the car is a 93 hatchback with a d15b7. it has a problem with the idle. it surges up and down when it gets to operating temp. i am in the process of trying to locate that problem and i found a problem with the air temp sensor. i pulled the old one out and the prong that goes into the manifold was burnt and melted. so i replaced it with a new one and let the car idle and reach operating temp, idle problem was still there. so, i took the new air temp sensor out to inspect it and it was also burnt and melted. what could be causing this?

 

post a pic of the sensor, for the surging idle check these:

-coolant level, if you are low you could have a leak causing air in the system making the idle up and down
-clean IACV (in the FAQs there is a write up)
-clean FITV (also a write up in the FAQ's)

 

fixed the jumpy idle. replaced the iacv with a used one and problem solved. i am gonna check the wiring for the temp sensor to see if that is the reason why it is burning up.

 

What wire colors do you have at your IAT and IACV connectors?

If you're IAT is getting burnt up, chances are you have the two switched, as they use the same style connector.

IACV - blue, yellow/black
IAT - red/yellow, green/black

 

Evap purge is also commonly swapped with IAT as well. I think the wire colors are yellow/black and red.