visionary

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