I recently started noticing that when I put the car in P it doesn't idle normal, instead it starts to accelerate uu and down by itslef, It was happening only when in P, but now when I'm driving the car and I let go of the gas pedal for a moment, it will do it sometimes too. I have already cleaned the Idle control valve with spray cleaner, it didn't do much, Today I went to get a new ($250) Idle control valve, put it in, had to buy 2 feet of hose to replace the original 2 hoses which were pretty much melted and toasty and when It was all said and done, it did the same exact thing.

Related problems: I don't know if this is related, since last night the car also also revs to number 3, and i Hear the engine making noise to work harder, but I'm only going about 15-20 miles an hour and it wouldn't shift like normal, a problem I've been having with the cra is that the D4 light blinks sometimes, I'm about to take out 2 quaters of tranny oil and add some Lucas tranny fluid for slippage.
Any suggestions I'd appreciate, I'm not an extremely good mechanic but at times I can hold my own.

 

Also check/clean the FITV. Look for a thread on that, or search for "FITV".