My '95 945 Turbo has 147,000 miles and run great, except that several weeks ago the engine just stopped on my way to work with no warning, just like I turned off the key. While trying to merge right to the shoulder I tried restarting and after several tries it started. I continued on to work, but at a much slower pace in the slow lane (average traffic speed on the freeway to work is 75 to 80). This continued to happen with increasing frequency so I consulted the FAQ and found two possible causes, RPM/Reference Sensor and Ignition Module (both have several other names). I ordered both along with a distributor cap, rotor and spark plugs.

I replaced the RPM/Reference Sensor and Ignition Module as soon as they arrived and the problem went away for two days, then it returned allowing me to drive only a few blocks before shutting off. I called fcpgroton.com and ordered a replacement Ignition Module. I installed it along with the distributor cap, rotor and spark plugs and the car ran great for a week. This morning on the way to work the engine stopped again.

Could the second Ignition Module have failed? Should I have purchased the Bosch unit? Is there a way to test it? I felt certain that it was the problem because after replacing it the car runs great.

Thanks in advance for you help.