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Correct Rpm At Idle And Choke Adjustment On 240Z

March 18, 20159 yr

The SU choke linkage not only lowers the jet tube to richen the mix, it also mechanically actuates the throttle linkage to increase idle speed. The interconnecting rod can be bent to adjust how much idle is added with how much choke lever actuation.

It does take some time and twiddling (technical term, sorry I know...) to get these inter-related items all working together properly.

Edited March 18, 20159 yr by zKars

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March 20, 20159 yr

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comment_466061

800 rpm is purrrrfect for a nice idle
The choke is used primarily to add more fuel to a cold motor because so much of the fuel vapour condenses in a cold engine and can not burn. The way Nissan designed the choke linkage, it does increase the idle ~ 200rpm.
Since you are in Panama, you do not need to ever use your choke as the engine is always warm. I would not worry about it.

I took the car back to the mechanic so he could doublÃ© check there were no vacuum leaks. Now with this 274F Shneider cam (1850-6000 RPM) i have to drive the car differently compared to the Far 311 Race Cam where i just touch the gas pedal and it showed the power. Is this normal with a stock cam??

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March 20, 20159 yr

comment_466068

The 311 cam seems to have less valve lift (0.473") than the 274F (0.480")

The 311 cam seems to have 330degress of duration vs 274 degrees for the 274F

Both are moderately aggressive cams that should have more higher RPM power than low rpm power. the 311 should suffer more at low RPM's due to the long duration.

Is it possible the mechanic changed the Cam sprocket timing when the cam was changed?

Edited March 20, 20159 yr by Blue

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March 20, 20159 yr

comment_466070

Cam timing was my first thought also. We used to screw around with offset cam sprocket keys in V8s(drag racing). A few degrees can make a noticeable difference. Also I once installed a Toyota timing belt 1 tooth off. oops. Gotta love non interference engines.The engine had little bottom end power but at 3500 rpms & above it acted like it wanted to rev to 8000. I didn't try it. Check out the cam timing & eliminate that possibility.