Rpm spike I have a 1993 nissan altima. The car starts fine and idles fine on the initial start but once it warms up the rpm's will spike down from about 1000 rpm's to 500 and when it does you can feel i big drop in power! It also does this after you drive for a while and then come to a stop at a red light! Can you tell me what the problem is?

SOURCE: Idle problem

Yes you can,

do this with your RPM setting,

you ahve to just set you engine race settings,

try & having funn with your car,

THNX

SOURCE: 2000 Nissan Altima temperature gauge and heater problem

sounds like you need to replace the thermostat.

SOURCE: when engine is warmed up the car begins hesitating

check your engine vacuum pull off a line near you egr port ..egrs get clogged as well ...test your vacuum you need to be steady close reading near 14in hg
next your oxy sensor could be working but slow leaning out your injectors and also understand that a voltmeter can test your sensors now do not forget about plenum or intake leaks ...if your car has an idle control valve it can be malfunctioning i usually only see them go bad in cadillacs though..

SOURCE: 2000 nissan xterra hesitating when engine is warm

We are having the same problem. We are right now changing the crankshaft position sensor along with the intake and manifold gaskets.

SOURCE: when engine is warmed up the car begins hesitating

I really think it's the TPS, (throttle positioning sensor) on the throttle body. When this sensor is defective or out of position the vehicle will idle like that and even stall. If you haven't had it scanned, you should do so, that will probably tell you the problem.