Z died - won't start back up again

[EricB]

'72 240Z w/roundtop SUs

brand new rebuilt engine

Carbs just synch'ed and tuned.

Yesterday afternoon idle becomes a bit erratic (jumps down - wants to die). No other problem.

After dinner go for a drive and car dies at the light.

First guess: out of gas - added a couple gallons - no start

Pushed to gas station checked wiring, distributor, fuses, spark plug wires - nothing's out of whack...

car won't start though.

starter does turn

battery voltage is still (somewhat) there

lights, horn, etc works.

ideas?

bad coil?

good luck finding one on a sunday in Los ANgeles, right?

[ZmeFly]

the coil would be my first guess. start there.

[EricB]

coil was changed

distributor was changed

resistors were changed

sparkplug wires were changed

battery is fine

and yet there's still no spark....

[LARRY LERMA]

This may help in your case or not but it has always served me.Things are needed for your beauty to run ignition at right time so check for spark at plug take out a plug wire attached groud plug look for spark ,if none start backing up the ignition system with 12 volt tester.POWER TO + SIDE OF COIL?Take coil wire off at distributor and hold 3/8ths inch from a ground and crank over checking for spark,if you have spark there but not at spark plug your cap or rotor it kerplunk,it's just a step by step elimination.Also you can draw a picture of ignition system and use it to cover all bases.Next you need air so check for a restriction.As for fuel you can pull a hose off carb. supply ,crank and check for flow ,be careful here maybe have a can or bottle for fuel to go into.Again start backing up the fuel system till you find your problem.You said I believe that engine quit at stop light,was there an over flow of fuel (stuck float will do this).This all may be too basic for you and if it is I apologize but it's worked for me in 20 years in Naval Aviation and 27 years as an auto mech,

. all the best to you.Larry LMLERMA@msn.com

[classic240z]

My '72 did the same thing. One of the carb pistons was dirty and getting in a bind. You might try taking them out and cleaning them up. Before you take them apart, check to be sure the pistons move up and fall all the way smoothly. Sometimes the top of the carb can put things in a bind, but you can sometimes thighten or loosen one of the three screws (trial and error) and get things moving free again.