Crap! '93 Sentra SE idle acting weird again :(

[TomMonger]

I thought I was out of the woods, but apparently, I still have this problem. My '93 Sentra no longer stalls when coming to a stop (thank goodness!), which was my original problem for the past 3 summer. But here's what I've been faced with lately:

Get up in the morning, start my car, and she runs at about 1000-1100 for a few moments and gradually kicks down to 600-700. Flawless. I drive until engine is fully warmed/hot. Park. Let sit 1/2 hour to an hour. Try to start her up again, and the idle is like half-assed. The RMPs are up there, but the engine shakes and the car will hesitate for about a minute or two, and then she's fine. Reminds me of when I had a cracked distributor cap several years ago. If I let the car sit 2 or more hours, it starts up fine.

Here's what I've done so far in the past 3 weeks:

Replaced spark plugs (with NGK V-power)Replaced plug wires (which I *thought* was my problem, but apparently not)Replaced PCVReplaced fuel filterReplaced O2 sensorCleaned IACVCleaned MAF sensor (as best I could)Took off throttle position sensor and cleaned it up (and throttle area)

When it was idling crappy, I disconnected the IACV, and it was still running crappy. I did the same with the MAF sensor, and got the same result. Can I assume that these have nothing to do with the problem?

I'm out of ideas. It seems to be sensitive to the ambient temperature. We've been having really warm days here in NE Pennsylvania, which may or may not have something to do with this idle problem.

On a good note, I took a 370 mile trip last weekend and my car got 45 miles per gallon!!

Thanks for any help...-Tom in Scranton, PA USA

[RED_DET]

Well Tom, have you checked the voltages for the MAF ground and TPS voltages. Normally idle issues deal with either MAF related issues. I'm not a big fan of overpriced spark plugs, so I will ask the question, did this problem occur before the plug change?

[TomMonger]

I haven't checked any voltages yet. I suppose I can do this with a multimeter.

Yes, I had this problem before the plug change. At one point, the car ran awful full-time. So I wanted to double-check the plugs and distributor cap, and noticed one of my plug wires was bad, so I got a new set. When I put 'em on, the car stopped acting up. I thought the bad wires was the cause, but apparently it wasn't. The car may have gotten better because the air temp cooled down for a few days, and now its hot again. I dunno.

-T.