I'm having a CEL 4 - CKP issue ...

And two new Richporter Technology distributor hasn't fix it ...

Bench tested the distributor, all three signals are good ... Looks like signals below:



But once the distributor is installed, the crank signal has a sine waveform and a random spike and flats when the engine is running and even during cranking. (CEL 4 pops up on neptune after a few seconds.)

The signals are scoped at two location with the same result: Right before the ECU and at the distributor harness with a Snap On Modis.

But ...

If I take out the distributor and spin it with a drill, distributor harness is still connected, and key is on so ecu is on, the crank signal is a clean sin wave.

If I take out the distributor and spin it with a drill, distributor harness is still connected, and cranking the engine at the same time, the crank signal is a clean sin wave.

Disconnected coil/ignitor power harness, no difference ...

Spark plug wires connected or un-connected, no difference ...

Distributor housing touching cylinder head for ground vs touching chassis for grounding ... no difference.

The car has stiff valve springs and there is a tiny cam kick back when rotating the engine by hand.

Has anyone encounter this problem before? Stiff valve springs maybe kicking back and causing the distributor to rotate backwards a msec and then forward again, creating a bad waveform. But I'm pretty sure hundreds of Hondas have stiff valve spring and using OBD 1 ecu without an issue.

I can't think of anything else. Tried 4 difference chipped ECU when I was think it was an ECU issue, same thing.

Car: 88 Integra, Converted to OBD 1 ECU, Chipped and using neptune to tune it.

 

If you have it bolted on to the engine and its not getting the correct signal but when you take it off and its getting the correct signal its called NOISE. You can try two things, get better shielding wire or try filtering the signal.

 

Has it always thrown that code or did it come with the OBD1 ECU swap? What distributor are you using?

 

I agree with this guy. You should just buy some shielded wire and rewire it yourself straight to the ecu.

 

Needs more info before doing all that. Like are you even using an OBD1 distributor? Can't use OBD0 on an OBD1 ECU. Also check the distributor adapter if so for correct wiring. Also if you got your ecu adapter harness off eBay check out this thread:
http://hondaville.com/honda/threads/...-mode-RESOLVED

 

What is causing the noise?

As you can tell from my tests, I tried to isolate the noise ... I grounded the distributor housing to the head and chassis and there is no different. The noise only comes up when the distributor is being turned by the cam shaft and no noise if it's turned by a drill with everything else being the same.

Which is why I suspect the cam shaft kickback being the possible problem.

I probed right before the ECU which has the factory shield wiring.

As for a filter, I don't think you can. It has a good sin wave and then scattered signal ... good sin wave then scattered signal. I will try to get a screen shot this week.

Originally, it was on an OBD0 chipped ECU but I couldn't get the data logging to work. Turboedit + some viewer. The owner searched and tried for days and he gave up so I suggested swapping over to an OBD 1 ECU setup. So an adapter harness, OBD1 chipped ECU, and new OBD1 distributor. He couldn't get it to run so I took over.

ebay ODB0 to ODB1 harness - A few wires were pinged wrong so I went thru it and corrected the placement. Using schematics I found on AllData, forums, manuals. I checked the harness over a few times because of the error until I found noise in the signal.

distributor harness - Something I built from an OBD0 and OBD1 pigtails since he couldn't find an adapter. It has a separate cylinder pickup on the exhaust cam.

I don't think that's the problem. If the signal was dirty the whole time, I would have re-wired it but it's clean for a couple sin wave then dirty and clean for a couple of complete sin wave and then dirty. I will try to get a picture of it later this week.

 

Its a wiring issue. I am getting this phantom code as well for on an OBD1-0 conversion and even before the conversion. I know the shield wire is shot and I am positive the ECU is not being properly grounded. The main cause could be bad grounds for the ECU and I am certain 99% of the people will say that grounds is not the case and overlook it. (Which is most likely the case)