4r0 tci

[bikerphil]

Does anyone have the TCI plug pinout for an 81 Standard or Special?

[MaximPhil]

Does anyone have the TCI plug pinout for an 81 Standard or Special?

Hi Phil,
Not sure I understand what you are looking for
Do you need a picture of the TCI or the plug or a schematic of the wiring?

Phil

[bikerphil]

A picture or schematic of the wire colors how they are oriented in the plugs going into the 4RO TCI.

[Ranger_xs1100]

A picture or schematic of the wire colors how they are oriented in the plugs going into the 4RO TCI.

If this helps, A picture of the 4R0-10 from the 81 LH (MNS) that I am currently working on.

[bikerphil]

Thank you Bob. Yes, that is perfect.

Reason I am asking is I have an XJ here with a suspected bad 10M TCI and I have access to a 4RO unit for testing purposes. The bike starts fine cold but about a mile down the road it has one of it's "episodes" of bucking/backfiring/coughing like it is losing spark on 2 cylinders. After a few minutes of doing this, it is fine and runs perfectly from then on after fully warming up. The 10M seems like it gets hotter than normal. Changing out the TCI is my next step after chasing this gremlin for about a week now.

[kboehringer]

'81 is different INTERNALLY

Just an FYI. The '81 TCI is INTERNALLY different than all other model years.

[bikerphil]

Yep, the 2H7 boxes have no timing curve. The 4R0 has the 36* curve and the 10M has the 36* plus the additional 15* boost curve activated by a vacuum sensor. The XJ should run fine with a 4R0, th just won't have that vacuum operated "cruising" timing advance.

[3Phase]

Yep, the 2H7 boxes have no timing curve. The 4R0 has the 36* curve and the 10M has the 36* plus the additional 15* boost curve activated by a vacuum sensor. The XJ should run fine with a 4R0, th just won't have that vacuum operated "cruising" timing advance.

The XJ's 10M TCI isn't entirely pin-compatible with the 4R0 or the 2H7 TCIs.

I'd have to look at them both to get my head around it again but the TCI pins were moved to accommodate the XJ's Boost sensor for the vacuum advance.

The Boost sensor voltage is not 12 volts and I think that one of the pins in the XS harness puts 12 volts on the 10M's Boost sensor pin.

[bikerphil]

Yep, I have the boost sensor disabled at the moment. I have been studying the different pin variations but it seems the fellow that had the 4R0 box to loan me has somehow lost it. My next step is to use the 2H7 box and it's ignition components under the left side cover. The pickup coil wire harness is a bit different, the XJ is 3 wire with a common ground and the old style is 4 wire.

[Ranger_xs1100]

I have one

Yep, I have the boost sensor disabled at the moment. I have been studying the different pin variations but it seems the fellow that had the 4R0 box to loan me has somehow lost it. My next step is to use the 2H7 box and it's ignition components under the left side cover. The pickup coil wire harness is a bit different, the XJ is 3 wire with a common ground and the old style is 4 wire.

BikerPhil,
I have an M10 TCI here that I can loan you for testing purposes. However it came off of my non-running XJ parts bike so I can't promise you that is a good part. But you are welcome to give it a plug and go try if you want to.

[bikerphil]

Thanks Bob, I sent you a PM.

[Ranger_xs1100]

shipped

Phil,
The TCI was mailed out this morning,
You should have it on Tuesday,
Hope it works out for you,

[bikerphil]

Thank you, I appreciate it very much Bob. It should help me greatly to figure out what is going on with this XJ.

[bikerphil]

I received the 10M box from Bob today, thank you very much for the loan. I should be able to try it within the next few days. Meanwhile, I did swap out the whole ignition system with 2H7 parts and the bike runs perfectly now, no ill effects. The problem had to be the 10M TCI, the pickup coils, or the wiring from the pickup coils. I will update when I swap the parts back over.

[bikerphil]

Ok, update... The bike is running fine with the loaner 10M TCI from Bob. Much appreciated Bob. I also slotted the timing plate for an extra 10 deg. of advance off idle for some extra pep. The owner of the bike is very happy that he can ride the bike now without having to push it.