RX1 weird electrical problem, ECU related

[dhkr123]

Hi.

2003 RX1.

I've been pulling out my hair for the last several hours trying to track down an intermittent electrical problem.

The symptoms are;
1) The tachometer bounces,
2) The engine cuts briefly as the tachometer bounces (stays running).
3) The engine light flashes 3 (thumbwarmer switch disconnected...??) apparently triggered by the same event as the other two symptoms.

Now, having dealt with the sensor wires in the nose, this didn't appear to be too incredibly different of a problem (minus the code 3...), so I went in there and pulled it all apart for inspection. Looked normal, so I pulled a little further at the wiring harness and got all the wires out of the nose and removed the ECU, reconnected the wires with the ECU loose.

Symptoms all remain, HOWEVER, I observed that I was able to make the symptoms WORSE or BETTER depending on how I held the ECU. At this point, you will certainly agree that it seems to be a broken wire, either intermittently connected, or intermittently shorted against something, and that it was close to the ECU, and connecting/disconnecting as I moved it.

After pulling the entire wiring harness off the machine and unwrapping and testing each wire individually, the wiring harness is perfect.

I plugged it all back in and started it up again, moving the ECU around, the symptom had apparently disappeared. Right, not good to have a weird electrical symptom disappear, because it will eventually come back. So I ran it again and moved the ECU around a whole lot more, and about to give up, set the ECU down on its back in the nose. Tachometer dropped to ZERO, engine started running REAL rough. Lifted it back out, ran normal, put it back in, same thing.

Now here's the crazy thing.... the wires checked out when I tested, and to confirm, I made a bracket to keep the wires from flexing. The wires are, as I previously concluded, perfect. The ECU goes nuts when it is in the specific location where I placed it. Move it an inch, and it works normal. Has anybody observed this before? Some kind of interference, maybe from the magneto, causing some stupid transistor to fail? I don't think that there are any kind of orientation sensors in the ECU, since holding it at the same angle in a different location does NOT cause the same problem, and it never shuts off completely.

Now obviously I'm going to need to test out another ECU on the thing before I go out and buy one, anybody know how much they cost new or used? Anybody in or around Toronto/Barrie Ontario able/willing to help me out on this?


Thanks.

 

[brian73]

I don't live anywhere near you otherwise you can try mine sorry did you check all the grounds to make sure they are clean and tight make sure if you haven't yet make sure all the wires in the connector to the ecu are still tight if this don't help I hope you find the problem soon

 

[dhkr123]

Thanks brian73.
Those are usually good suggestions, but they would have been easy to spot when reconnecting the wires after pulling the whole thing out. Unfortunately, I'm not so lucky to have a problem with the wiring.

 

[Bluebullet]

wire testing

DHKR123, I understand you tested the whole harness 1 wore at a time but did you flex the wires during testing to see if you have an intermitant break in an wire. I have been down this road before. I had an waring harness in an old car do the same thing. ended up finding it after pulling alot of hair out. wires had been pinched and rusted inside the jacket and really only found after it finally seperated inside jacket. I have seen conectors get high resitant connection and give you serious headache! I would try a new or differant harness. Battery power good, tight connection? My 03 viper ER would give simular indications with battery (Tach speedo bouncing and going crazy)
just my 2 cents good luck!
blue

 

[grizztracks]

Did this problem exist last season or did it develop while in storage over the summer? It sounds like a ground or corrosion problem. Check the relays, switches and all grounds.

 

[suprfst]

Mine had the speedo and tach messing up. It ended up being the connecton was comming apart right where it plugs into tach (from pounding it down the trails I think). Just had to plug it in all the way. Engine never cut out but I is easy to check.

 

[dhkr123]

This forum doesn't seem to support multi-quote...

Bluebullet: Yes, tried twisting, and in fact STRETCHING each wire while testing. Perfect continuity.

grizztracks: it did, but not quite as bad, or at least I didn't notice the tach flaking out last year. The idle was definitely off, I figured that it would simply be plugged carb or bad plug, and unfortunately left it until it got cold out. There is definitely no problem with ground or corrosion. The machine is immaculate, never seen a spec of salt, only time its ever even been on a trailer was when picking it up new from the dealer, and I think that was either September or October. I did swap the relays (headlight with ignition), no difference. Tested the power, not so much as a blip, so switches are fine.

Note that the engine continues to run even when the tach is resting on ZERO, it just runs real badly when like that.

Steve: if the problem was just the tach, I really couldn't care less. Problem is that the thing isn't running right. The tach is just a useful visual indicator that something's wrong, but even with the instrument panel completely disconnected, it just doesn't run right.


Really, you guys have got to believe me, I've tested this thing to hell and back. Flexing the wires has no effect, when the ECU is in certain specific locations, it just goes haywire.

 

[Crewchief47]

dhkr123,
Welcome to TY! Please take the time to update your location in your profile, thanks!

If you can't find a problem in the harness, it's possible the connection between the socket and the circuit board has issues. I've never looked close enough to one of these to see if it's possible or not.

I can remember the head phone jack on my walkman starting to break away from the circuit board causing intermittent issues that looked like the wire.

Good Luck!

 

[dhkr123]

As I said, its all about location, not flexing.
There is also no way to check the connection between the plug and the circuit board, since, like most ECU's, it is packed with rocks and silicon to make disassembly impossible without destroying it entirely.

I really am just looking for someone either with a spare ECU, or who is willing to let me try their ECU -- I'm willing to bring the machine to test where it would be convenient for that person.

 

[Rockmeister]

Hey dhkr123

I am about 7 hours from you.
If you come here, will do what we can to help!
Have a heated shop, RX-1, & ECU to test with.

Rock

PS Funny, was with Steve when his sled did that.
Think it was all that Trying to keep up with me that shook the connection loose...

 

[dhkr123]

Thanks, I'll keep your offer in mind. I actually found a dealer close by here who's willing to let me test out one of their ECU's on my machine. Going to see them in a few days.

 

[dhkr123]

Ok, so today was WTF day.... as in WTF is the problem with this damned thing??!?!?!


At the onset of this problem, there existed two possibilities;
1) That the ECU is fried and the interference causing the problem is normal,
2) That the ECU is fine and the interference is not supposed to be there.


Brought it in to dealer today to test an ECU from another machine. Well guess what? The second ECU is slightly MORE susceptible than MINE!!!

He agreed that the wires are fine.
And the ECU is obviously fine, since another is doing the exact same thing.

So... WTF???!?!?! It means that there is some unusual EM radiation coming from something, and it is affecting the ECU.


There are precisely two things remaining to do...
1) tech update pickup coil wires rubbing STARTER GEAR under the engine cover.
2) if that's not it, wrap ECU in tinfoil to block EM radiation.
#2 is the F-it option. Prefer not.

 

[dhkr123]

And option #2 it is.....

Right up there with http://zapatopi.net/afdb.html

It must be aliens. Seriously. Everything on this machine is 100% perfectly within spec.



FYI for anyone interested in the technical details, there is actually real science behind this. Essentially, I built a FARADAY CAGE around the ECU to block out EM interference. The main difference between this and a foil deflector beanie (and why a foil deflector beanie won't actually work in its common form....) is that the Faraday cage has to be electrically attached to ground. If you connect your foil deflector beanie to ground, it will actually work

With this in place, the machine functions at 100%. Further proving that there can't be anything wrong with anything that can possibly have this effect.... which proves that one of three things must be true:

1) That ALL RX1's are similarly afflicted. At least all 2003's. Note that the second ECU tested was also from an 03. Theoretically, an 04 ECU might react differently.
2) That logic itself is invalid.
3) That aliens are messing with me.

 

[Jeffz]

I bet it's aliens.

 

[dhkr123]

I figured it out!
It'll blow your mind it is so crazy...

1) Faraday cages don't block STATIC EM fields, so it isn't earth's magnetic field.
2) The effects of external sources of oscillating EM fields would change based on the orientation of the sled -- nope.
3) It MUST be an oscillating EM field originating on this machine.
4) Shielding the WIRES had no effect.
5) Everything INSIDE the engine is shielded.
6) It must therefore be an oscillating EM field, sourced on this sled, not part of the wiring, outside of the engine.
7) If it is not part of the wiring, it must be spinning.

So what is outside of the engine and spinning?
The primary clutch.

The OEM weights are made of non-ferrous stainless steel. Non magnetic and therefore incapable of generating an EM field.
Heavy hitters have IRON in them!
I always store my sled pointing WEST. Earth's static EM field has magnetized my clutch weights!!! When the clutch spins, it creates an oscillating EM field that kills the ECU!!!