Thanks Redbull-1, I plan to pull the engine harness out of the car from C131 and open it up hopefully late this week or early next week and take a close look at it. I'll keep posting until I finish it and Thanks again to everyone on here.
Pondrun

 

Before pulling the engine harness out, take a look at the Brn/Blk wire connection and terminals at pin 2 of Connector C131. That is part of the grounding wire for the shielding.

 

I hope I'm replying properly to my own post, if not please overlook me.
Today I was able to get back on my car after weeks of not looking at it. I learned something today that puzzled me.
I measured the cranking voltage at the output of the Crank Position sensor and the top dead center positioning sensor. Both sensors measured about 125mv ac while cranking which I consider to be normal. I then re-connected C124 and measured these same voltages at C131, which is the bulkhead connector leading to the computer.
Please note the following.
For some reason the voltage output on c124 went from 125mv at c124 to 1.8v ac at c131 on the crank position sensor line
Any Idea's?
Danny

 

Don't apologize for anything. You've been very polite and gracious on this forum. Go ahead and post, as many times writing things out and thinking about the logic of things will turn into a resolution.

I am not sure what those results means.

Here are what some of the other wires at connector C131 are. I could not find whether pin 3 has a wire or not.

C131 – 14P gray
1 – Yel/Grn (Engine Coolant Temperature Gauge)
2 - Brn/Blk (Ground wire for shields)
4 – Blk (Ground G101 wire)
5 – Yel (CYP sensor input - PCM )
6 – Grn (TDC sensor input - PCM)
7 – Blu (CKP sensor input - PCM)
8 – Red/Wht (ECT sensor input – PCM)
9 – Blk (CYP sensor ground - PCM )
10 – Red (TDC sensor ground – PCM)
11 - Wht (CKP sensor ground – PCM)
12 – Grn/Blk (AT Lock-up Control Solenoid B valve control – PCM)
13 – Yel (AT Lock-up Control Solenoid A valve control – PCM)
14 – Wht/Grn (Engine Coolant Temperature Switch B Input – Radiator Fan Control Module)

 

Thanks Redbull I checked for continuity from pin 2 to G101, which is on the intake plenum and it measured .3 ohms. I don't know if the excess voltage on the Crank pos. pin is harmful and I don't know how it's getting there. Usually the shielding only works when there is a lot of things happening to prevent radio waves from triggering the computer. That voltage has to be getting on there by leakage somehow but it is only on there when cranking and not there when the engine is at rest with the key on. I know the computer take the low ac voltage generated by the crank sensor and makes a 5 volt square wave out of it to fire the ignition. I need to pick up a scope and look at the computer output to see if it is a 5vdc square wave. Thanks for everyone's help. I can only work on this every once in awhile but I am getting close to my wits end. Danny

 

Troubleshooting a CYP problem, I ran across this page:
...showing O-scope waveforms for that sensor's output. I imagine the waveforms for CKP and TDC are similar.

Thinking out loud, have you tried starting the car with the alternator unplugged? AC voltage spikes from a bad alternator diode overwhelming the tiny CKP output?

 

Roader, that is a brilliant suggestion about the Alternator, I will try it an let you know....... Danny

 

On 98-02 L4 Accords, faulty diodes in the alternator were known sometimes to cause electrical interference to set a P1381 trouble code.

https://www.hondaaccordforum.com/for...ow-test-55792/

 

I pulled the connecters off of the alternator yesterday to see if I was having problems with the alternator and the car did start. It starts occasionally, It starts more often if I keep the battery tender on it and keep the battery hot, it just spins faster. The car missed between 2800-3000 rpm and would not run faster than 3Krpm's, the car actually starts idling slower and slower until it stalls out and dies. Its done this since this problem started. If I clear the fault codes while the engine is running the engine dies immediately. I'm still seeing 1.8 Volts AC at pin 7 and 11 on C131 Which is the output for the cranks sensor. which is about 1.7 volts AC to high, I think.
Has anyone ever measured the voltages on theirs, if so, what did yours measure?
Danny

 

I have no idea. The link above indicates that the CYP AC output is:
Different sensor obviously but:Where are you getting that spec? I've never run across AC voltage output spec's in the FSM, only resistance.

Just curious.