Am having similar problems with hard acceleration while driving fast. Believe that it is fuel issue; not enough fuel filling bowls at desired time causing a stutter or falter while under load. Check your fuel pressure for level and consistency and make sure your float bowl needles are good. I put a fuel pressure gauge in line to see how my levels are. Noticed that it ranges from 2 to 4 psi and is inconsistent and varies. Have ordered new mechanical pump to see if that helps with my problem.

Edited October 26, 201113 yr by duffman

Am having similar problems with hard acceleration while driving fast. Believe that it is fuel issue; not enough fuel filling bowls at desired time causing a stutter or falter while under load. Check your fuel pressure for level and consistency and make sure your float bowl needles are good. I put a fuel pressure gauge in line to see how my levels are. Noticed that it ranges from 2 to 4 psi and is inconsistent and varies. Have ordered new mechanical pump to see if that helps with my problem.

Good idea, my Porsche had fuel delivery issues as well so I hooked up a cheap fuel pressure gauge to make sure it was getting the right amount of pressure.

Just a note on timing, a stock 240Z should run 5° BTDC at idle with a stock dizzy, not 17°. There is WAY too much mechanical and vacuum advance built into our dizzies in the states. I have had mine recurved to a european advance curve and I run 14° BTDC at 750 rpm.

Just a note on timing, a stock 240Z should run 5° BTDC at idle with a stock dizzy, not 17°. There is WAY too much mechanical and vacuum advance built into our dizzies in the states. I have had mine recurved to a european advance curve and I run 14° BTDC at 750 rpm.

My bad. I took those numbers directly from the 1972 FSM tune up section and I now realize that those would have to be the Euro numbers because, right below in on the chart, it says 5°/750rpm L24 SU twin emission control.