]So the weather is getting hot now and it did the same thing last year.

The car would never die, but say when I come to a red light, it would idle at around 100rpm to 300rpm. Then sometimes it wouldnt start unless I let it cool off for a good 20min. Last year i changed the main relay, cleaned the EGR, TB and IACV. Seemed to work for the rest of the summer.

Now lately, its doing it again, but not as bad. Im going to change the dizzy cap and rotor and see if it helps, since I have the parts from Honda sitting at home.

What would cause this?

 

Try cleaning the FITV, it also effects the idle. Its like the choke on a lawnmower for our cars. Without one they have trouble starting in the cold. If its not working as it should may cause issues once warmed up.

You can delete them, my PRO S2 TB doesnt have a place for one. You just have to loop the coolant lines, and fab up a block off plate.

Its not the most common issue, but couldnt hurt to check it.

Also calibrating the TPS couldnt hurt if not done already, effects idle as well.

Then the obvious ignition timing, dont forget to jump the service plug too.

 

the TPS is fine i believe because it only does this when hot.

ill try everything else
thanks mang

 

It's physically impossible for the car to idle lower than 300 and not die. The tachometer, unless you have an aftermarket, won't even go that low.

The first big line after 0 on the tach is 500 not 200.

The oxygen sensor has most of the control over a warmed up car's idle.

 

Personally, I would check out both the FITV and IACV, as they both have the coolant lines running to them, and are physically affected by the engine getting warm.