Frustrated with B@stard '89 Accord - Any suggestions?

I'll try to make this as brief as I can... A friend tell me he's selling his wife's '89 LXi. Needs cleaning up, but mechanically great - even has a new engine.

Well, I can detail cars with the best of them so I fork over my $1800 and think I'll either have a great car or make some money. After several days of work the car looks amazing. But then it starts to idle rough and the check engine light comes on. I go to look for the ECU and can't locate it. Hmmm... maybe I'll adjust the idle to see if that helps. Hmmm, again. No idle control valve or A/C idle boost valve.

I check the engine serial number and it's NOT a 2.0 L engine. It's a 1.8 with a Japanese code for a carb engine (A18A). The cars does have fuel injection, in case you're wondering, but I honestly can't find an ECU anywhere to check the CEL codes.

My friend said the shop that did the work is out of business, so I'm out of luck there. Other than at idle, it runs great and has ice cold a/c. Any suggestions on how to make this thing idle and/or tracking the trouble codes? The CEL resets after turning off the ignition, so I don't think it's anything major. Any help would be appreciated!

ecu located under driver seat, if you look from behind you should see light blinking (w/ ignition ON). blinks represent trouble codes.

Thanks! You're my hero. Six flashes... looks like ect trouble. At least I have some direction now. I've got a few shop manual references about testing the ect, but would appreciate suggestions on how to do it without plugging it into a Honda specific computer.

There are two sensors on the thermostat, but I've yet to find a diagram the specifies which one is the ect.

ECT is skinny one with just one wire coming out.
to test it you need to disconnect wire from sensor and grounded it, then turn ignition on and watch temperature gauge, it should go all way up.
if it did, you need to replace sensor.
if it did not, you got wiring problem and you to trace wire and find the problem.

The ECT is different than the temperature gauge sensor. The ECT sends a signal to the ECU which adjusts the mixture based on the temp. That's why my car's not idling well - I read that when the ECT sensor fails it tells the ECU the car is cold... and it floods the engine.

The shop manuals I've accessed say it's a two wire sensor on the thermostat housing. There are two sensors there that are very similar... however, I found one at an AutoZone near by and hopefully the plug will only fit one. Autozone claims they'll take it back if it wasn't the problem. It may be the quickest/most accurate way to solve the problem. The test procedure I found involves removing the sensor, heating it in water on a hot plate and charting the resistance against temperature. Unfortunately I don't have an appropriate thermometer and I'm still not 100% sure which sensor to test.

For the archives: Auto Zone promised me that if the new ECT didn't solve the problem they would take it back. There were two ECTs listed for the car - one in the thermostat and one in the cylinder head. The one my car needed was the one described as going in the cylinder head even though it looks to me that it mounted in the thermostat housing. Oh well... that one was cheaper and Auto Zone happily exchanged the first one I bought. Here's a hint... look down on the pins and put the tab that locks the plug onto the ECT at the 12 O'clock postion. Now look for the position of the raised guide. If it's at the 7 O'clock position then get the ECT described as going into the cylinder head.

No more CEL! No more stalling! $24 well spent!

Congratulation on solving the problem.