95 Taurus, many parts replaced, ignition issue

[UTSARacer]

Ok, I have a '95 Taurus (ok, well, its a Sable, but I won't tell if you don't) that has a fun problem. It starts and runs fine, but once it got hot the spark gets weak and eventually the motor dies. I have checked the spark and when the motor starts boging and dieing off the spark is definalty the issue. I have changed the modul and put in a new coil and have done all the coil diagnostics and all have checked out ok. My question is, does this sound like a distributor replacement issue or is it something I'm missing? It it is distributor what is bad in it that is causing this? Thanks!

[ABE]

Do you have the 3.0 or 3.8 engine? Is your check engine light coming on?

When the engine gets hot and the spark fails, is there "no" spark or a "poor quality" spark (weak and yellow rather than fat and blue)? Did it have the same problem before the module and coil were replaced? Are you sure the new components are good? What is the primary and secondary resistance of your new coil?

Someone on the board had no spark at all and that turned out to be a worn out distributor not meshing with the camshaft. Distributor cap and rotor are replaceable and can fail due to cracks and metal erosion from rotor to cap contacts, but it is usually misfiring on some cylinders.

Plug wires deteriorate over time and need to be replaced. Spark plugs also get worn out and need replacement. Usually misfiring though, except for the coil to distributor wire that could give your symptoms.

Have you tested your compression?

[UTSARacer]

It's a 3.0, and the test light comes on sometimes, sometimes not. We have replaced, literally, everything under the hood. Dist (cap and rotor also), module, O-2 sensors, ECU, coil, coil capacitor, all sensors... and on and on. I bought the car with the issue and was told it had just started randomnly. The car starts and will run PERFECT, even drive PERFECT, for 10 to 15 minutes, then it will start to lose spark, I have checked the fuel pressure, it is perfect in all cases, I have also looked at the spark (holding a plug against a ground with a wire on it while the engine was running), when the problem starts to occure the fat blue steady spark becomes a weak, light blue, eradic spark. I had it on a scan machine today and it reported no 0-2 sensor on bank 1, out of range reading on bank 2, lean condition and out of range reading on the water temp sensor. Replaced both 0-2s and the water temp sensor, no change. Tommorow it goes to a professional shop and if they cant fix it this low miles, pristine Mercury Sable may meet its maker, help it live!

[ABE]

All the electricity to run your ignition will be routed through your ignition switch and related relays. Sounds like you have a high resistance in one of the circuits that is causing overheating of a component leading to failure. Check your ignition switch as the most likely culprit.

You may also have a grounding problem causing poor sensor input to the EEC-1V. There are a lot of grounds so look for the ones related to the EEC-1V computer, engine and body. I think there is a pink/orange wire on the EEC-1V connector for ground that connects to a black/white ground wire and the VSS (Vehicle speed sensor).

On my '93 3.8 the computer is located in the passenger compartment on passenger side below dash by right fender. There is a braided ground strap in the engine compartment on the right side near firewall connecting body to engine. Battery grounds to engine at the starter mounting bolt. Check the firewall for grounds and clean them up.

I have heard several people report much improved engine performance after working on improving their grounds. That is all their grounds - takes a while.