Does a TCI ignition module ever go half bad?

I've got an '82 XJ650 that acts like a bad coil, no or weak, intermittent spark on the outer two. We swapped in another coil and same thing.

The problem has to be in the pickupsor ignition module I suppose. I just wonder if it's common for TCI boxes to go partially out or if it's more usual 5o go out all at once?

 

Check your battery while cranking the engine with a multimeter. You should have 10 volts minimum while cranking the engine. Check the resistance of the pickups on the end of the crankshaft on the gear lever side of the engine. Check wires connection to ignition coil to see what voltage you have. Might not be the TCI. Only way to be sure is with another unit to see if all four cylinders run.

 

ohm out the pickup coils from connector at tci


did you change the spark plug caps too?

could be as simple as bad caps or corroded end of spark plug wire making no contact..

XJ650 models:

Pick-up coils:
1980-81 XJ650 Maxim and Midnight Maxim: 700 ohms +/- 20% = 560 ohms to 840 ohms acceptable range
1982 XJ650RJ Seca (non-yics engines): 700 ohms +/- 20% = 560 ohms to 840 ohms acceptable range
1982-84 XJ650 Maxim: 650 ohms +/- 20% = 520 ohms to 780 ohms acceptable range
1982 XJ650RJC Seca (yics engine): 650 ohms +/- 20% = 520 ohms to 780 ohms acceptable range
1982-83 XJ650 Turbo: 120 ohms +/- 20% = 96 ohms to 144 ohms acceptable range


Ignition Coils:

Primary side (input from main wiring harness):
2.5 ohms +/- 10% = 2.25 ohms - 2.75 ohms acceptable range

Secondary side (spark plug wires, without their end caps):
11K ohms +/- 20% = 8,800 ohms - 13,200 ohms acceptable range


Spark plug caps:
5K +/- 20% = 4,000 to 6,000 ohms per cap acceptable range

Spark plugs:
0 ohms per plug

 

You can , pull the TCI back cover see if printed circuit board is corroded , spray it with electrical contact cleaner , sometimes the soldered joints mat need resoldered .

 

I’ve got the same question. From what I read, the TCI controls the timing advance. Some guy in here went on about trying to get his bike running better, then he’d swap parts off his parts bike. It ran but ran better after swapping the TCI. I’m starting to wonder if my not being able to get my XJ700X to idle isn’t solely a fuel/mixture issue.

 

I

 

Turns out the spark box was full of water. Blew it out and seems to work now. Now I have to get the lights and brakes working.