Zedyone_kenobi

Found my issue with a car that would not rev.. let me describe the symptoms, and maybe this solution will help others. My car no matter how smoothly or harshly I hit the throttle it would rev to about 4500-5500 and start to miss and sputter. Acceleration would stop entirely and the car would sputter around and the tach needle would oscillate up and down. Very disturbing. I thought it was timing at first so I adjusted that. I still may need to pull the distributor to see if the mechanical advance is gunked up. That was some good advice form a friend on these boards. I have not yet done that, but I did manage to find a spare distributor in my parts bin that came with my car. It was in used but very solid condition. Shaft was smooth and while it was gunked up in side, it had no shaft play, so this may be a good candidate for rebuild/cleaning. But I digress. The spare distributor had a new cap and rotor on it. I have long suspected the rotor was an issue. It was only worn on the edge of one side. So I quickly put it on and swapped out caps. My new cap had the benefit of brass terminals, which is far better than the traditional aluminum. Here is the rotor that came off the car. You can see that one side is visibly more 'chewed up' than the other. In real life its far more pronounced, here is a better view, Here is the rotor that went with it: Once I installed these and hooked it back up, I was amazed at the difference it made. The car was smooth at 3k, 4k, 5k, and 6k. I did not rev it much past that and hold it, but it pulled once form 1st clean to 6500 rpm with NO fuss, mess or issues. I still think there is some timing work in there, but my gosh, it runs so smoothly. I should have done this swap earlier. I installed a new vacuum advance, reset the timing, adjusted the valves, and all along it was the cap and rotor. Guess it had reached the end of its serviceable life. If that gap grows too big, no amount of spark will get it to rev. 240ZED is a revving machine now.

wow, looks fantastic! I really love the cars in this state. To see one come back from this would be astonishing and fun to watch!

^^^^ what he said!^^^^ by the way WELCOME to the sight? Have any pictures of your baby?

There is a great website with bulletproof step by step pictures and explanations on how to adjust valves. If you do a search on this website you can find it.. lets see.. http://www.picturetrail.com/sfx/album/view/1803105 That should be of some use mikewags!

I hate to admit it, but your words ring true. Actually I dont hate to admit it, but now it leaves me with more head scratching to do. I am going to keep the R180 I have on order coming and use it for comparison. I may even get it professionally rebuilt so I have a known good part. That is one job, I do not wish to tackle by myself. Just note for clarification, I do not feel slop when I turn my halfshafts. I feel slop when I push on them radially, as in up toward the bottom of the car.

Hey peace buddy, I agree. Every system can be improved, but the stock system has been working on my car for 37 years. Something to be said for that. If you want better cooling get a larger radiator, cheap, easy install, and dead reliable. Again, with a engine rebuild, you cannot stress enough protection or reliability. Also, with your electric system, should you decide to go that route. It has its own set of problems. It has a constant draw from the battery, and does put a stress on the electrical system. Older 240's charging systems to not like too many more amps than stock. So be mindful that you may want to upgrade to a later model alternator (60amp maybe). If for whatever reason you lose power to the pump, your stranded. A mechanical pump is fairly reliable, and was designed to go there. In the end its your decision, but if it were my money, I would spend it elsewhere.

I know you were poking fun, but I was pointing out that your decimal is in the wrong place in the mm part of the equation. I think sometimes threads do not convey good messages!

I totally agree with you on the timing. I pulled off the pertronix unit and hit a wall, where I got a little nervous as to how to continue. So I stopped. However with what you mention in mind, will pull her out and see how she looks all the way down to the distributor chassis. Need to find a how too guide to tearing down a distributor. Time to use the search button again. As for the diff, I have checked the usual suspects. Front diff mount is good, mustache bar bushings appear in good shape, drive shaft bolts are tight, ujoints show no slop. The stub axles are an issue. If I grab the axle on either side of the diff and push on it in the radial direction (normal to the central axis of the axle) It moves enough to feel and hear. I am pretty sure this is bad. Also if go from 1st to reverse, no matter how slowly I let off the gas, it had a definite thud to it. Now once underway, the diff is quite as a mouse. It does not whine or make a fuss of any kind. I certainly hope that I do not replace this one with a diff that is worse than mine!

keep in mind that it may be better to bring the entire short block to the machine shop so they can degree in the cam. It makes a huge difference to how effective your cam will be. I think you have your head on straight about just going Stage II and making a fun daily driver. You will be very happy with that set up!

actually, 0.012in = 0.3048mm again be careful!

I do not know how the 73's compare to the 71's, but I used 0.10 Intake / 0.012 exhaust on my stock L24 (1971). If my valves were that lose I would have lots of noise as well. But again, I have a 71.

update. Valve adjustment has been complete on the engine and all valves needed a couple of thousands adjustment. Some were out several thousandths. The whole valve train is noticeable quieter. Cant speak of performance yet as I have not driven it yet. But thats coming as soon as this weather clears up. Ordered my Diff from Zbarn.com. Very nice talking to the guys there. After the diff is swapped out, I will turn my attention to some minor wiring fixes. I will also try to do a more thorough cleaning of the engine bay. Car is nearing mechanical happiness, so I am almost ready to spend many days cruising it around. It just goes to show you that no matter how good of condition your 37 year old car is, its still a 37 year old car!

Things like electric water pumps should not be relied on for HP increases. Your talking about minute HP that people chasing thousands of a second may do. I would wager this is not you. Never underestimate the quality of stock Datsun parts. Shiny parts in a catalog look good on paper, but seldom live up to the hype in actual returns. Use stock when you can, focus your efforts on parts that will make it run strongly and reliably. Build your engine for the driving you do every day. Trying to live day to day with a high strung motor that is only happy at 6k+ every day is not money well spent. Sacrifice some of that peak HP for strong daily reliability. This is of course unless your building a drag car. Then ignore my post entirely.

Well 3-4 k might be enough depending on his goals for the car. Perhaps he does not need larger valves if all he wants is a fun street car. With the cost of head work not trivial, perhaps you can use money else where to suit your needs. Again, it comes down to what your goals for the car are.

just wanted to thank everybody for their insight and opinions. I have decided to order a spare R180 from Roger at Zbarn. He picked up the phone and was helpful with my purchase. I am looking forward to installing my new diff when it comes in. Job looks tedious, but not hard.

I have left well enough alone for long enough. This happens to all car forums who are 99% dominated by men. One girl posts anything and she gets the spot light regardless of how meaningless the content actually is. She had a real problem, the gentlemen and ladies on this forum helped her out. That should have been the end, but now the leg-humpers come out and are in full force talking about boobs, and other non Z related things. Any 16 year old is more than willing to soak it up. I am pleased her Z is out of trouble, really I am. But the rest of this thread content is 404 not found. (HA, hows that for some modern techy lingo, my inner nerd came out) It should really be locked, OR, I could just keep my nose out of it. Which would have worked just as well I suppose.

good luck with your Z. Usually HOA are more bark than bite.

Okay perhaps the lazy comment as a bit overboard, but my personal goal to stand against and end txt lingo is never going to end. As far as I know there are no letter limits on posts, so use all the keys. In my mind every time we allow txt speak to exist it becomes one small step toward it being publicly acceptable, and it should never be. But having said that, for the sake of this board, which I truly enjoy and have learned so much from, I will not dive into pointless arguments if I can help it. Its a remnant of my past board experiences I suppose. I am far from a grammar nazi, Lord knows I have a hard enough time spelling things. But, txt speak is not bad grammar, its a testament to laziness that is irritating to read. LIKE WRITING IN ALL CAPS. Not hard to understand, nor confusing, just irritating. But this is me getting off my soapbox.

Riiiiiiiight. I will remember that. :stupid: So, its not that you do not know how to spell, your just lazy. Contrary to what you believe, the teenagers of today wont make any more of a splash on society than the teenagers of yesterday. Eventually you all outgrow your overgrown sense of self worth. Its part of growing up. Okay, enough bashing, but sorry, text lingo irritates me. So do cocky kids. Man I am starting to sound like my dad... DRAT, I need to go buy something I do not need and cannot afford.

you stud you.

I think any new Z will have to go back to what Mr K thought the Z should be. A Japanese sports car for the Americans. IT has to fit Americans and be sporty enough to survive on our roads. It should be capable of winning races out of the box and should be affordable. It does not have to be the fastest car in the world, but it should have miata levels of fun built into it. Most of all, it must be reliable. The Z was known for melding all the current technology together in a way that was fun to drive and seemless to the driver. My recipe for a modern 240Z would be the following: RWD of course 4 wheel disks with 4 channel ABS 6 speed manual gearbox (No DSG or CVT here) It needs a 6 cylinder for sure, but a straight 6 is not going to happen, as nissan does not have one available to my knowledge. They do have a 2.5 liter 4 banger, that makes like 175 HP/180 ft lbs torque. That would do nicely if you can throw some Direct Injection on it and perhaps some of that variable valve timing. Make it rev to 6.5k to 7k, and let it have around 200 HP when all said and done. Its enough to make it crazy fun and not step on the 370Z's toes. It will also give room for growth in the future. This small engine will also provide good fuel economy and reliability. Plus nissan already has it. The car should be a 2+2, which I know makes people cringe, but you cannot market a pure two seater with much success thats not a convertible. I would give it rear suicide doors ala RX8. If Mazda can do it then Nissan can do it with the 250Z. This car should be a shining example of nissans new approach to building light weight cars. Make this car come in at 2700 lbs MAX, with the use of composites and Carbon Fiber its perfectly possible. Make it a drivers car. No power seats, no power sunroof, Make the drivers position and comfort pinnacle. It should have 17" rims, that are 7" wide. Any more its snappiness or steering feel may suffer. You want a stock tire size to be competitive in its class, and yet not too expensive that people will not be able to afford to replace. I would not have a turbo option, as it will become drift car fodder and it will be a poster car for the NOPI crowd, which is not the demographic I would want. The car should come in the mid to high 20's. The Nismo 250Z will may nip 30.

I have to ask how wise it is to tell somebody you don't know how to hotwire a Z. Especially somebody who can't spell or use proper grammar. Playing devils advocate, you may have just told somebody how to steal a Z.

Thanks, he has offered to sell me a diff at what I think is a VERY reasonable price. I may purchase it today, as its pretty hard to find people/vendors with such high praise.

This is good stuff. I am running the Bosch coil which I believe is sold through MSA or black dragon (or both, I don't know where I saw that). I have no idea if its a 1.5 ohm coil or a 3 ohm coil. I suppose I could disconnect everything and measure the resistance through the coil easy enough, that would tell me something. Okay, I have lots to work with here, I will check a few things out when I get home. I do most certainly have a resistor hooked up to one of the terminals on the coil, but I need to figure out what size. Its very simple. Is a wire from my coil to a resistor. It does not go anywhere else. I may need to snap a picture. More to follow.

is that the resistor connected to my coil? NOt sure Still its not a nagging concern to be honest. Car runs great. I don't often find myself revving it that hard, its just nice to know its operating correctly within spec.