Trying To Mantain My Idle In 1000 Rpm But Not Possible

[jalexquijano]

Ok! You guys are great giving me advice!

 

Just to be sure i will only need to install a working Servo diaphgram to my car before installing the Sanden 508 compressor and Vintage Air Gen II Mini Evaporator:

 

 

Please confirm if i will also need the Throttle opener valve shown in the first picture  or this is not needed?

Edited March 24, 2015 by jalexquijano

[Chickenman]

I can't remember exactly what that large vacuum valve above the left side carb is... but you don't need it. ( Some sort of Emissions device )

 

I also used to own a couple of early 240Z's. Both 71's with early style SUs. My street car had a local regrind ( Shadbolt M445 ) that is similar in specs to the Shnieder 274. 10 to 1 CR, Ported and Polished head, Cannon 2.5" exhaust system. Revved to 7,000 RPM. Idled just fine at 1,000 rpm, with a pretty heavy " rumpita rumpita " though. Sweeeet. . Took some distributor tweaking though. No AC however....

 

For the AC throttle kicker you may be better off get an Idle " kicker " solenoid off of a mid 70's or early 80's GM carburated car. These are an electrically operated solenoid that extends and retracts to raise the throttle speed.

 

They are designed for a 100% duty cycle and are very reliable. Cheap too. Much easier and cleaner to install than all of the Vacuum diaphragm junk. Since the factory AC system uses an electrically operated Vacuum valve ( Called an FICD ) to actuate the " Kicker " vacuum diaphragm, you can just take the electrical wire that actuates that FICD valve and run it direct to the GM electric solenoid. Fabricate your own bracket and you have eliminated the most troublesome and unsightly parts ( vacuum parts  ) of the AC idle " kicker " circuit.

 

 

Edited March 24, 2015 by Chickenman

[jalexquijano]

i think that when you turn on the headlights you are asking the alternator to provide more power, which takes energy and slows down your idle. electricity isn't free - requires work to generate.  mine does that exact thing and it's a 78 280 with efi - no carbs or timing issues. i can turn the lights on and idle drops 100 rpm, turn 'em off and it goes right back up again.

What if i replace this Bosch 60 amp Alternator with a Bosch 125 amp alternator? Will this help me keeping the idle up when i turn the headlights on?

[rossiz]

i can't say if one alternator will produce more power with less drag than another - that would be an efficiency issue.

 

again, the electricity you are generating is not created by magic - you are converting mechanical energy (the pulley being rotated by the engine) into electricity, same as if you were using a windmill, water wheel, or one of those flashlights where you crank the handle. the efficiency of the conversion determines how much energy input is needed (drag on the engine) to supply current for a given draw (the lights). 

[madkaw]

I ran that cam on both SU'S and triples and it idled fine.

[jalexquijano]

What if you add an Air conditioner system? Is 60 amp alternator still enough or are you pushing it?

[jalexquijano]

I ran that cam on both SU'S and triples and it idled fine.

Madkaw,

 

I have the front carb set at 3.5 turns and the rear 3.25 turns. Still hesitation when releasing clutch and engaging first gear. Either i step smoothly on the pedal or step hard, otherwise hesitation begins. is this normal????

 

Another problem i still have is the idle. If i leave the car in the parkway at idle for more than 10 minutes, it drops to 700 and rises back to 1000.