240z is choking

[daddiodanger]

have a '73 240z, automatic with two weber carbs. i've been tinkering with it for a year or so. sometimes its a rocket, most of the time it's a turd. it's weird.

anyway, up to half throttle the engine is fine, but anything more, nothing. the tranny downshifts and the engine feels like it's choking.

i've replaced all the carb gaskets, cleaned the crap out of the filters, adjusted and readjusted, and readjusted the carbs. changed the points to a pertronix HEI, new pertronix coil, new wires, cap, rotor, plugs .033 gap, oil change, new muffler, replaced the intake/exhaust gasket. i think the timing is set at 9 degrees advanced.

i live in reno, which i think is somewhere between 4 and 5 thousand feet. and i've been wondering if that is part of the problem.

any ideas? i'm not looking for anything to major, cause one of these years i'm going to put a 350 with a manul in it. it would be nice to go down to the local Kragen to the chevy 350 aile and buy a $5 part, instead of searching the planet for a damn tranny coolant line, which i still haven't found by the way.:lick:

[beandip]

Welcome to the club. I am sorry but I cannot help with the Weber's . If you had the SUs that would be a different story. I am sure there is someone here that can be of help. I just wanted to welcome you to our little group . Gary

[daddiodanger]

thanx, thats pretty cool!

in addition to the other parts i replaced. i replaced the mechanical fuel pump along with the filter. the car seems to run rich most of the time. i kinda figured it was cause of the two carbs.

another problem that seems weird to me. the #1 and 6 plugs carbon foul while the #3 and 4 plugs seem to get overheated, and #2 and 5 are fine. i've tried to find some vaccum leaks, found a couple fixed them. the throttle shafts leak fuel a bit, too.

[DRBall]

Yes where your at 4000' will change the way the carbs work...Have you changed the jetting or found a high altitulde kit....The timing might also need to be changed...Most cars are built with those adjustments. I'm not from there but it's a problem when I drive up there....Is there anyone on the board from the Rocky Mountain State's....Or check the FSM and the Weber book for more info....

[DRBall]

BTW the tranny coolant line is it a hard(metal) line or formed rubber? If it's rubber just get the right length and I.D. and have at it..Or give your Nission dealer a call....

[daddiodanger]

the coolant line is metal. i just cut the cracked section out and replaced it with a rubber line temporarily.

i was wondering about the jets. i didn't know they made a high altitude kit, i'll look into it.

thanx

[DRBall]

I think there is or you check with Weber as to what calibration set up for the jets etc you need...Just remember when you low go down to the central valley your car may run different....Just a quick check ,if it runs better in Sacremento than in Reno then that's the trouble...If it's metal goto a radiator shop and have a pipe made....Or any place that works with small diamiter pipe..Or try the HELP section at NAPA...Brass is brass...