TCI Replacement 2020 It Works

Team Junk said:
I suspect the devices just to left of the resistors hooked up to the PC terminals are op amps to condition the pickup signal for feeding into the plc...
Click to expand...

The tiny black rectangular 3-pin devices are SMT transistors.

It wouldn't surprise me that it may have adaptive inputs. And agree with Jack's suspicions that the rare-earth magnets give considerable overdrive. *Could* be the source of the initial excessive timing.

As such, Jim's 4.7k termination resistors, or even less, could be tried...
 
TwoManyXS1Bs said:
It wouldn't surprise me that it may have adaptive inputs. And agree with Jack's suspicions that the rare-earth magnets give considerable overdrive. *Could* be the source of the initial excessive timing.
Click to expand...
The rotor I'm using is a rewound OEM... no rare earth magnet... old, original 1980 TCI magnet.
Edit: Rudy's (azman) rotor is also an old OEM that I rewound.
 
Yes the gn250 uses a reluctor. And yes the signal has to be much lower on the 250. Twomany , thanks for getting a better view of the top of the micro controler

I'm having the same problem Jim had finding the rat shack resistors The other boxes are one of three places . Anything smaller than a car can get lost here easily. I will find them in the AM.

I not so sure that the box Steve has still works. I'm saying that was the box I was testing with.
The box with the negative pickup grounded I think will will work better because having the centertap ground will at least prevent the advanced coil from directly influencing the idle coil. That would leave only interference in the wiring from causing a ghost signal. Differential inputs are kinda of iffy in a vehicle environment because of the RF from the alternator and the ignition system.

Jim the connector end pops out pretty easily. Would be interesting to see if the wire colors inside the box are the same.

Think either way that grounding the - pickup even on the balanced input boxes will probably abate the warmup problem.
 
Jim said:
Not sure what you wanted me to recheck Steve... but I'm glad I did. Here's the new box I checked yesterday... still the same.

Input neg. to gnd.... continuity

View attachment 169914



Input pos. to gnd.... 4.5megs (I'm rounding here)

View attachment 169915


input pos. to neg. ... 4.5megs

View attachment 169916


OK, so... turns out I wasn't stoned the other night when I checked. Here's the same drill on the old box.... the one I been running in my bike.

input neg. to gnd... 5.5megs
View attachment 169917


input pos. to gnd.... 5.5megs

View attachment 169918


input pos. to neg... 16.5megs

View attachment 169919

So, on my new box, the negative side of the trigger input goes to the chassis ground... just like the one Steve dissected. The old box.... the one that we know works 'cause it's the one I been road testing.... doesn't. It has a floating input... that's not grounded.

Jack, ohm your box and see what you get? Larry, Jeff and Rudy, if you guys could do the same it might help figure out what's going on.
I've got a ton of stuff to do this week, but I'll try and install the new box and run it tomorrow. See if it acts the same as the old.
Click to expand...
I will ohm the first of the boxes which I received yesterday.
Pretty busy here, too, but I'll get er done.
 
Radio Shack has a fond, old place in my heart.

My 70's era burglar alarm system is still functioning.
I still have little electronic packets like Jim's, with resistors.

I regularly use my battery tester
xxxxxxxx.jpg


Thankfully, there has been one about 10 miles from me.........until now :(
They musta closed this spring.

However, in the city (30 minutes away) there is an old fashioned, honest-to-goodness electronics store which has EVERYTHING:


6W2Fm3x1lm5tPRTl1hjUsiJyCm54Eakwp=w768-h768-n-o-v1.jpg

Stewart W Smith Inc
 
Last edited:
Paul Sutton said:
Somewhere in a small village a family works 24/7 soldering all the components on the board for next to zero pay.
Click to expand...

Perhaps the Jones family solders the - pickup to ground and is low on potting material while the Smith family attaches to the floating input and has plenty of potting material on hand
 
TwoManyXS1Bs said:
The tiny black rectangular 3-pin devices are SMT transistors.

It wouldn't surprise me that it may have adaptive inputs. And agree with Jack's suspicions that the rare-earth magnets give considerable overdrive. *Could* be the source of the initial excessive timing.

As such, Jim's 4.7k termination resistors, or even less, could be tried...
Click to expand...


I may be imagining things, but I swear I am getting a lot more kickbacks at startup with the neo magnet even with the stock system.
 
Possibly. I dug out the remains of the shattered magnet and very slightly opened the hole with a 1/4" drill turning backwards for the new 1/4" magnet. It nestled in there very snugly, so the timing must be pretty darn close.
 
Check your timing. The neo makes a bigger field so the timing might be somewhat earlier.
This brings up a big point. Anytime the ignition system is tinkered with even replacing stock parts the timing should be checked.
The gonzo mods are big time tinkering so caution is required.
 
One thing I noticed probing the gonzo box is that there is a cap across the input. I'm sure to cut down on ringing in the coil. May explain why the box freaks out when wired backwards.
 
Jim said:
Not sure what you wanted me to recheck Steve... but I'm glad I did. Here's the new box I checked yesterday... still the same.

Input neg. to gnd.... continuity

View attachment 169914



Input pos. to gnd.... 4.5megs (I'm rounding here)

View attachment 169915


input pos. to neg. ... 4.5megs

View attachment 169916


OK, so... turns out I wasn't stoned the other night when I checked. Here's the same drill on the old box.... the one I been running in my bike.

input neg. to gnd... 5.5megs
View attachment 169917


input pos. to gnd.... 5.5megs

View attachment 169918


input pos. to neg... 16.5megs

View attachment 169919

So, on my new box, the negative side of the trigger input goes to the chassis ground... just like the one Steve dissected. The old box.... the one that we know works 'cause it's the one I been road testing.... doesn't. It has a floating input... that's not grounded.

Jack, ohm your box and see what you get? Larry, Jeff and Rudy, if you guys could do the same it might help figure out what's going on.
I've got a ton of stuff to do this week, but I'll try and install the new box and run it tomorrow. See if it acts the same as the old.
Click to expand...
OK, so i've got 2 GN boxes at this point, from the same seller on Amazon, Succone in CA.

I checked them on the ohmmeter:
With Jim's assistance, we concluded from the numbers that both have the negative side of the input signal grounded to the box ground
 
Last edited:
YamadudeXS650C said:
With Jim's assistance, we concluded from the numbers that both have the negative side of the input signal grounded to the box ground
Click to expand...

I think that is a good thing. The one I'm using is a grounded one and Jim's was ungrounded. we know Jim's ungrounded box works at high speed. The stock tci pickup is easy to hook up to ether one because none of the three wires in the pickup references ground.
So In theory grounding the - pickup input on a balanced one will accomplish the same thing. I suspect Jim may have tried the grounded one by now???????.

Grounding the - pickup on the ungrounded box should work.
 
YamadudeXS650C said:
OK, so i've got 2 GN boxes at this point, from the same seller on Amazon, Succone in CA.

I checked them on the ohmmeter:
With Jim's assistance, we concluded from the numbers that both have the negative side of the input signal grounded to the box ground
Click to expand...
Thanks for checking Jeff. By my count, that makes 4 boxes with the input grounded on one side. The one Steve dissected, Jeff's two and one of mine. The sole outlier being the one I'm running on the SG. Go figure...
 

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