72 t with e spec motor, webers, new msd, new petronix, running issue, please help

[Ccamut]

Just installed new msd, and petronix, car runs great, in first gear pulls to red line, second gear car won't go past 5500 rpm, same in third gear.

Other wise car runs strong.

Any suggestions?

Thanks for the help.

[ibmiked]

Sounds like you have a problem with the rev-limiting rotor in the dizzy.

[Ccamut]

It sort of feels like that, however I have a non rev limiting rotor, and have te msd set at 6800. I just drove some more and it just dies under load.

I am beginning to suspect the coil. After suggesting to my mechanic 20 times that I need a new coil he insisted the old style coil would work.

Any thoughts?

Do you absolutely need the blue coil with the msd?

Thanks again.

[gsjohnson]

I'm running an MSD blaster coil painted black. What's the total advance on your timing?

[Ccamut]

34 degrees at 6000.

[gsjohnson]

Hmm...your in spec for stock E cams. Getting full throttle? Carbs freshly rebuilt? Fuel tank and fuel filter clean? No blockage? Check fuel pressure?

[Ccamut]

Yes getting full throttle, just installed 32mm venturi's Carbs are clean and in good working order. Need to check fuel pressure, but not reason it would have changed ......nothing else changed other than the MSD, would the msd, require more fuel? meaning running more efficiently, therefore need bigger jets? Carbs are new to me, so trying to familiarize myself with how things effect one another.

[Ccamut]

BTW, drove it about 120 miles, no real hesitation, or large miss, just a wavy power band in 2nd 3rd and 4th. it really dies at 5200 in second, then slowly powers through, 3rd the problem comes on at 4K and then slowly powers through, full throttle in 4th creates a wavy power band, not smooth and zippy.

very strange.....i feel its electrical, rather than fuel related. ordered a blaster coil and will see if that helps, any other thoughts appreciated.

with the MSD, car starts right up, idles great, accelerates great, hot start great, in many ways runs better, just this power issue.

[304065]

Absolutely it's the coil.

Trying to run the original blue coil, which has an internal ballast resistance and very high inductance, with the MSD box, which is spec'd for a very low primary resistance coil and moderate, but not huge inductance, is misinformed advice. Probably what is happening is that at higher RPM the coil is not charging the capacitors fully due to the high inductance and resistance. I bet the MSD coil cures it.

[gsjohnson]

Something else...Did you install new plugs and increase the gap as recommended?