I had a similar problem on 94EX; CKP sensor error and went same route as you w/ replacement distributor which did not fix the problem. After checking resistance of sensor at distributor, fender, and finally at ECU w/ same values all three locations, I decided the ECU must be source of the fault. BTW, my fault was continuous so yours may be more difficult to check and confirm.
I would suggest getting someone to shake/push wires while you observe resistance of the sensor at the ECU connector.

You will need a good shop manual (Honda) to get the correct pins to monitor sensor resistance. You could download the 94-97 Accord manual from this site, which may be similar (but may not). Check ebay and helminc sites for a hard copy or soft copy manual.

Used ECU's are readily availalbe at reasonable prices. Check car-part.com or ebay.

good luck

 

Alright heres the latest. To answer JimBlakes alt questions.

Voltage after sitting over night - 12.46
Engine off with lights and ac running - 11.63
Voltage during starting of engine - 10.9 then back to 14 after it turned over
At warm idle no accessories - 14.45
At warm idle with all accessories - lowest was 12.5 and back up to 13

I also checked the resistance of the sensor on the new distributor. It came out around 860 as compaired to 750 before i changed it. I also traced the wires back to the ecu and i still had the same resistance there and no continuity to ground from the yellow wire. Everything checks out. So again, im lost.

 

Here is a Honda Service News regarding troubleshooting tips for P1381, mentioning the Accord 4 cylinders. If you can't find any other things wrong, it can be the ignition coil shield in the distributor or the alternator diodes.


tegger.com/hondafaq/p0420/A050900.pdf

 

If the Accord is a 4 cylinder, it may already have a Denso alternator.

Most of the Delphi alternators had that tell-tale black end cover. Here is a link showing the Delphi in a V6:

diymyhonda.com/accord/v6-alternator-upgrade/

 

I gotta doubt the coil shield since the distributor is new. So is the coil. Not sure if i wanna go out and get an alt with my fingers crossed but i dont know what else ta do.

 

The Honda Service News states:

Unplug the 4P connector from the alternator

3. Test-drive the vehicle.
• If DTC P1381 comes back with the alternator unplugged, replace the distributor housing.
• If DTC P1381 doesn’t come back, go to step 4.

4. Plug the 4P connector into the alternator, and use the HDS to do a charging system test. Look at the alternator diode pattern on the display
screen.
• If the diode pattern doesn’t look right, replace the alternator. A faulty diode can cause electrical interference that sets this DTC.
• If the diode pattern looks OK, press on with normal troubleshooting.

You wouldn't have the Honda Diagnostic System (HDS) equipment and software. But, I am not sure whether you want to try unplugging the 4P connector from the alternator to see if the trouble code remains. Many times, it takes 2 consecutive drive cycles with a fault for the Check Engine Light to come on; but, if a fault in detected within one drive cycle, a pending code may be stored without the Check Engine Light on yet and the code can be read.

 

Idling with a lot of electrical loads, it's 12.5 to 13 volts. Lower than the 14 I'd expect, but I'm not sure that's low enough to suspect a blown diode (in the rectifier bridge inside the alternator).

To avoid throwing parts at it, I'd go someplace like AutoZone & have them test the alternator. I think(?) they can put it on an oscilloscope to see if the output is very choppy like it would be with a blown diode.

Don't suppose you have an oscilloscope... ?

 

I could try the unplugging the connector at the alt. And no i dont have an oscilloscope. Ill call around and see if i can find someone that can run that test for me/ check out the alt. Thanks for all the help u guys. I appreciate it.

 

Ok so theres been a new revolation in the issue. When i traced the wires i dissconected them from the ecu and after all was said and done the code had cleared. I told my wife ta keep a close eye on the car. Tonight on her way home she went to roll up both the back windows at the same time and when she did this she says the all the lights dimmed and the cel immediatly came on.

I know that sometimes the instrument gauges will dim in my car when i roll up the windows but she said everything dimmed and then the cel came on. I scanned it again and its the same code. Is this a sign that its linked to the alt?

 

Get the latest trouble code. If it come back with P1831... hmmm... electrical interference from an alternator with faulty diodes and some charging problems under load?