SPIKE'S91CIVICSI

So my 90 si started doin dat annoying idle going up and down about 2 months ago.its a y7 with a6 intake manny by the way.I swapped out the tps from a 98 civic and it wrked fine jus check engine light came on.so I went to junkyard again and took the whole throttle body of a crx si and swapped it.car started doin it again. Could it be something else besides tps?

jdm_rb20

If you have a code (while using a OEM tps sensor), then use the FSM troubleshooting guide. Also, make sure it is calibrated correctly.

Once that is all proper, then google "Honda Idle Troubleshooting" and follow the steps to inspect/adjust/clean the idle components.

acmoc

take off the idle air control valve and spray it with carb cleaner, let it sit for a day and reinstall
Did you bleed the coolant?
There is also a little scrw on top of the TB, screw it in a little bit to get rid of lopey idle, screwing it in will lower the idle speed so you have to tighten up the throttle cable as well or open up the TB butter fly a bit

BIG_Mikeeeee

Check all of your vacuum lines. It is possible one of the hoses has a leak.

DeadCatPuppet

I had the same problem with my 89 dx. Cleaned the IAC and it stopped hunting

91GEDHATCH

Make sure you have all your vacuum routing correct. Check IAC.

SPIKE'S91CIVICSI

Thanks guys! I will check all this stuff this weekend been busy doin gay army stuff...