i have a 92 mucury topaz that runs fine for a few days then cuts out without warning. ive replaced the computer,distributor,plugs and plug wires, replaced all censors control moduel, found no loose wires and fuel injector works fine and none of these solve my problem so what shold i look at next?
Just to clarify something but have you replaced the ignition module? (the little gray thing on the side of the distributor)
This car is a TFI model and these modules are prone to failure.
Other possibilities could be the electrical part of the ignition switch or the fuel pump. It’s difficult to narrow this down too much without knowing if the problem is due to lack of spark or lack of fuel pressure.
yes ive already replaced the ignition moduel at the most 5 times and the fuel pump is also fine so the ignition switch is going to be the next thing i will try, thx 
I don’t know for sure on the Topaz but some Ford products of this era have the cabin blower motor wired through the ignition switch.
This means that high current (which is heat) is flowing through the switch. As the blower motor ages this means it draws even more electrical current and this can damage the ign. switch, which has a plastic housing.
If you get into this eye the plastic housing carefully for any burned areas or melted plastic. If this exists then the switch could very well be the cause of this problem.
I went through this twice on my old Mercury until I wired in a relay which allowed the blower motor current to bypass the switch.
Sorry I can’t be more precise here but I hope some of this helps.
thx 4 the info
by the way if anybody else does notice this question please reply, thanks