Loss of Power - No Codes

[TownCar97Exec]

About 3 months ago I bought a 1997 Towncar Signature. Had no problem throughout the Texas summer but over the last two weeks I seem to be getting a problem when the car is warmed up / running for about 30 minutes.

When the engine is hot and I am in drive, the car goes into a “limp mode” like state. No codes with the odb2 and I loose all acceleration and engine power. Even with my foot to the floor the car will go from 65mph on the highway all the way down to 10mph and sometimes even cut out.

If the car shifted into neutral the accelerator works and the engine will rev. Also works when stopped and in park. But as soon as I try to accelerate in D, 1, or 2. The problem occurs again.

Already tried replacing the TPS. No luck with that. Has anyone experienced this before?

Thanks!

 

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Has anyone experienced this before?

No.

And with no codes, the issue should not be an electronic engine control part. If it were, then a code would be generated. So do not throw electronic parts at the problem.

Look for something that is non-electronic. Suggestions would be ...
Fuel filter - since you have owned for 3 months not a lot of known history. I would change it. And note the old fuel that is left in the filter. Pour out on to a white piece of paper.
To a lesser degree, the air filter.
Battery - have this load tested to make sure it is healthy. As a side note, looking at battery cable ends and condition. Clean as needed.
Charging system - with a warmed up engine and engine on, battery voltage should be 13+ volts. Engine RPM in the 1500/2000 range, the voltage should be 14+
Exhaust system - this can be diagnosed with a vacuum gauge. If the system is restricted, the vacuum gauge will slowly drop when engine is idling. Not highly likely and something to check anyway.

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