please help

[jat2304]

i need help with my 91 240sx ka24de. When i run it hard and then stop at a light my idle goes up and down sometimes when i have to stop suddenly it will go all the way down to 200rpm's and shut off the engine . also when i and driving around 2500 to 4500rpm's it feels sluggish and kind of speeds up after 3500 to 4500rpms . any help would be great thanks!!!!

[Axel Grungy]

i had the same problem, check your coolant temperature sensor connection. its probably all corroded and nasty, clean it up and should be good, it cured mine

[Ni2s4s0aSnX]

Yeah, its most likely some sort of sensor problem. Or it might have to do with the actual coolant system itself. Or maybe you need to change the PCV valve. When was the last time you did either of those things?

[mr_wizard]

does it do it all the time... or before or after being warmed up

[jat2304]

for the most part, after it has warmed up. since i the other day, i have checked and set my tps as well as set the timing to specs. the tps reads 2.0 ohms closed about 4.7 at half way, and 9.2 wide open. my timing is right at or about 20 degrees