Ok just to give you guys an update of "my problem". I think it was a question of tuning the carburetor, because i put the idle a little faster and now the car doesn`t die when i stop in traffic or in a red light. What i noticed is after time driving when i stop the engine dont sound "straight" it sound like accelarating and disaccelarating but never die.
I tuned by rotating that screws beside the rocker cover, one is more out than the other, i mess with those two but sincerely i don´t know what are they do exactly!

Thank you all

P.S.-I checked all hoses to and they were fine, just suspect the carb gasket is leaking a bit!

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The idle mixture is too rich.


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One of those screws is the idle mixuture screw.

Always start with the basics, and your task will be easier.

Quote:Oh for gods sake, all this screwing around over a simple tune up job that should take no more than an hour including a coffee break & taking three calls on the mobile/cell phone.

If one can actually change the carb, then one should be able to read the manual, follow the instructions to the letter using the tools & instruments that are required &, providing that there is no actual mechanical fault, have the engine running as sweetly as the manufacturer intended.

Don't have the tools & instruments? Then either get them [buy or borrow] or give the car to somebody who actually has a clue.

Sorry fellers but this problem has been ongoing for something approaching two weeks & it's seems to be a simple enough job to diagnose & rectify but instead it has been nothing but 'what if's' & 'try that's' when all that's needed is a simple tune up as per the book.

It aint rocket science.
Quote:Sorry mate but if you do not have the faintest idea what you are doing then GET THE MANUAL & read it. This will tell you what the screws are for so you can stop messing with things you know nothing about.

Let me give you an idea Dodgeman what are we talking about. Add something you don`t know anything about, or know very little of it, just like let`s say rocket science and grab a portuguese manual, you should get the picture how i "see" the things.
It sounds easy for you but belive is hard for me!

My point is that a workshop manual [preferably in Portugese] will cut short so very many of the problems that you are having yet nowhere in this thread do I see anything that suggests that anybody is using one.

You are clearly able to read English much better than I can read any other language [which makes you smarter than me] so even an English language manual would be better than nothing. The popular Australian 'Gregories' manuals are very good & are writen for the home mechanic with lots od useful pictures & they are not expensive on eBay.

Anybody who wants to look after his Datsun at home should ensure that they have a workshop manual as one of their first purchases once they buy the car.

If you can get a suitable manual locally then I strongly recomend it, if not, then search the world. The 120Y/B210 was quite a popular car & a suitable manual should not be hard to find, but will save you many hours of frustration & many [insert unit of currency here]

I have Haynes Manual, but in some sections is not precise and there are some terms i don`t understand. Thanks for your help and your tips, in the end it was your tip on the basic tune, that put my car running (bad but running!!), but i will give it to a competent mechanic to make the final tune!

If you can get a vacuum gauge you can achieve many good things when tuning your engine.
I have a big old workshop type that my stepfather was using in his service station back in the 60's. I now use it, as well as a hand held tachometer, at any time that I do any carb tuning so as to get the very finest adjustment.
Works for me.

A basic tuneup is not always the answer on a 33 year old car, which it sounds as if it has not been cared for properly. Not everyone understands basic car mechanics and it cannot be explained to them by reading a manual which was written in technical terms for a person with a fair bit of knowledge. I thought that this and all other forums were designed to help out the people that need to get along in life without being treated like a moron or a drag on our time. Back to your "77" you can fiddle with all of the adjusting screws but it won't cure the problem of why it went from runnig fair to poor, no one went under the hood and adjusted them while you were not looking, you have to find the source of what caused that change. This brings me back to the earlier posts if you would like to read over them again. I hope you are able to solve your Datsun issues, as for myself I would be glad to respond to any future posts you may have.

Thank you Eric. Your tips were very helpfull and most of all insructive.
There are some things that books don`t explain and as people relations, helping others and solidarity concern, this kind of foruns and chats are the better way.

THANK YOU ALL!!!

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Well you are partly right.
A proper tune up will establish a baseline & if it doesn't fix the problem, it will eliminate many possible causes from the diagnostic process.
This is what I had writen in a previous post. [Post #17]
After all, you can't fix a problem if you can't diagnose what the actual cause of the problem is.

Workshop manuals?
I rather like the Gregories manuals because they are writen for the home mechanic more than the professional & this is why I recomend them. They have plenty of pictures & clear descriptions on how to perform most tasks that a home mechanic might try to do.
They even have a list of the tools that would be required, or at least mine do.
I had also writen this in a previous post too [Post # 25] so the comments about the tune up & the manual only show that not all of the posts were actually read before commenting.

A Haynes manual is one that I don't have so I can not comment on the quality of the instructions but I'd have to agree that my Inter Europe manual is not as good as the Gregories.