Black exaust smoke

[mdixon]

I bought a 71 240 for less than $800. I have had 3 240z's in the past but never tried to restore one. The interior on this car was in mint condition(well worth the $800 alone). It was not in running condition when I bought it, but I cleaned the carbs, replaced some hoses, new plugs, dist. cap & points, and now she runs. Not well but she runs. Some days she fires on all 6 cyl. and some days only on a few. I plan on buying a pair of reman SU's from Z therapy soon, but untill then the manifold is leaking so much fumes it is hard to stand in my garage while the car is running. I want to buy a header and new exaust so I can at least try to work on it a bit. I do notice a great deal of black smoke coming out of the exaust. Will that quit when I get new carbs and adjust the timing and valves.

Thanx,

Mark

[2-4-T-Z-MAN]

Mark,

Black smoke usually means that you are running too rich a mixture.

New carbs might take care of the problem if they are adjusted correctly.

A tune-up might be needed.

Why are you getting a new set rather than rebuilding the ones you have?

[zeiss150]

If I were you I would just send my time and money working on the carbs that you have now. Is sounds like they are running to rich. there is a screw on the bottom of each carb turn both of the screws "UP" equally untill the black smoke stops. If you turn them all the way up and it still is smoking black then you might need to replace the "nozzels" and "needles". It caust $60 from Ztherapy. If you car is a 71 it will have an E88 head and that head has brass valve seats. They are probably not makeing a good seal anymore. you should pull the head and get the vavle seats replaced with new steel seats and have your valves reground. And if you do that make sure you replace the valve stem seals. If you do all of that and you still have smoke then you will have to do a ring job. But while you have the head off you might as well do a lower end rebuild. I bet if you just spend some time on the carbs and adjust the valves you'll find that the car runs pretty damn good with out rebuilding anything.

Good luck and keep us posted.

Matt-

[mdixon]

Thanks for your advice. I thought about rebuilding the carbs myself, but was a bit intimidated about doing it correctly. It sure would save a lot of money to spend on other things. Like I said I have had Z's before but never really done any work to them. I guess I will try to re-build the carbs myself, but I'm not sure I am qualified to open the engine. I wish I had someone who knew about Z's in North Georgia who could help me do this stuff.

Thanks again,

Mark

[zeiss150]

Hey Mark, Let me try to give you a little inspiration. A little less than 2 years ago I had never worked on an engine other than changing the oil in my car. I read a few books on rebuilding Z car engines and now im building my second one. If you are at all mechanically inclined you can rebuild the engine. As far was working on the SU's Z tharapy has a DVD called "Just SU's", it will walk you through a total rebuild and carb tuning. They also sell a tune up video that is great if you want to learn how to adjust the valves. The videos are about $20 each, well worth it. Think about it this way... if you mess it up you would wind up paying someone to fix it but you would have had to pay that in the first place if you didn't try to fix it. If I can do it anyone can do it. Good luck and have fun.

Matt-

Rock on Z People

[GunnerRob]

Hi Mark.

I say "jump right in there" (with the help of the videos and the good people on this site). I think you'll find that the SU carbs are pretty simple in design. When I was 17 I had a guy who raced MGB's help me rebuild the SU's for my MG Midget. I was like you. I'd never done anything like that before. But after getting into it, I found there wasn't nearly as much to them as I had imagined. We not only rebuilt them, we also set them up for racing! Very simple. I was glad I didn't let fear hold me back because that experience, which took place more than 3 decades ago, is still fresh in my mind as one of the automotive highlights of my life. I just wish I still had that MG! It would have financed my 280z restoration project!!!

[mdixon]

Well, I'm convinced. I will do it myself. While waiting for the carb parts, I have decided to tackle my brakes. I took the front tires off, no problem. I was able to replace the pads, no problem. I was quite surprised that the part that pushes the pad against the rotor was not stuck into position. This car has been sitting for several years. Had a little trouble getting the unit that holds the pads off but was able to do so with a little WD40 and a rubber hammer. Then came the rotor itself. I got the rotor off the car, but the part where the lugs are is so rusted on the rotor I may need to use a chain saw. Not really! I'm thinking of heating the bolts with a torch to see if the metals expand at different rates. Is this a good idea? I believe if I try to force it with WD40 and a hammer, they will break.

Thanks for your continued help.

I will try to take some pictures of my car and post them so you guys can follow my progress. It is going to be a killer car when I'm done. I want to go for the look of the white car on this sites home page.

By the way, this car was purchased by an Army sargent who was stationed in Japan in 71. He came back to the States in 72 and had the car shipped over. I have all the bill of ladings, as well as a hand signed letter from Datsun thanking him for buying a Datsun.

It also has the headlight covers with the crome rings like the fairlady Z's

There is still a US Army base in Japan sticker for 71 and 71 on the windshield.

I thought that was cool history.

Mark

[GunnerRob]

Originally posted by mdixon

Well, I'm convinced. I will do it myself.

Hey Mark. I'm glad to hear that you're going to do the work yourself. I'll tell you, from my experience, doing the work myself give me a great amount of satisfaction (when it worked!).

Originally posted by mdixon

By the way, this car was purchased by an Army sargent who was stationed in Japan in 71. He came back to the States in 72 and had the car shipped over. I have all the bill of ladings, as well as a hand signed letter from Datsun thanking him for buying a Datsun.

It also has the headlight covers with the crome rings like the fairlady Z's

There is still a US Army base in Japan sticker for 71 and 71 on the windshield.

I thought that was cool history.

Mark

Ya, that is cool to know about the history and that it came from the "home country". Is it a right hand drive (HS30) car?

[zeiss150]

Hey mark, Im glad to hear your going for it, we'll all be here to answer your questions when you get stuck. now about your breaks.

1. why do you want to take the rotor off the hub? you can get the rotors turned while there still on the hub.

2. consider a bitch'n brake up grade. I did it and it is super easy. check this out

http://www.zhome.com/ZCMnL/tech/Calipers/toyotaCalipers.html

My local napa auto parts store has rebuilt 1983 toyota calipers for $50 each including pads. so for about $100 you can stop on a dime:D

3. since you have taken off the rotor and hub combo now would be a good time to replace the oil seal and repack, or replace and repack the bearings.

4. Drain, flush and replace the break fluid. It's a pain in the but but its worth it.

5. If you have about $80 you can replace your rubber break lines with stainless steel for a little firmer break pressure.

Good luck dude and keep us posted,

Matt-

[mdixon]

Thanks for the info. I was hoping I could get the rotors turned with the hub on. I got the bolts off, but the hub will still not come off. I have bought new steel brake lines, and plan to replace all brake lines.

It is a left hand drive and always was as far as I can tell.

I just got my income tax check so I will be doing a lot of upgrades in the near future. I will stay in touch.

Thanks,

Mark

[ChrisA]

It takes a little persuasion to get the rotor off the hub. Very tight maching tolerances. Just take your time. I found rotors are pretty cheap if you mess one up removing it from the hub. Use a little antiseize when you reassemble them. Next time will be much easier.

Good Luck.

Chris

[venom42]

Have you tried PB Blaster? It is leaps and bounds better than WD40. What part of Georgia are you in? I live in the Acworth/Kennesaw area (northern 'burb of ATL).