Recently swapped my 1.5 ohm Petronix Coil and 3.0 0hm resistor with a MSD Blast coil with no coil. Car runs much more better and does not hesitate on traffic jams. Problem is tachometer is not working. How can i fix this?

Do you mean you replaced the Pertronix with the MSD Blast and no resistor? When we replaced the original coil and resistor in my car with a Pertronix and no resistor the tach wouldn't work. I added a TachMatch device. It didn't fix the problem initially, but the entire setup mysteriously began to work almost a year later. It's possible that the tach would have started working again without the TachMatch, but the scenario you've described is one of the use cases for it and mine's continued to work perfectly all summer.

1 hour ago, davewormald said:

I added a TachMatch device.

You didn't mention which TachMatch Device you installed? I did a ZX matchbox distributor with removed resistor on my 12/70 car. My tach almost works but doesn't seem to go any higher than about 3500 RPM.

Here's the wiring for the E12-80 and the TachMatch's for 240s. Mine works great with Blue's Tech Tip ZX swap so I've got no issues in this.

Blue's ZX swap...

TachMatch's diagram. You'll have to open in another window. I couldn't figure out a way to copy/paste for side by comparison.

240ZTachMatchWiring.pdf