datsky

The 5sp tranny start at the 77's? I thought they come-in in the 75. I have no idea has my tranny ever work properly before. I picked up my z not too long age, and this car is parked since 92. Dramatically this car got impounded at 99 and lien sale to 2nd owner at Lancaster and then lien sale to 3rd owner in Los Angeles in 2010 then lien sale to me at 2011. yea. That was the whole story. I have no idea what the previous owner had done to this car. However, it went back on road now. The tranny is the only thing makes me crazy at this point. I cant go long distance with my Z. If I cant figure out the problem, I just simply change the clutch and all the bearings. If the issue still, I JUST SELL IT AND GET ANOTHER ONE.( the another one means tranny. not the whole car. lol ) Sorry Jasper. At this point I just have no idea what other info I known from this car. . :/

The reason I replaced the Clutch Master cylinder and slave cylinder was this problem. I thought it was all caused by the worn out Master cylinder or slave cylinder. After I have them replaced, the problem remained. Things I have changed: master cylinder, clutch cylinder. hydrolic hose, and tranny fluid.

Thank Jasper. My car is 75 280Z 2+2 5sp. Production date is Jan/1975. I wonder if anywhere I can find the model of the transmission? Or where to locate it? I don't think there is any mod have done to the car yet since this car been parked since 1992. Anyway, everywhere I check is original. The slave is identically the same as the one I taken out off the car. The pedal push rod is adjusted with little of free play. To ensure I will have clutch, I adjust the clutch pedal higher so I dont have to push the pedal all the way to the floor to disengage the clutch. A friend of mine gave me a new master cylinder to me. it looks very clean. and he said it have no problem.

When is gets hot. It feels like the fork is not pushing the throw out bearing far enough to disengage the pressure plate. However, I have a buddy push the clutch pedal for me and I watch how far the slave cylinder push. The result is the same distance. I assume there is no air in the system.

When tranny gets hot, it is very difficult to put into any gear. Yes, it will grind when putting in reverse. If I shut the engine, there will be no problem to shift into any gears even it is hot.

thanks for your reply. After the tranny get hot, it is difficult to shift in all gears, included reverse. To put in gear, I need to pump the clutch pedal many many time until it get in gear. After it gets in gear(without driving it), it dont want to pop out of gear again. I will have to pull the shifter very hard to get it out or gear. After it got out of gear, it dont want to go back in. However. if the car is moving. there will be no problem for putting in any gear. wired..

Hope it just wrong type of oil is being used. I drain out about 1 quart of oil oil(the shop claim is 75w-90) and refill with 85-120 gear oil. However. Not too much of improvement. GL-4? Do autozone or pepboys have them for sell? thx

Thanks for your reply. Sorry I have no idea what dragging clutch is. What do it do when clutch drag? For my think, Would it be the pilot bushing expend after it get hot? It seems less likely going to happen. no?

So the gear box out time huh? but it shifts very smooth and clean when I start the car in the morning. I means it just work as good as new tranny. I don't see any leakage from hydrolic system. . . I have very little knowledge about tranny...

Thank you for your replies. I have changed the clutch MC and slave cylinder brand new already. The funny ( it is actually not funny at all ) thing was this problem only appear when the car is hot. What I meant was you can feel the shifter is hot like kind of hot. Then it will start to have difficulty to shift in gear. I think I will need a new clutch throw out bearing? clutch plate? or heavier weight of gear oil?? thanks

Hello all I have my transmission fluid changed a month ago with 75w-90 gear oil. New clutch master cylinder. New clutch slave cylinder and hose. The system is bleed more than 3 times. I bleed the system with proper way. In the morning, the transmission shift very smooth and easy. however, after about more than 20mins of local driving, it start to getting hard to put in gear. The pedal has good pressure, but seems the clutch is NOT getting disengaged even the pedal is on the floor. or say this way. it cant put in 1st gear even the pedal is on the floor. In order to put in gear, I may have to pump the pedal continuously to put the gear in with great effort. After the gear is in(while I'm still holding the pedal), it is very hard to pull the shifter out of gear(feels as same as pulling out of gear without pedal). All these only happen on stop-and-go situation. After the 1st gear, it shift a little better or no problem. Once the car stopped, it happen again. If I parked the car for a while til it get cold, It shift smooth again. This only happen when the car is worm up. Some people suggest is the throw out bearing got stock because they will expend after it gets hot. Have anyone experienced such situation? I don't want to changed the clutch and throw out bearing and the issue remained... any input is appreciated. thanks all

$400 is affortable and sounds good. However. I really would like to put a flat top piston into my Z. Finally I got my 75 2+2 running after been sitting in the garage for almost 20 yrs. Spent like almost 1k to bring it back to the street. At this point, I would just leave it as is since my wallet is on E now. lol It is still good to collect all these infos. Whenever I got my wallet filled up, I know what to do. My aim is to get 160-180whp for daily driving with affortable price. Thank all of you guys' info.

THank you very much for the Info. Upgrade spring sounds sweet for what it can do. Spring + valve seat + cam all together are good enough for street tune for me. Since I'm not aiming for track, I'm more looking toward street comfort driving. At least, when I enter the freeway, I don't have to worry about the back coming car will bump into my rear end. lol. All I need is 20HP added to OEM power. 460" lift cam + OEM spring + valve seat + flat piston are all I need. will this work? Thanks for all of your advises. Have a good day

I been thinking about to put a stock ZX flat piston into my N42 block with Isky grind cam. Since I have never done this before, I wonder what is the best cam profile for the flat top piston? My main concern is the valve will be push too far and contact with the piston. will .500 life & 260 duration too much for flat top piston? thanks for advise.

I didn't know why I didn't take the whole engine. However, I broke the head stud while I was taking off the head. lol. I already have a N42 block installed in my Z, so all I need just a head.

Thanks

Thank you very much Tony. The N42 head is purchased from the Pick-A-Part. There is no way I can match the numbers up. Since I have it as a spare, I would just better off to send it in for cleaning. Maybe at the same time send the cam for grinding. Is there any good shop for head job? Valve seat would be nice, and do it once for all. I have never done any head work before. At this point, I dont what kind of precaution need to be taken. Thank you very much

Hi guys. Recently I picked up a N42 head from a 75 EFI 280Z at pick-a-part. The head looks good. What happen was, when I pulled the head out of the block, I found the block has flat top piston. From what I heard, the N42 block is originally come with dish piston. Since the block has flat top piston, it may be a good chance the N42 head I picked up has performance cam. I do want to upgrade my cam shaft. If the cam shaft from the N42 head is already a performance cam shaft, all I need is to install flat top piston into my block. Is there anyway to find out the profile of the cam shaft with out sending it to the shop? If this doesnt work, I may just buy or regrind my current cam shaft. I heard Isky cam is very good. Have anyone have experienced it? I also have found Webcam near local. They seems pretty good too. http://www.webcamshafts.com/index_blank.html?pages/cam_glossary.html please help me out on this. any input will be highly appreciated.

The car is running stock EFI. May it be the bad injector? The injectors are spread as jet instead of mist? Injectors are not cheap. Arh...

Thank you for your advise. I dont have the wideband O2. All i have now is the adjustable meter fuel regulator. I adjust it to regulate fuel at about 52 PSI and retard the spark timing. It idle at 1K RPM and now idle at 500RPM. Some what i still hear a very little of the knock. It knock when I let go the throttle from about 3K RPM or more. I read the Datsun Z EFI system, and noticed that the fuel injector will complete shut off at deceleration from 3k RPM or above. That is when the knock start to be heard. Since the throttle is shut, the injectors will operate at idle speed. However. the engine RPM is not at idle yet (lets say it is coming down from 3K RPM). I wonder if enriching the idle fuel mixture will cure the knock? and how? Some people suggest it would be a rod knock due to lose bearing. thanks

I adjust them when the temperature is at normal operation. the intake is adjusted to .010" and exhaust is .012". I have only narrowed the clearance by .001" for all the valves. Even I have a thin head gasket installed would not lead to the piston-valve contact. The cam shaft is OE. I dont see any excessive wear on the cam lube. However, Im not sure the condition of the rockers. The funny thing is: the knock will go away at higher RPM such like after 2.5K RPM. I suggest it would be unbalance air-fuel mixture or hot-spot in cylinder..

HI guys I just got my EFI 260Z runing few days ago. Everything was fine. Then i started to perform a valve adjustment. Before the valve adjustment, I checked the clearance of the intake and exhaust. The intake was excess .010" and exhaust was more than .012". Refer to the Factory Service Manual, the intake is .010" and exhaust is .012". ok, then i warm the car up to normal temperature for about 15 mins and adjustment is done. after the adjustment is done, the engine started to knock. I wonder if I have adjusted the valve pushing too far so the piston is touching the valve, but it is the clearance the factory want. however, i think the cam is stock after test drove it a bit. I didnt feel lots of power change by comparing to other Z. at this point, Can anyone give me a hind what is going on? thanks

First of all, sorry for my capitalization. From what I heard, the ECU are the same between 75 and early 77. I just pick an ECU from a pick a part at my area. It was a 76 280Z. The ECU works fine on my 260Z and 280Z. Now my 260Z runs fine on idle and acceleration. However, I heard some kind of knocking from the head after I done a valve adjustment with feeler gauge after the engine had warm up for 15 min. I have tight all the locking nut and double checked they are tight. The reason the 260Z was running rough because of the bad connection of injectors. arh. Should found that out earlier. so the 260z runs good and pulls hard as expected. The knocking sound only happen after idle for a bit and first kick on gas pedal. Second kick on the pedal, the sound is gone. what is that?? About my 2+2, it runs very very rich. lots of black smog coming out from the tail pipe. so far, not the ECU, not the AFM, not the TPS, not the Cold Start Injector. It has spark. I have pulled the spark plugs out, and only the #4 spark plug is dry. The rest of all 5 were wet with heavy smell of fuel. What you guys think would be the problem? At this moment. I just run out of idea. thanks all

i have swap the TPS and AFM from the 260Z into the 280Z. the RPM ran up to 6k normally. but then later it stay up to 3K RPM only. and the car has lots of smoke. smell like burning oil and somewhat like unburned gas too. my guess is some of the injector is not functioning. by listen to the exhaust note. it really sounds like having a dead cylinder. am i right? thx

very help links thanks