My d4 light always blinks. The transmission shifts fine. When the car is warm and I'm in park of neatral the idle goes up and down from 1000rpm to 1500rpm. the check engine light is on. Any suggestions on what is going on would be greatly appreciated.

 

What year accord are we talking about here?

 

It's a 94 ex

 

Suggest you start by getting the codes, see the Common DIY Threads sticky at the top of this section for a "how to". Be sure to get all codes (D4 and CEL), post what you find and please note which code came from where.

The idle, sounds like low coolant, air in coolant or a dirty IAC but lets start with the codes.

 

the CEL gave me #6, and the D4 didn't give any codes when I shorted it

 

Suggest adding your car info to your signature so you don't forget to add it.


OBD-I code six from the cel is for the ECT, two wire sensor directly under the dist......

 

that what my car was just doing too. Its a pretty easy fix. First check the plug to make sure its got good connections. If that parts good then youll just need to replace it. I couldnt find a way to get it off without taking the distributor off, but it wasn't too hard/

 

I replaced the sensor and the check engine light went away as well as the D4. thankyou for your help. the idle problem is not as bad, but could still use work I've read that bleeding the coolant system sometimes fixes it, I'll try that.

 

Be sure the coolant is full, then try the bleeding. If that doesn't help, read about cleaning the IACV