Ah, pics are working for me now. Must’ve been an issue on my end.

Didn’t realize you had those circuits isolated and shielded too. Yeah, my insight is probably null. Very interested to see what you find on it, though.

Looks like a killer trip overall, though! Appreciate the in depth write up and all the photos. I gotta get out to CO this summer…

 

I assume you have looked at all the connectors and wire terminations for looseness? Earth? We had someone who had the cam sensor problem intermittently, tracked (eventually) to looseness between the connector and sensor - cable tie was the solution .

(No problem with pictures)

Geeze, you do do things in style - the motor home, TWO cars in the trailer, and the dog! , much envy!

 

Yup, checked at the sensor end, to the point of de-pinning the connector to check the wire crimps. The only thing I have yet to check is the pin on the ECU side at the ECU harness connection.

 

Thanks, guys!

It's an awesome setup for what we like doing, but it's not quite as baller as all that. The motorhome is 20 years old and cost us about the same as a decked out new crew cab dually. Still a lot of money, but nothing like a new one... Ours was clearly well cared for, and only had 67,000 miles when we bought it. And the nice thing about the older, high-end RVs is they're put together a LOT better than most of the new RV stuff on the market. Real wood, real tile.... etc. I had to search a LONG time to find the trailer... it took about 8 months to find a used stacker within reasonable driving distance. We have a LOT less in the whole package than new Sprinter based RVs sell for, for example.

I would have preferred something a little smaller, because it is a little exciting to drive in tight quarters. The big issue for us was being able to tow a stacker, and that required a chassis with some stones, and you don't find the big motors in small RVs. I originally wanted a semi-based Super C, but they are a LOT more expensive than the equivalent age/mileage Class A. If we're not racing, and just flat towing our Grand Cherokee, it's a lot easier to deal with, but we're still too big for National Park, and most National Forest campgrounds. But it's also big enough to be comfortable living in for a month at a time, so we make it work.

And you gotta love modern technology... streaming F1 in the Paddock...

 

Roda's RV+tow setup is super nice, saw it in person, very impressive. I do agree that piloting that thing makes me nervous, but if you keep it on main highways probably not too bad at all. I'd avoid the million dollar highway with that rig, for example, though.

And 63.8 on BP power is hella impressive. I'm sad the car wasn't working because now I'm super curious what it will do on the K. I guess we'll find out next year!! I know there's at least 61's on the table for my car, especially watching my videos after the fact, so I look forward to making it back to GJMS!

Hopefully you get the issue sorted, maybe we can plan a fall trip to ASR in Las Cruces?

 

Can you check the gap on the factory sensor? It'll require some depth gauge trickery, and then subtracting the length of the OE sensor. Then I might take that gap and divide it by two, see if you can shave that off the sensor. What sucks is that there may be either a trigger wheel or ECU issue that makes all of these fix attempts pointless.

 

I've got a thread going over on the Link forums, and Adam is speculating it may be the VTEC solenoid causing a spike... going to test that tomorrow. I'm also planning to see if I can get an inspection cam into the CPS hole to look at the trigger wheel.

Link forum thread

 

Your log should show some correlation between the two, yes?

 

That's what we're working on. Here's a screen shot showing the voltage spike (marked in red - green is the normal 'extra tooth').



Unplugging the VTEC/VTC had no effect. I'm going to try to get some images with an inspection camera today.

 

This is what I'm starting to think. It has definitely degraded over time, starting from no issues at all on the dyno to intermittent increasing to constant. That makes me think 'physical' issue rather than RFI/EM/electrical interference/interaction.

 

Looks like an awesome trip and slick tow setup! That E36 is a beauty. I really wanted an e36 sedan years back but figured I'd have my hands full wrenching so opted for a newer e90. That wagon is pretty!

 

Is the voltage reading on the scope plot correct here? 3.5v seems a little low for the "high" signal, I'd expect closer to 4.5v. But that's me assuming that the expected signal output is 0-5v.

Do you know the setup parameters for the crank sensor? There should be something like "less than this voltage is low" which I would expect to be set around 0.5v, and "above this voltage is high", which may need tweaking given what we're seeing in the plot above.

Also, which 12v circuit is powering this sensor? What else is on that circuit?

I'm slacking off work or I'd dive into the Honda and Link manuals to orient myself...

 

Also of note, the spike seems to be between the same teeth on two of the three crank revolutions we see here. Maybe there's a bit of crap on the trigger wheel?

 

I'm probably just going to muddy things here, but both my cam and crank sensors return in excess of 9v at the high signal, according to the built in ostelloscope(not using kpro). I think I have my high trigger set to 8v.
This is also Z3 sensors, not A2, so not exactly apples to apples.

 

Wingman brings up a good point. Do you have the crank sensor wired to 5v? It's a 12v sensor.

Edit: I guess beerbaron deserves first props!

 

You can't adjust the arming voltages for optical/hall sensors, only reluctor. This is the most info I got from their help menu, sounds like it's fine with either 5, 8, or 12v, but I imagine if the sensors originally intended for 12v, he should be using 12v.

 

Thanks for the input, guys.

The CPS is supplied 12V from the PDM on Mid 11. I need to check my notes, but IIRC, that circuit powers 12V sensors and the VTEC solenoids.

 

That's a little concerning to me - I'd like to see the sensors on a different power supply line than any motor/inductor loads like the VTEC solenoids.

Have you verified that you have 12v at the sensor? Especially when the solenoids are active?

Could you pull the CPS as it is wired right now and record a trace of you passing a large piece of steel past the sensor end so we can see what the maximum voltage is that can be returned?

I'm wondering if the toothed wheel is out of range of the sensor end, either through the sensor being too far away, or the wheel being off-centerline of the sensor, thus causing the weak "high" signal. All the teeth appear to be delivering the same "high" signal, so the sensor-to-tooth distance is consistent.

 

FWIW, I wired every single engine sensor and load on the same relay/feed wire. TPS, Injectors, coils, sensors, and position sensors. Haven't seen any weird noises in them, certainly nothing to the extent that he's seeing.

 

My bad, I posted that from memory, and later verified that only the 12V sensors are on that circuit.

That circuit is logged via PDM and showed consistent 12V at times I was having issues on track. I have checked the voltage at the connector at several points in the diagnosis process and it has always been good.

With the architecture of the K24 engine, I don't see how any of that is possible? The sensor mount is cast into the front cover and the crank wheel is original and is what it is. I did run an inspection cam into the sensor hole and checked the teeth, and they all look undamaged.

I don't have the extra hands around to test the sensor with a piece of steel... might try that when my wife gets back in town.

Crappy pic of inspection camera...




I'm really leaning toward an ECU problem, but may try running a ground wire straight to battery from the ECU grounding point to see if that has any effect.