Very High idle on stock carb. problem Help

[1arky]

I am new here and glad to find a space that I see other datsun owners!I grew up in and around old cars,my dad owned a auto parts(before Auto Shack- AKA- Auto Zone) put the little man out of buis.in a big town. I restore two 70 ss's and one 69.Kinda got away for it all since my divorce.So been eyeing this all original stright body,no rust 1979 210 with 54,300 original miles on it.The original owner was a ''know it all'' so I just listen to him tell me what was wrong with it.Lets just say he was a neighbor..The car would not idle,so he put a carb kit in it...and it didnt help..he ordered a new/rebuild carb off the net 300.00..They said it ran good for a few days but I dont know ,Anyway the car sit for awhile and I told him I would like the car because of childhood memories of taking a long trip to Dogpatch USA when i was just a child and the car was close to 80% new..well new old stock LOL.To shortn the story I bought the car and put it in my shop and started the basic test,compression (180 PSI all 4 cyl)all checked out ok.It wouldnt idle so I thought it was the intake manifold,shot some carb cleaner around the gaskets and she smooth up so I began my first ever working on a datsun.Went ahead and bought a full gasket set upper and lower.As I was removing the 1.4L intake /manifold I notice that the main leak was a blown gasket under the carb that was blown out(maybe from backfiring)not the original intake manifold gasket as I thought of corse it may of been leaking some but that was the main vain.The baby had a 1 inch suckin air valley !!No wonder she wouldnt idle!! Got her int/maifold cleaned up good and shucked all the smog shiz,(REMOVED ALL SMOG,pump,egr,lines in a box,pluged all the inlets and outlet so I timed her,checked corect plugs,gap,and the vaccum advance is bad as of now but that should not be why it is at a high idle.So I fired her up and she ran smooth but with a very high idle,well I thought I had a vaccum leak,next day or two I plugged and and plugged dubble checked.Iv ran the idle screw all the way up and I did put thenew carb that the original owner bought befor he sold it to me back on it,It's base plate has an extra vacumm outlet,so iv been thinking I would put the original carb back on it and see if that would help the fast idle,and you may wonder how fast it is idling,Iv been driving it about 1 month(thinking of selling it of keeping it)Iv never owned a rice burner but it grows on you and iv not seen one on the road yet and I drive alot.Well back to the fast idle,you can let off the brake and it will get up to 35 on a flat road..LOL it's an automatic trannie too and that one strong baby also fluid is brite clean and dipstick clean shiny,that was a concern to me how the trannie shifted out.The anti -deisl valve was checked ,,well i checked it by putting 12volts to it to make sure it was working,iam not sure its working while its installed,but with the cheep gas it run backwards but if i run mid-grade 92 100%gas no methanol she dont run backwards.My question is where would you start if i have NO vaccum leaks ?Timing is around 5-7 fast and the vaccum advance is bad but all outlet are plugged and the only vaccum iv not checked as iam here thinking about it is the vaccum running to the trannie but she shifts good and down shifts good I just dont think that would make it idle that fast..Iam leanning toward putting the original carb back on it..Any advice from you guys that live and breath these cars might cut me some down time.Going to love this site...Thanks Charles in arkansas

[1arky]

[1arky]

[ggzilla]

> The car would not idle,so he put a carb kit in it...and it didnt help.

 

Number one cause of "not idling" is that the anti-diesel valve is not hooked up or not getting 12V.

 

> The anti -deisl valve was checked ,,well i checked it by putting 12volts to it to make sure it was working

 

Check it this way: Engine OFF, key ON. Connect and disconnect to AD lead, it should click each time. If it doesn't click, it is stuck.

[ggzilla]

> I fired her up and she ran smooth but with a very high idle

 

That's normal for a cold engine. It's supposed to run 1800 to 2200 RPM when the engine is cold, but when warm, you can "kick down" the throttle and it should idle at 750 rpm or so.

 

By the way I've been running inexpensive gasoline 10% methanol since 1989 with no problems. Stock carb is what I prefer to get the optimum fuel economy. The A14 is a medium compression engine designed for unleaded regular. It does not require high octane unless extensively modified.

[1arky]

Thanks for ur imput I will dubble check the valve,I have 2 and checked both of them off the car with a 12v battery,you could hear it click and will check it again but iv put about 1000 miles on it .4 gas stations in my county sell the 100% gas and I use it in my outboards and just about anyting that requirs mixing or high octain.(the ethanol will deterize your rubber lines and in turn if you have to use a splice or a line use the alcohol safe.The 89 octain is what theoem manual book says in min.octain and IT STOPED THE DEISLING and improved the milage 2-4mpg.

I will get it right just not had the time.Thanks for ur help n imput.

[ggzilla]

If the AD valve is working, it will also stop the dieseling. Either way. The dieseling is not because of the compression ratio per se, but it may have some crud on the valves which effectively increases the CR. That's why the 10% alcohol is good, it cuts down on the deposits. Unfortunately once your engine gets them it will keep them until you tear it down and use a wire brush to remove the deposit crud.

 

Thankfully, Datsun fuel lines are alcohol resistant.

[1arky]

Close friend that owns a ''pure gas'' station said and I checked it by way of the web.they are starting to add 15%corn to the gas and they dont have to change that on the little stickeron the pump that is printed up to 10%.If you like the corn whiskey you will like the 15%huh?The e-85 fuel is for the flex fuel burners 85%corn whisky((the added sumin to it so u cant drink it)LOL

[a.d._510_n_ok]

my 510 had sat for a while and had the crazy high idle that wouldn't kick down even after the engine warmed so I did what I used to do when my Darts, Valiants, Falcons, Comets or Fairlanes had fuel issues from sitting, i.e., ran a gallon or two of diesel through them once a week until everything smoothed back out. I'm not saying it will work for all high idle issues but it cured mine.

[1arky]

It's fixed now,had a carb from a 82 210 on it,I rebuilt the original and its purring like it should.I need a vaccum advance now.Where is a cheep on located?

[banzai510(hainz)]

nissan or rockauto.com?????

[ggzilla]

Just plug the hose to the vacuum advance and it will run fine. Only fix it if you want for fuel-economy.