on the main shaft. When you select a particular gear the appropriate main shaft gear is locked to the main shaft by the synco hub. To change the gear ratio for 1st, 2nd, or 3rd requires changing all 3 at once due to the counter shaft being one singe part. Since the diameter of each gear on the counter shaft must match with the corresponding gear on the main shaft all 3 of the main shaft gears must be changed as well. 5th can likely be changed independently from the others as its gears separate parts, but the 2 gears for 5th must be changes as a set to keep the diameters properly matched. The early 5-speeds have the same gear ratios as the 4-speeds, the only difference being the addition of the overdrive gear (5th). Just get a 5-speed from the 77 or 78 280Z and you should have what you want. I hope this explains it clearly (and correctly).

Yes, as long as the gears for the main shaft are identical in both. If the goal is to find a source for free or cheap repair parts then it would be worth trying. If the goal is to change the gear ratios it won't work because you need to use the main shaft gear and counter gear as a set.

The counter shaft for the 5-speed is longer than the 4-speed. Even it the counter shaft from the 4-speed would fit into the 5-speed box there will not be room to instal the overdrive counter gear.

The basic rebuild pars for the Z transmissions are not difficult to find. I got the bearings, syncro rings, and a few gaskets from drivetrain.com. I was able to get the other small parts I needed from Nissan. Gears and cases might not be available, I did not need any so I did not look. The special tools necessary are : gear puller bearing separator 36mm crowfoot wrench (to torque the nut on the main shaft) snap-ring pliers hydraulic press dial indicator (if you want to measure the gear lash) Get a copy of the factory manual from http://www.xenons30.com/reference.html and review the transmission section. It shows the procedures pretty clearly and the special tools needed. We had trouble removing the counter-drive gear from the counter-shaft. The gear puller fractured the back-side edge of the gear teeth where the jaws pull on the gear. We damaged one gear so we purchased a different puller and another transmission (for parts) and ended up causing similar damage to the replacement gear as well. We put it together anyhow and it seems to be fine so far even after a few weekends at the race track.

Safety wire the nuts.

The Falken ZE912 is good. We had some and liked them. Here is a pic with 225/50-15 Falkens on VTO 15x7 +0 wheels.

From what I can tell by looking at the wiring diagrams the seatbelt/starter interlock gets a ground signal form the "L" terminal on the (external) regulator. The fuel pump relay gets a +7 volt signal from the "N" terminal from the regulator. Neither if these are available directly from the ZX alternator (with internal regulator). The "L" terminal on the ZX alt. is ground when the engine is stopped and goes to +12 when the engine is running. You should be able use this to control a relay and provide the necessary signals to the interlock and fuel pump relay. This is a popular conversion. I imaging there is a kit available that would do all this. Perhaps Motorsports (MSA) sells one?

The early 4-wire tach has a calibration trim pot in the back so you can calibrate it if needed. I do not know if the later type has this or not. I repaired and calibrated mine and it is fine as far as accuracy goes. I don't like the needle bounce however. It takes too long to settle after a shift.

I agree, your regulator is bad. You might be able to fix it. The cover comes off the regulator. If the relay contacts are not badly worn you could clean and adjust the contacts to see if it will work again. Otherwise just buy a new regulator and be done with it.

Rubber wires? Check for either a bare wire or a broken conductor inside the insulation on the wire that goes to the distributor from the coil. Perhaps it is only not shorting or only making a connection when the distributor is in a certain position. Replacing the wire is easy enough if it is bad.