Hello i have a 1992 honda accord mt. It idles erratically after it warms up for a couple minutes but before it is completely warmed up. it jumps back and forth between 1200rpm to 1800rpm. Once it is totally warmed up and if i cut car off and then return to restart it then will idle normally.

 

The car is designed to idle higher when the car is started from a cold start. It will drop down as the car warms up. This is completely and totally normal.

 

You might be able to tighten the plunger inside the FITV; there's a thread about that in the DIY area. Then you can look at all the other things that can cause a surging idle, listed in a post by me about setting the "BASE idle".

That is, if the idle surges during warmup. If it idles high then smoothly decreases as it warms up, that's normal like holmesnmanny says.

 

thats not what it does. Before it gets warm it will idle erratically between 1200 to 1800. JUmping back and forth until u cut engine off after it is warm. Once u cut off engine once it is warmed up then it will idle correctly. Of course i know it is suppose to idle higher when it is cold.

 

Suggest, as Jim has, cleaning and adjusting the FITV as a start. There is also a boost valve on the drivers end of the TB that you can clean if the first doesn't solve it.

 

The cool thing about the '92 is that with the location of the FITV, you can do it while the engine is running and get it to just barely close the FITV plunger to get it to normal without potentially losing cold start rpms.