The ECT sensor reports the coolant temperature to the ECU. The ECU uses this to find out if the engine is cold in which case it adds more fuel, which would help the engine warm up faster. The ECT sensor is also used to adjust spark, EGR function, open/closed loop feedback, idle speed and so on...

 

Here's an excellent post regarding open/close loop:

Honda-Tech - View Single Post - Why can't a car always be in Closed loop mode?

 

ok well I havn't been able to test out a cold start, however I have replaced the ECT, but after resetting the ecu (both from pulling the fuse, and disconnecting the battery) it still flagged code 6 :/

 

do you have a volt meter?
have you downloaded the service manual from the DIY section of this forum?
pages 231-232 cover the testing procedures for the ECT
It is pretty simple

 

wait I was looking at the 94-97 manual, I do not have the 90-93 manual.

I think Poorman knows more about those than I do.

Hopefully he sees this thread and chimes in.

 

I don't remember where I got if from, but I was able to DL a manual for the 91 accord.
it says that the sensor should read ~200 Ohms, and the wire should be about 5V... both are good...

 

next step is to swap ECU for a known good one.

 

did you test for the +5 volts between both wires or just from the red/white to ground?

 

After an engine swap, double check the wiring. Isn't there another sensor with the same plug as the ECT? Like maybe the plugs are swapped with the throttle-position sensor?

 

any recommendations for where to go? a while ago I was refered to car-part.com are they good?

I checked between the wires... I thought the other wire was ground?!?!

ya there's 3 plugs almost exactly the same... it took me a while to find the 3rd but there's the ECT(below distributor), one on the upper radiator return hose(actually a housing attached to the head that the hose connects to), and one on the thermostat housing(within reach of being mixed up with the ECT plug)...
I checked to make sure it was hooked up correctly(I even tried switching with the thermostat plug just in case) then verified by wire colors