beandip

I have a ZX engine in my 240 with auto . better than double your mileage . I am running SUs though. Have you run any injector cleaner through the engine ? I would try some in the next tank full and see if this helps. You have something major going on . I will send you a PM with some info . Gary

What are you driving now ? You didn't say. The diff in the automatic will be geared at 3.54 to 1 . If you are driving a manual 4 speed you have 3.36 to 1 . The lower gear will give you a little more off the line and will lower the top end some. Many Z driver have done this for performance . It is easy to change the diff . Rebuilding the diff is not something you should attempt unless you know what you are doing. Best to take it to a shop for a rebuild. I would just install the 2 + 2 diff. Gary

76Datsun , I read through all 15 items and didn't see anything that would hurt the engine . On the over heating issue. In addition to the heater pull the hood lever and let the hood ride on the safety catch . This will allow more air flow. Turning on the heater has been used for as long as I can remember . It just adds a additional radiator and a little more coolant to the system. He didn't say to red line the engine , only to take it to 5500 . For me 5K is fine for a shift point . Because you will be at 5500 so quick that because of the lag anyway. As to the battery issue . Between my boat and travel trailer and the Z in winter , I have 5 batteries to maintain . I have always charged each battery once a month and have never had a battery go bad on me . Usually they will recharge to full capacity in about an hour each , accept for the deep cycle , they take a little longer . Never let your battery set discharged . It sure to go bad on you . Just for a maintenance item , it's a good practice to change the coolant every couple of years any way . Also bleeding the brakes at that interval will help in keeping the moisture out of the cylinders and destroying them. As for the first 3 items I don't think you can just make this statement as a cut and dried Truth. they have Merritt but there are variables such as amount of throttle applied and so on . Lugging the engine is never good . Gary:rambo:

I Don't know about the headlight buckets , but new fenders are still available from Nissan. Jim Coffey recently bought a couple . Some body here on he site must have a extra sugar scoop laying around they would part with . I am sorry to hear about the damage to your Z . I am with the others on the paint . If you are contemplating a paint job in the near future , just replace the parts . Have the car up and running and deal with the rest of the issues when you are ready . Gary:rambo:

For here in the lower 48 states, 10w30 is the best all around weight oil for winter and summer. In winter there are a few northern states where temps drop to -20 F or less , a thinner oil would be advised there. But I don't think many early Zs will be on the road in this kind of temp . Opinions on oil is like a nose , everyone has one . Ha ha . (I cleaned that up) . Gary:rambo:

I will send a PM with a email address.

One thing you could do is to change diff to a LOWER gear ratio. You have 3.54s now , 3.70s will give you more off the line but any lower than stock , will lower your top end. 3.70s are from a '79 2 + 2 ZX and is a R-200 diff. You have a R-180 I believe , so you would need the moustache bar also . The R-200 is a stronger diff. . This is about the least expensive of a mod you can do that will yield more performance. I did this in my Z and it does make a difference . Gary

This stuff was used in a effort to stop the overheating of the fuel rail. In '73 the emissions carbs , flat tops , were introduced and the percolating of the fuel in the rail became a real problem. This is also why the electric fuel pump was added. Gary

OK you love cars. Welcome to our club . What is your question ? Do you have a 240 or 280z ? Carbed or injected ? GAry LAFD retired

I am not familiar with Helix . So I have no opinion there . However I wouldn't use that wt oil 10w-30 Is a Far better choice. Gary

Welcome to the club. I am sorry but I cannot help with the Weber's . If you had the SUs that would be a different story. I am sure there is someone here that can be of help. I just wanted to welcome you to our little group . Gary

Just one thing I would like to add. What oil are you using in the carbs ? If you are using a thin oil like ATF or Marvel , this could also be the problem. I recommend 20w and if you cannot find that use 10-30 as a second choice. The thinner oil could cause the vacuum piston to flutter up and down slightly which in turn will do the same to the needles. With the engine completely warmed up to driving temp. If you were to go to wyed open throttle and let it drop , just blipping the engine . Do you ever get a back fire or pop out of the carbs ? If so you are for sure too lean . Gary

EVEN MY FLOOR PANS ARE YELLOW !! When I picked my color I had not seen another yellow Z. Other than Mike's but that was back in '01 ! What can I say . Yellow is now what Dark green Metallic was in '96 or black was . Gary

YES THE PRIEUM SET IS THE SAME AS ZEDD FINGINGS .

Give fellow member V8-240Z a shout , he is the guy that also makes the spindle pin puller , that I have to loan. He has one that lets you keep the finned cover also a simple up grade that does away with the old strap over the pumpkin. Gary

I have a driver side pan I am not using Richard. Mine are from ZeddFindings. I never saw any from Troy. Gary

Stock needles are 54s . You should be able to find them an the Nissan dealer. I found that these needles work the best in my 280 engine and also the same needles in my 240 . This surprised me in that when I changed engines and the ZX engine being larger and with a moderate cam and headers . I thought I would need richer needles. I tried several different ones and came back to the 54s for overall drive ability and performance. this is My experience any way. I tried the SM , the 42 from Nissan and they were both WAY to rich . I was getting unburned fuel in the crankcase. I am at 300 ft elevation , If you are in Co or NM you may look to the 58 needle as it is a leaner one . The only way I have found to determine the needle number after it is used . Is to mike a known needle and then mike the one in question at the precise same length for comparison. factory needles are printed with the numbers . SMs are stamped with the letters. Gary

There is allot of prep work to be done for an engine that has been setting that long. Especially in your area of the country . If you were in AZ or Ca that would be different. I bought my engine with out hearing it run and All I did was to make sure it was not locked up. Pull the plugs and shoot some oil in the cylinders put a socket on the crank pulley and see if you can rotate the engine . If she will turn over , this is about all you can tell . at least the rings are not rusted in the cylinders . If you cannot turn the engine smoothly . PASS ! Dont try to turn it over with the starter ! If you have a stuck valve you can dammage a good engine .

YES I DO ! YOU JUST NEED TO GET RID OF THE LOOSE NUT BEHIND THE STEERING WHEEL !

We used to call it dum dom . You can find it at a camper or trailer supply. They have it in a roll that is about one inch wide and maybe 10' long. It is used to seal around windows and vents when they install them on campers. It is a puddy like stuff that will not harden and is sort of like silly puddy. Just roll sum between your palms to make a thin roll about the size of a pencil or less and a foot or so long . Just stick it on the fender flange and bolt the scoop on . Use your finger to remove the excess that mushes out . This will keep the water and stuff from finding its way up from the wheel well . One thing about this stuff , you can use it to seal seams under the car and around the hoses that enter the cabin in the rear of the car from the gas tank. It doesn't shrink and stays soft enough that it will flex with the sheet metal of the car . It's a good thing to have on hand . Gary

the '79-'80 has the 12-80 and this is the module for those Zs plus if you want to run the ignition on a z with no computer and SUs . There is a way to use the 12-92 module on a carbed engine but you need to have a vacuum advance with two ports and one is connected to manifold vacuum and you must make a limiter to keep the dist from retarding the timing at speed. Gary

The vacuum advance provides about 6 or so degrees of advance for low end performance then the centrifugal advance takes over. I don't know if your '76 dist has the same type of advance ''breaker'' plate that the later ZX unit does. If so they have ball bearings that are in between two plates . This allows the plate to move when the vacuum advance functions . The ball bearings are held in place with plastic keepers. After 30 yrs of use they become brittle and crack and allow the balls to fall out , then the plate cannot move , or barely so . the engine will run sluggishly like a flat spot when you depress the gas peddle from a stop. Gary

If you turned the mixture adjustment nuts counter clockwise , or up . all the way and you are still running rich , as Colorado said, check to see if the nozzles are stuck down. Just reach under the front of the carb to where the small fuel hose connects to the adjustment and push it up with your finger. If it snaps up then the nozzle sticking in the problem. One more thing , if the float in one or both of the float bowls is set too high or has sunk to the bottom or maybe just stuck open the raw fuel will run into the intake and flooding will also happen . One last thing , if the little fuel lines that run from the float bowl to the adjustment are stiff or brittle , this will cause the nozzle to stick. DO NOT REPLACE THIS HOSE WITH VACUUM LINE OR NON GASOLINE RATED HOSE. buy THIS HOSE EITHER FROM ZTHERAPY OR NISSAN . Auto parts store hose is too stiff and will not work properly. If you have a HOBBY store in your area , ask for gasoline rated hose and not plastic. too much heat from the headers or manifold. Try a cycle shop also . We have covered about everything that will cause the rich condition. That I can think of. Gary

The mixture adjustment is turned counter clockwise to lean and clockwise to richer. To start with turn them counter clockwise to the stop and then back them back down, or clockwise 2 1/2 turns. This should get you on the right track. You then can balance the two carbs with the uni-sun to get the correct air flow between the two . With out properly balancing the two carbs you will find it impossible to set the mixture properly . Also check that the choke cables are not sticking when you turn off the choke. One more thing , you could have a nozzle sticking down when you turn off the choke . If the nozzle sticks down it will cause a vary rich mixture in that carb. Gary