My 88 Mach VII now will cut off and I have to restart it in traffic. Any ideas on what could be causing this?
Reasons can be numerous. Try checking for any codes with the EEC IV system, or giving it a tune up and check things like fuel pressure.
This could be a lot of things, common items were heat faults in the ignition module and distributor pickup, so replace them as a set, others were the Idle Speed Control Motor, sometimes they get dirty and would either stick or were too slow to respond to ECM commands, cleaning sometimes helped but eventually they had to be replaced, I did see a lot of sensor grounding issues and corrosion getting into the mail harness causing all kinds of false readings and intermittent connectivity issues, and ignition switches, for some reason Ford ignition switches tend to just come apart over time. Hope these helped in tracking down your problems.