Its always something isn"t it? Help please?

[commplexone]

Hi guys,

I seem to be running into all kinds of problems while trying to work out all the bugs in the Z i just bought. With the advice of many here i have made a ton of improvement. Car has been running good but i have noticed something yesterday and today. At idle i can feel the car "missing" or making a subtle popping noise and i notice that the Tach jumps in sync with the popping. Off of idle the car will hesitate badly unless i rev the engine enough to get her going. I also noticed that this popping will occur sometimes while driving almost like its missing a cylinder or something. I am leaning towards some type of ingition problem since i have correctly rebuilt and rejeted my weber carbs. I recently put new plugs, points and plug wires on the car as well. I dont know what it is really but any suggestions would help a ton.

here is the shake down of my car by the way....

1972 240z with an L24 and dual weber dgv carbs. I also updated to a brand new nissan dual point dizzy like three months ago. On a side note, i am wondering if a new coil and pertronix updrade would help with this problem any?

[Arne]

Dual point dizzy? Is your car an automatic?

[commplexone]

It was originally an automatic car but has a fresh motor and trans in it now to make it a manual. Car was wired for the dual point originally so i put the dual point in it rather than the beat up single point it had when i got it.

[Arne]

OK, that sounds right.

First, the Pertronix only fits the single point distributors, so that upgrade is not viable with what you are now using.

Since the tach jumps when you have the problem, my guess is either some sort of intermittent connection in the wiring to the coil, or possibly the coil itself could be going bad. Start with the wiring, check, clean and tighten all connections at the ignition switch and the coil. Also check the tach connector plug. I'm going to assume that the kickdown switch above the gas pedal is still hooked up, so check connections there, and also at the relay on the inner fender below and in front of the coil.

[Zs-ondabrain]

Get rid of the dual point Dizzy. Go for the Pertronics, E12-80 ZX Dizzy, or the Mallory Unilite. A blaster 2 coil or similar coil would be a great improvement along with one of the prementioned dizzys.

The dual point dizzy is a pain in the butt if you don't have both sets of points set identical. Any time you have an older dizzy, you take the chance of having a bad bearing which causes wobble and therefor your points don't fire off correctly.

jm2c,

Dave