NH-75-Z

Thanks for your insight...I've seen this method discribed on another forum, just didn't know it was the "norm" . FSM....instructions are Pie in the Sky !!! More time on the creeper.....saves at least $500 !!

I guess I'm missing something...to remove rear strut... the FSM says disconnect half shaft, brake line and EB cable, 3 bolts in tower, and remove spindle, then lower strut and change cartridge like fronts .... Different method ??? BTW John and Pete are in Cali...at the convention.... can't interupt their fun !!:classic:

Have purchases 4 Tokico HP cartridges for 75-280. Made appt. at Import auto shop for installation. 2 weeks later, delivered car...and 3 days later no service had been performed. Owner, now wants to "discuss" the enormous job to replace these. The car has not even been inspected by them, and its a So. Cali car with no rust on bolts !! I've already changed all suspension bushings, and even the exhaust manifold to headpipe bolts came off without pent. oil !!!! Is the dreaded spindle pins scaring them ?? What labor hours have others paid for changing all 4 struts ???

I recently changed the tranny in my 75-280 from 4 spd to a 78 5-spd. Although the 5th gear is "better" than the old 1:1 , I had expected a lower RPM for Highway cruzin. Its 3K RPM at 70MPH +/- (3.54 R200 ) . So since both 1st gears are same ratio, I'd suggest the 82 Tranny !!

Last Fall I posted about my 75-L28, N42/N42 burning oil on decel, and due to your great advice, I totally rebuilt it this winter, myself...first time. And its running great.. However, Sat, I took it out for "spirited" driving with the Z car club, touring So. Vermont rural roads... at lets just say... at challenging speeds !! Well its still creating some odor/smoke on heavy decel mode. like long down hills, and going thru the esses.... Its got new rings, head rebuilt by shop with new valves,seals, guides were OK . Compression readings after 500 miles breakin are 160(2) 164(2) and 168 (2) . Manifold vac is 21 at idle. No oil usage to speak of, maybe 1mm on dipstick in the first 750 miles of breakin, and no break fluid loss, so its not being sucked into the intake. Otherwise, it running great. So, what do you think is still feeding the engine to create the puffs of smoke on decel mode? More time for rings to seat ?? Oil sucking by PCV ? Its a new valve. I'm puzzled cause I don't want to be labled the smoker by the club members following me !!

Thanks ...I'll leave it and keep the lights ON !! Z-On ...

Am planning on replacing the fusible links with a gold plated fuse block, on my 75-280, California model Z. I only have 1 fusible link box, located on the relay bracket. It contains 2 links, 1 green labeled Ign, and 1 black labeled batt. Underneath this box, is a metal box, 2" x 2" x 6" and it contains a copper strip, shaped like a "m", and 2 glass fuses. 2 large gauge wires ( 8ga maybe ) one white and one white/red connect to the large metal strip, and 2 light gauge wires, same colors, connect to the 2 glass fuses. My question is : is this unit the fuse for the charging system ? Thus can be replace by 60 amp fuse. FSM shows 2 normal fusible link boxes, but this metal box appears original,connects to harness ,etc. Voltage regulator is mounted underneath this relay bracket, and car has no A/C, so its not some relay.

Yup, ask for some assurance such as maintenance records from garages that often write down the current milage on service repair orders. I bought mine as advertised at 90,000 and was in fact 190,000. Still it runs great, but you could be facing engine overhaul to stop oil smoke at that milage, as I am. Good luck

Well finally I figured out I'm screwed. Bought my 75-280 off ebay and it said 90K original miles. Paid full "buy it now" price cause it was low miles !! Have had it a few months, and although it is now running well after lots of tuneup work, its still burning oil and making smoke. Have changed valve stem seals,etc. no change ! Finally contacted original owner and lo and behold, actual milage is 190K. Contacted ebay seller, advised him of the mistake in advertisement, no response. (imthepappy) Contacted ebay. Since seller cancelled auction early to sell to me (due to a timing fluke and as a favor ) they (ebay) won't post a negative feedback on the seller. So guess I'm screwed into doing a re-ring job to stop the oil smoking. Just venting a frustation... thought that the seller would be man enough to admit to a big mistake and make a small token gesture to make things right. Afterall, he bought it for 750, put a clutch in and sold it for 3,500. Thats pretty good profit. All I asked for was 250 back, to buy the parts!! Thanks, Julio Sanchecz!! I'll remember this !!:mad:

Chris, I can relate... have been adjusting my valves over the last couple of months, while doing compression checks and most recently, replacing the valve stem seals. Have found that doing it cold is easier cause you don't have to rush. The real trick is to apply just enough pressure on the 14mm adjusting nut to hold the adjusting stem in position, while tighting down the lock nut with the 17mm. Have tried both the recommended crows foot or the plain open end 17mm and had better luck with the open end wrench. .08 and .010 is what I used. Sure its not as quiet as the modern valve trains, but it sure dosen't sound like a diesel! Keep trying...Z-On:classic: 75-280 / n42 / Monza xhst / urethane bush /

Make the Fast and Furious look lame...or maybe sane !!!

Posted this problem a while ago...75-280/n42 oil smokes on decelleration mode. All advice was to replace valve stem seals. Since that time I've contacted the original owner to verify milage. It is 191,000 not 91,000 as I was told upon purchase. Well anyway, I just finished replacing the valve stem seals... some improvement on short deceleration duration but on a long downhill, sure enough its smoke city behind me!!! Now what... rings?? some cylinders are marginal or is the PCV valve feeding oil?? I took it out, sprayed it with cleaner and it rattles. But in the FSM diagram, it shows a spring holding the valve ball to a seat. Is this a possible source of oil to the intake??

Have just received my Datsun original FSM for 75/76 280. On page GI-3 it lists color codes/upholstery colors for that model year. My 75 - 280 Vin HLS30 221,584 has paint code 303 on its orginal name plate near the radiator. The FSM lists paint code 302 as leaf Green Metallic, but no 303 is listed. The car is green metallic. I'll attach a picture ( if I can , 1st time ). Is this Leaf Green Metallic??? Z-On ...

On another website for Z-cars ( zcar.com ) there is a very nice slideshow done by Kammy, on adjusting the valves. Log on to that site, either find any post that has Kammys name on it, or use the search feature, and the link will show up as "6000 mile maintenance" . Kammys great for advice . I've done mine twice, I suggest doing it Cold. Doing it Hot takes a lot of practice to get it done properly before the engine cools down. . Z-On ...Gene

I have a California model 75-280, that had the factory cat converter. The item your discribing sounds like a heat sheild on the headpipe section of the exhaust. Its not on mine so your pipe may be an aftermarket unit. In any case, yes it sounds like a heat shield, if the rattling noise is too much tighten it up, but I don't thint its removal is of concern. Z-On ...:classic:

Have heard 2 ways of doing in head seal replacements. Your method of using the compressed air to hold valves in place, and I just got the new compression test kit that has that feature. But also heard that if you take a long length of 1/4" nylon rope and stuff it into the cylinder via the spark plug hole, then it will prevent the valve from dropping down too far!! In either case, I've ordered the stem seals, valve spring tool and will be changing them soon. The National Z-Car convention is coming to New England this October, I just don't want to smoke out the poor folks driving behind me during the events!!!:tapemouth Z-On ...

Hey Mr. Camo... this is what happened ... I got this 75-280 off E-Bay, had it shipped 2000 miles to NH. It started and ran "OK" but sluggish. Checked timing and it was 15 deg retarted!!! Fixed timing, and the thing roared!! Took it out and rev'ed it up to 4 grand no problem, BUT then I noticed that it would smoke bad on deceleration, like coasting down a hill. It did not do that before I adjusted the timing and had it running good. Most responders have said that on deceleration , manifold vacuum is highest, thus its probably sucking oil down into the cylinders causing said smoke. However... I have squirted oil into the cylinders and the compression increased in all...one even by 20psi. Odo says 91,000 but maybe its 191,000 ??? Am expecting a new compression test kit this wk and will be doing a bleed down test with compressed air. Will that indicate stem seals, rings,etc.??? What did I do when it rev'ed to 4K for the first time in many years ... break a oil ring?? Z-On ... Gene:ermm:

OK. I'll chill out. Just felt intimidated by the $30,000 cars I guess. Will still feel proud that I got my hands dirty actually fixing my 75 to run real good. It got me there once and will again. And although I may not make it a pretty garage queen, I will be proud that I have a classic sports car. :stupid:

Well just attended my 1st Z-Club meeting. Didn't know what to expect, but all in all it was a good time. Since getting my 75-280 a couple of months ago, all of my time has been focused on getting it mechanically reliable to make day trips without constant worry of breakdowns. I know this is only my 1st impression with other Z-owners, but it appears that most of their interests are focused on what last HP they can squeek out or how much money they can spend! AT the meeting ( which I traveled 200 miles RT to attend ) most had new 350Zs or perfectly restored 240's (2). Felt quite out of place. Are Z-clubs now just a mechanical extension of one's wallet for status??? Hope not. One should not be able to "buy in" to a classic collectible association of car lovers. Maybe the 350Zs should have thier own clubs, since it is a totally different vehicle. They don't even have a glove box!! Sorry for the rant, just a newbie thing :cross-eye

When I received my 75-280 couple of months ago, I noticed fumes inside often. One day while my hand was on the shifter, I felt warm air blowing up onto it, and by opening the top of the leather shift boot, could SEE THE GROUND below the car. The rubber inner liner was completely rotted away. So the first thing to do on an old Z, is replace all of the original rubber stuff. Including swaybar bushings, steering rack bellows,hoses etc. Anything that is rubber from the 1970's is junk today!! Due to age and heat deteriation. Good luck:classic:

Have been posting on a number of Z-car tech forums a similar question. Most discussion on compressions readings your seeing is that they are on the moderate low side, 170 being a new engine. My high is 150, my low is 125/130. Most responders have said its valve stem seals, just to live with it till time for a real overhaul. Engine still runs fine at these pressures, so I don't think its a clunker, just not real fresh.