[V8] 1993 V8 - will not idle properly

[W]

I have a 1993 V8, 180,000 miles, in very, very good condition. Two days ago
it suddenly started idling high as if the engine has a mind of its own. The
idle will go from 1100 rpm to 2800 on its own. Consequently it cannot be
driven given the erratic behavior.  Have started it several times and on
occasion the idle will return to normal then suddenly go erratic again.
Wondering what could cause this and a possible solution. The fuel pressure
regulator is 5 yrs old. The ISV is a year old. The O2 sensor in 3 months.
New cats, 1 year. The two speed sensors are a year old. The coolant temp
sensor is 4 months old.  The MAF sensor is a year old. The TPS is 3 months
old. What could be the issue?

 

Thanks

Allan

Washington DC

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