Car stalls out, rather than idles

[annointed]

Unfortunately, I feel like all I'm doing in here is complaining about problems, so I apologize. I just purchased an NSX that has an absolutely gorgeous exterior, but has its share of problems that the seller asserts didn't exist when the car was in his possession

Anyway, today a new problem reared its ugly head. It was raining pretty hard, and my NSX stalled out 4 times when it should have just settled at idle. I'd coast to a stop light, slip the car out of 2nd, and then, the car would just let the RPM's drop too low, and conk out. It would always start back up, but after it refused to hold an idle, I became paranoid that it might not start up after one of the stall-outs, and I had to manually hold the idle up around 1k rpm after restarting.

Later that day (5 hours later to be exact), after the rain had pretty much stopped, I was on the way to another client, and as I let off the gas and slipped it into neutral in front of his house, the car just died out again. The rest of the day, as I drove from client to client, I'd notice the RPMs dip to 300-400, then the car would manage to catch its idle w/o stalling out. Also, upon starting, the idle would surge, then dip too low, then surge, then dip, then find a stable point. I don't recall the idle behaving this way earlier. Is there any connection between the rain/humidity today and this idle problem? I've also had the defrost on most of the day, which I haven't done since owning the car on Wed... Or are there any likely causes of such a problem as this?

Thanks for your insight. This community of owners is an amazing support vehicle, and I appreciate the help I've already recieved with other issues that this car has.

 

[annointed]

Oh, and btw, this car has high milage (122k miles on it), and another member here already advised me that he resolved a similar problem on his
95 NSX-T by cleaning out his throttle body. I suppose I'll start there, and see what happens. Does the NSX have any kind of idle air controller or fast idle valve?

Thanks.

 

[latzke]

The rain might be correlated...

http://www.nsxprime.com/forums/showthread.php?t=67665

 

[Doc308]

You can check the coil covers to insure that they are not installed improperly. Specifically, there is a rubber gasket on the inside of each one and the covers are supposed to be mounted with the gaskets on top of the coils. If the front and rear covers are mounted on the wrong sides, the gaskets will be on the bottom potion of the covers and water can then leak into the coil/spark plug holes, making for poor performance. Remove the covers. coils, and plugs and check for water/dampness .If wet, check the plugs carefully for fouling, glazing, and cracks. Of course, there may be something else wrong, but if there is a clear correlation between the rain and the problem, I'd start here and , if this is OK, look for other components getting wet somewhere. It is feasible that the previous owner wouldn't have experienced the problem if he/she didn't drive the car in the rain --if this is the problem.