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Discussion Starter · #1 ·
Well, I just totally overalled my carbs. I have a 70 240Z and have cleaned everything perfectly. I took off the intake manifold, exhaust manifold, the carbs all of the emmission stuff cleaned it all up and reinstalled it torqing all bolts to spec. I put in new points, pluge didt. cap and rotor and rebuilt both carbs with a standard nissan kit. I totally cleaned the carb and they look like something for a show. They are in great shape and all all likages have been cleaned and lubed. The car fired right up however it idles to high and I cannot reduce the idle speed lower that 1300 rpm. All idle adjusting screws are where they should be. the ones that are on top are not touching anything. If I tighten any of them they just increase the idle. The idle jets on bottom are turned out 2.5 turns each and it runs great however there is fire comming from the exhaust. I runs smooth but the fire worries me a little. If I turn in the idle jets out more, more fire comes out. I do not know what to do?? Can someone help me out here.
 

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hello. well first the fire would scare the heck out of me...what did you clean the manifolds with??? is this combustable cleaner >> do you have gas leak under carbs did you check the floats, somtimes removing the carbs you can mess up the floats id check those...as far as the idle are you sure you hooked up all the emissions stuff correctly...are any of the emmisions compoinents pluged off and are the plugs leak proof??? how about the chokes are they set at the bottom of the carbs??? chances are you have a vacumme leak or your chokes are pulled out . try to back off all the adjusting screws that go to the carbs to slow it down...if it does not slow down check the rubber hoses for the emissions and the chokes . whta ever you do be careful with the fire...michele
 

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I had a similar experience which was caused by a vacuum leak. Get a can of starting fluid. Spray it toward any place that has a seal. The rpm will pickup noticably when you find it. Remember to keep looking there can be more than one place.
Good luck
Don Pappe, Seattle
 

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ok i dont know how to explain this but i had a similar problem.. when i put the linkage back on there is a piece on the carb that the linkage pushes up and down.. check and make sure your tab from the carb is between the two linkage pieces and not underneath them both..youll have to pull the carbs off again to change this so bring your wrench.. thats what happened on my car anyway but its a 72..but it sounds like somehting similar... good luck.. email me if you need clarification or any other help
 

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frame and under part of the car

i got a 280ZX and the front right part of my frame is starting to rot! and miner parts of the under body to. I was wwondering if theres any way too stop this from happening cuz it's really buggin me and if anyone could give me some good tips it would make me really happy so someone get make too me on this pls.
 

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I would'nt use starting fluid due to its explsive nature,if you use WD-40 it will be a lot safer and at the same time cleans off very well,it does sound like a vac. leak, also check your timing.
 

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Discussion Starter · #7 ·
Well, I rebuilt them except I did not mess with the floats. Probobly a mistake. After cleaning the heck out of them and replaceing the needle and seats, I just simply put back the floats as they were.,. Do you think these floats are not adjusted properly. Also when there is no vaccukme from the emmision stuff the engine does idle much differently. I do not think it is a vac leak. I am leaning toward the floats being missadjusted. It seems like the mixture screw on the front carb does not do anything, or very little. Also when I tune it so no fire comes out the the car backfires when I give it quick throttle. I backfires on the rev down or when I deaccelerate. Another thing when it seems to run smooth it smells like unburned gas and it hurts my eyes. This seems like the car is too rich???? when I lean it out the car breaths fire this does not make logical sence does it???
 

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First, make sure that you plugged off all vacuum connections on the manifold. Second reset the float levels, or you will never get the mixtures correct. Next, if you removed the throttle positioner (dashpot device that attaches to the manifold and a cannister shaped vacuum controller), you will be more likely to backfire on decel. Next when adjusting the linkage you need to disconnect the front to rear linkage. You do this with the rear screw on the LINKAGE. Then you can back both throttle stop screws out and then just run them back in until they just touch the stops. Then turn both in perhap a 1/2 turn. If you don't disconnect the front to rear balance, you will not be able to balance the two properly. Do you have a Haynes or FSM?
 

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Timing?

Did you do anything with the timing or remove the distributor drive gear? That sounds like the timing is too far advanced. Mine was way far advanced and it shot big flames on deceleration and would not idle lower than 1200 rpms. Just a thought.
 

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LEAN, way too lean!

You missed a gasket or something, as that sounds like some mean vacuum leak!
Ask gearhead, that's how he blew his headgasket!
heh heh...
 

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Disreagar my "Lean" post!

I just re-read the original post, and realized the f"flame" was coming out the tailpipe and not the carb!
Gearhead is probably right, too rich and timing off.
He should know, "King of Ping", "Blower of All Headgaskets", "Nuker of Nissandom" etc etc etc...
 
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