Since the PCM detects the CKP/TDC sensors signal interruption, part of this sounds like the PCM going into pre-programmed limp mode, which ignores inputs from engine sensors.

 

These sensors use a round looking gear with teeth on it, mounted on the crankshaft of the car to generate a low voltage ac signal. When the gear rotates past the sensor it creates a change in the magnetic field of the sensor and thus generates a voltage, much like the coil and flywheel on a small engine. The computer takes that voltage, amplifies it and makes a square wave out of it to fire your plugs. Pondrun

 

Where did you get that spec? Is it possible that the ECU is looking for a larger cranking value, perhaps 500 or 750mV, and if it doesn't see it then the engine won't start?

 

I haven't fully researched the in/outs of doing it; but, searching through the web, sounds like there's the possibility of adding a pull-up resistor to condition the line signal.

 

The engine dies when I clear the fault codes out. Is this normal?
Next week I hope to have time to work on it as I've not had much time lately. I may look at pulling the engine wiring harness out and checking it out thoroughly. I'm really confused why there is 1.8 volts on the Crankshaft sensor but only .080 volts on the top dead center position sensor when both sensors are the same. I'm getting my fault off the the sensor with the 1.8vac on it.
Pondrun

 

I thought you were getting both P0336 and P1361?

I have a feeling that 1.8VAC is the right value; 0.125VAC (or 0.8VAC, depending on the post) is too low. I don't know this for a fact. The only evidence I have are web pages I've found when fighting a CYP CEL. For instance, this page shows TDC scope waveforms for a slightly older, five cylinder Honda (channel 2):


Are the voltage and resistance measurements being taken at the connector next to the upper timing cover, at the ECU plug, or at some intermediate connector? Since you had the problem before, and swapped out the CKP/TDC sensors, I think Redbull is right: there's a wiring problem.

You've done everything right, IMHO, and still have the problem. My gut tells me that the sensor measuring 0.125VAC (or 0.8VAC) has a partial and intermittent short in the wiring somewhere between that sensor and the ECU.

 

Thanks again to all for helping. The car has now been disabled for 3 months and I will have time next week to put a bunch of time in it.


I am getting both fault, the only one though that has shown up for a few weeks though is the 0336 so I've only been mentioning this one.
The voltage measurements were taken at C124 ( back corner of Valve cover ) then that connecter was re-plugged and C131 was disconnected at the passenger shock tower. There I notice the increase in the voltage on the Crank sensor and the decrease in voltage in the TDC sensor. I've taken all resistive measurements from the sensors all the way back to the ECU and they never changed. They measure 2100 ohms (about ) on both sensors. The voltage measurements were taken while cranking the car. I currently have the 2nd ECU on it and it does the same as the original ECU.


When I do get it started and while the engine is running and erase the fault code it always dies. Is this normal on these cars?
Thanks so much

 

I took a look at the link you provided. On that car the sensors had to be Hall effect sensors in order to generate that kind of voltage. The sensors on my car are pretty much just a magnet that generates a small voltage. Somewhere on the internet I read that these would only generate below 100 mvac, which is about what mine produce.


Pondrun

 

I thought Hall effect sensors were all three-wire, with the third lead for the power supply, and have internal circuitry to output square waves. Versus variable reluctance sensors which are two-wire, generating sine or triangle waves, with the ECU providing signal processing. From what I've read (not practical experience!), variable reluctance sensors generate 2VAC peak-to-peak minimum. A DVM would measure ~0.7VAC: peak * 0.707.

Again, I haven't seen this with my own eyes. I've been chasing a wildly intermittent DTC 9, a CEL that won't show up for six months in warm weather but seems to pop up once a month or so in cold weather. But I've been too lazy to get my scope out to check the waveform.

 

I've had time to work on the car lately. I pulled the engine harness out of it and went thru it wire by wire using the factory wiring manual. I found no problems anywhere. I also did parallel measurements on the stock and junk yard replacement computer and found no differences. Today I put the harness back in the car and I purchased another computer off ebay yesterday that I intend to try. After this I must admit I'm lost. This has been the best car I've ever owned and enjoy driving it. At this point it has cost me so much time that I'm at a cross road of what to do with it. Hoping the computer fixes it. Thanks for all your help
Danny