visionary

I have been using a Volvo filter on my '72 roundtops, which fit directly to the carb via bolts I got at the local hardware store. They work well but are paper filters and don't last that long at $28 for a set. These are about 3 or 4 inches deep and allow decent air flow but I think I would do better with a foam type filter because I have to keep my jets leaned out (1/2 to 3/4 turn) or I blow alot of black smoke. Does anyone out there run individual foam filters and if so what type are they? Who supplies them? Keith

I need to replace my seats and because I drive the car for distances, as there is no direct route to or from Idaho, I want to put something more comfortable with more support. I also would like to find a replacement out of a junk yard because of the cost. Any ideas or recommendations??? Keith

Over the last 10 months I have driven my '73 back and forth to Denver from Boise five times (900 miles each way) and had some problems with the charging system. A couple of things happened that might help you. On one trip the alternator diodes welded together causing the system to overcharge and boil my battery. I had the alternator rebuilt by the best electrical shop I could find in Denver and it has been no problem since ($100). It gives a positive reading of about 5 amps normally now. The ramifications were that I had to replace the battery, the VR and rewire at the harness because it damaged the connector and burned up wiring. So, check all of those areas as they are vulnerable to damage when overcharging occurs. On a return trip, somewhere in Wyoming, I started to get needle bounce on the meter and pulled over to look the system over. What I found was a wire at the harness connector had vibrated loose and had an intermitent connection and signal. After securing the wire it eliminated the "bounce". Good Luck Keith

If anyone has the answer to this question, I want to know. I bought my replacement stripping from motorsport and replaced all of the driver door rubber at the same time, i.e. body weatherstrip, underdoor weatherstrip, top front of door weatherstrip, inside door felt, window frame runner felt, etc.. The labels on the rubber was from Nissan, so they were all factory seals. I also bought the passenger doors rubber as well but haven't installed it yet because of these problematic issues. My driver door still does not close properly, after a full year. I have tried all of these adjustment tricks but have not been able to get the door to close so that the body and door align. The weatherstrip on the body keeps coming loose at the curve where the door and window assembly meet also. Has anyone tried cutting the weatherstrip to reduce the physical thickness of it and if so where did you make the cut?

I have a '73 which did have the flattops on it. Those carbs now reside in my shed as I don't have a boat. It is worth a try to tune the flattops while you save the money to but a replacement carb setup. Both the Haynes and Clymer manuals have tuning instructions and you can get rebuild kits for them at import parts suppliers. You should plan on replacing them however. I got a set of '72 round tops, which is the Hitachi HJG46W, from Scott at ZTherapy and have been extremely happy with them. I had a set of cores to send him and got away with about a $400 investment. The cost will depend on what he has available for you, but make no mistake about his rebuilds, they are the best you will find in the U.S.. He replaces the throtle linkage bushings with roller bearing and makes some other adjustments and mods that improve performance. The only caution is if you plan on SCCA racing, they will not pass tech, because of the mods. Check out his website and give him a call. When I got mine from him, he was in Mt. Home Idaho stationed at the airbase. He is very easy to deal with. Keith

If your oil psi is 30-45 then you have plenty of oil pressure in the engine. The oiler tube coming off will affect the cam lobes and possibly the rockers, valves and guides in the head. I have a '73 and have had problems with my oiler as well, however it was the front tube extention that has disconnected on mine. What I initially did was to have it brazed back to the cam journal mount but found that the braze didn't hold or seal well. I thought I would try some JP Weld instead and that has worked very well. You MUST remove the oiler from the cam journals first and thoroughly clean the entire oiler first. Then be very careful that you align the oiling holes correctly so they actually spill onto the cam lobes and don't allow the epoxy to clog an oiling hole. Mine were also clogged and I had to redrill the holes. If you do this be sure to rinse any metallic shavings that you may create before reintalling. My oiler looked like it had been made by a drunk production tech who was late for his tee time. As far as the nonspecific knock coming from your engine. First, run some octaine boost, the best you can buy, then do a compression check on all cyclinders next and drain your oil and strain it to look for and metal or metalic shavings. Then report back to the forum for interpretation of the numbers.

I have an interesting problem I can't seem to solve. Several weeks ago, I checked my timing and as usual check the spark on all the plug wires. The #3 and #4 cylinders were misfiring. I quickly purchased another set of blue thunder wires and rechecked. No difference. I then checked the timing spocket on the cam to see if the chain had streched and decided to adjust the spocket ot hole #2.. After adjusting the spocket I noticed that there was no chain guide bolted to the front of the block. That combined with an oil leak from the main seal convinced me that I should go ahead and pull the front cover and replace the chain, tensioner, guides, main seal, distributor and install a turbo oil pump. To make a long story short, #3 still misfires. Any suggestions? Keith

Gary, I know this sounds stupid but did you check the filiments in the bulbs???

Sundance, I have an areo kit on my '73. It includes the front dam, side skirts and rear valance. I bought my kit from motorpsort in Orange, Ca. All of the products I have gotten from them are good to excelent quality. The glass on mine is very thick and has withstood several unavoidable road hazards with only minor chips. I am considering front fenders as well and have gotten good reports on the fenders motorsports carries. Give them a call. Keith

Thanks for the info, I was going to replace the balancer with a non-a/c type, but I think I will wait until I can find out how they are balanced. If I can remove the extra pulley on my current balancer I will, logically there would be no need to re-balance the pulley.

My '73 had air conditioning sometime in it's previous life. By the time I took ownership most the condenser was gone, so I removed the rest of the components. My question is, can I replace the harmonic balancer/pully to a non-a/c type without having it balanced on the crankshft. In other words, are the balancer's internally or externally balanced. It is a rebuilt L-24.

Hey Timberwolf, I have been agonizing about tire sizes and profiles for my next set. Currently, I have 195x14" on 14"x6" rims. I like the goodrich radial TA and I think I will take your advice and stay with the 14" rim but do not know what the width limitations and/or optimal setup is. Any advice on rim width? Keith

This is a request for information concerning the removal of the intake manifold thermostatic value and abatement of the coolant flow through the intake manafold. I have disconected and discarded, for the most part, the emmisions systems connected to the fuel system. I was looking for tesitimonials on the removal of the thermostatic value and coolant flow through the intake manafold. My concern is low temperaature operation during the winter months connected with living in the northwest. Purportedly, the value is supposed to maintain a constant 150 degree temperature of the coolant through the manifold, however, I have noticed power loss at higher engine temperature operation and tend to regard this system as suspect in the optimal mixture flow at higher temperature operation. Any opinions or tesitmonials welcome... Keith

I was just shopping at http://web.ctsolutions.com/zeddfind and he has a '73 gas tank for $50. check it out

I believe that the tanks on the '70-'78 models are virtually the same. There are several issues you need to address when replacing or reconditioning the fuel tank. Mike has excellant advice in the fuel system BB section that you would be wise to consider. Also the hoses and connections to the fuel tank assembly are all critical elements of proper fuel delivery in these cars. One leaky or worn connection or hose can impair that critical performance function. I have replaced all of my hoses and connecting apparatus with great success in reducing gas fumes and consistent fuel pressure. The hoses will cost about $150 U.S.. Don't forget that on the '73 the fuel system is "presurized" and even an improperly sealing cap can cause disruption in proper fuel delivery and pressure under 'normal' operating conditions. Good Luck P.S. The '73 has the "late model" evaporative emmission control system. I have modified mine with great success as well, don't forget that it is a 'closed system'. visionary

I have a '73 with no smog, 72 SU's, stock intake and exhaust('72 manafolds) and I get between 18 and 22 combined depending on my mood and the density of traffic. I have gotten as little as 16 and I always use premium gas. I have also changed distributors to a single point and removed all advance retard switching units, thermo couplings and wiring for the auto(rebuilt) transmission with impressive performance enhancments. Will need to rotate tires soon...

If your SU's are to rich, it will be evident on the spark plugs(they will be black). It is very easy to check obliviously and is some I do whenever I go to adjust my carbs first. You may have 'leaky' throttle bodies on your carbs. Were the carbs rebuilt by a competant expert befor you installed or were they only given a "kit" rebuild? The problem is that after 27 years of wear on the linkage that connects and syncrenizes the carbs the bushing wear out causing air to leak into the carb body though the linkage. The only thing you can do to remedy the situation is to rplace these bushings. Scott at Z Therapy has rebuilt thottle bodies at an affordable price after you send back your cores. There is aproblem with his rebuild if you plan to race your Z however. His rebuild is excellant, but not within SCCA rules... Also, do not run different neddles or you will never actually synch your carbs mixture. Good Luck...

I made the conversion you are asking about. I don't know about the roadster question because I do not know what SU's are on that car. The correct SU carb is the Hitachi HJG46W. Mine came off of a '72z but had leaky thottle bodies. I remidied the situation by calling Scott at Z Therapy and getting a reworked set from him with a rebuild kit for the remaining parts and pieces. Discard the intake manafold as well or attach it to your boat for an anchor. I have cannabalized some of the manafold 'plugs' and fitting from the flattop setup but that all. While adjusting my emmision control systems a bright flash of light initiated a consise eurika moment and I trashed the enitre system as well, with substantial increased performance and cooler high RPM operation. Good luck. Talk with Scott, he is very knowledgable about these mods although he will always try and sell you the "shiney" ones.

Jason, Have no fear, your toubles have only just begun. I have a '73 240z. It was manufactured in 11/72. The wiring in the car is the "late model S30 series USA". You can abtain a copy of the wiring diagram for this series in most aftermarket repair manuals. If you go to purchase a manual, I would recommend the "Haynes" manuals over the "Chilton" manuals. Moving on... The first thing you need to do is to identify any modifications in wiring, especially deviations of the factory connectors from your ignition switch on the steering column to the main wiring harness that passes though the firewall. Hopefully, all the factory switching and connertors are stock. If they are not, consult an expert to sort out the wiring, unless you are an Ohmeter guru. Lets talk about the ingition wiring first. There is a common point of confusion where the ignition wiring meets the coil and resistor. It is well founded confusion.There are two black with a white strip wires that come out of the harness where the resistor and coil are mounted on the inside fender wall. The Nipon masters of identification decided to put a sheath on one of the wires, I have always assumed for identification purposes. I could be wrong. Hopefully, that black sheath is still on the wire in your care because that is the black with white striped wire that goes to the resistor. It is connected directly to your ignition switch. The other black with white striped wire goes to the positive terminal on the ignition coil. That wire is connected to your tachometer. If you do not have a sheath, use a continuity check with an ohmeter to distinquish the correct wires. The other terminal on your resistor should have a green with a white stripe wire that comes directly from you ignition switch and has a junction that goie to the tach. Now, if your battery is charged, your starter is correctly connect(which does have a fusable link)and your voltage regulator is properly functionng and there are no wiring discrepencies in that system you should have spark from your coil wire that connects to the distributor. One more thing. The black/white wire from the ignition that goes directly to the resistor has a junction that proceeds to the fuse box on the console. It takes a 20 amp fuse. If you do not have spark, check the integrity of wires with an ohmeter and check your battery, starter, voltage regulator system. Basic common sense will follow the spark... Good luck and let us know... visionary

Hey bambikiller, Thanks for the squeak tip, kind of reminds me of a girl I used to know. Have you ever seen that short animated film, "Bambi meets Godzilla". Check it out, its a laugh. Keith

Hey bambikiller, Thanks for the squeak tip, kind of reminds mi of a girl I used to know. Have you ever seen that short animated film, "Bambe meets Godzilla". Check it out, its a laugh. Keith

I am planning to replace my soft rubber mushtache bar bushings with urathane bushings I purchased from Motorsport. I have heard some frightening rumors that the old soft rubber bushings have to be heated to be removed completely. Has anyone else heard of this tecnique and, if so, will a propane torch do the job or is and acetaline torch part of the therapy? After some close negotiation with my exhaust system, differential and the lug nuts the local brake shop tightened to tight, I was able to remove the mushtache bar from the car. Upon inspection of the very worn and decaying bushings I thought I would call one of our reputable machine shops and have the original bushings pressed out of the bar. After finding a machinist that was willing to run his press on Friday afternoon the conversation ventured into the specifics of the job. My knowledge of machine shop nomenclature being minimal I tried to explain the type and construction of the bushing and differential rear mounting bar to him and was assured that next week he would give it a try. Although handle bar moustaches are not that uncommon in this part of the USA the concept and my intent did not communicate very well. So, I pulled out my propane torch, clamped the bar in my workmate and started to burn. This technique worked very well. It took about ten minutes on each side to completly eliminate all of the old rubber. After this I cooled the bar with warm water and used a half round file to smooth the inside of the bushing housing. After a bath in solvent the new urathane bushings were very easy to gently tap in with a rubber mallet. Yippie-i-o-tyee from somewhere in Idaho [This message has been edited by visionary (edited 06-23-2000).]

I recently purchase a '73 240z in Denver, Colorado. The car had been stored for the last five or so years with apporimatly two months of driving time over that period. On my return trip to Boise, Idaho, the transmission (automatic) began slippping out of gear. I had the transmission rebuilt, replaced the flexplate, torque converter, and installed a new starter as the old starter was damaging the teeth on the flexplate. While driving the car to break in the reubuilt transmission, I ran out of gas. After putting fuel in the tank, the car would run for a few miles and then stall. I replaced the electronic fuel pump, both inline filters, and blew out the main fuel line. Prior to bringing the car back from Colorado, I had replaced the SU's with refurbished throttle bodies from Z-therapy as well as a complete rebuild on the carbs, which seemed to work well. The car is delivering fuel to the engine well now, however, I have no spark from the coil. I have replaced the old coil with a high output Accel, replaced the points and condenser with out success. If anyone has any ideas I would appreciate a note. At his point I am a little stumped... Thanks Keith Short 10 June 2000 An update: After checking the wiring diagrams, and using my trusty Ohmmeter, I became supect of the resister module. The meter gave a 1.5 ohm reading, however, I suspected that the module was failing at load. I replaced the module and the spark returned. Hope this helps others in this situation... Keith [This message has been edited by visionary (edited 06-10-2000).]

Jon, I am experiencing the same problem. I just had my automatic transmission rebuilt and while putting a couple of hundred miles on the rebuild, I ran out of gas, OOPS. Anyway, after replacing the filters and electronic fuel pump, I tried to restart my 73 240z to no avail. I checked for spark and found I did not have any from the coil to the distributor. I replaced the coil with an high output Accel, replaced the points and condenser, once again, with no success. The distributor is a '73 single point. If you have any suggestion, PLEASE let me know... Thanks, Keith Short