Triumphrat

Forchetto · 06-11-2009, 03:00 PM

While sitting on the toilet perusing bike mags and books (as you do), with the wife banging on the door for me to get out, I spotted a bit of humour in the official Triumph workshop manual. It reads thus:

"All models. The throttle position sensor is an integral part of the carburettors and is NOT available separately. If the sensor is faulty the carburettors must be replaced"

This is a joke surely. TPS potentiometers are available separately for any car you care to mention. It's not as if they're an everlasting component. They often fail.

Derby Boy · 06-11-2009, 03:58 PM

I have read the same thing, and the sad part is I don't think it's a joke. I haven't checked "Bike Bandit" to see if it's available but now you have me curious. There have been several debates on here about the worth of the TPS on our Bonnevilles. Many believe you can just disconnect them with little to no adverse affect. Don't remove it as that opens up another can of worms.
Most of the replacement carbs for our bikes don't even have a TPS.

Forchetto · 06-11-2009, 04:20 PM

I can't find it as a separate part on Bike Bandit. No problems though, a set of carbs is just between $1,585.43 and $1,982.95 depending on the year...

The TPS supplies vital info to the igniter to work out the ignition timing. The pick up coil supplies info on RPM and piston position, and the TPS the degree of throttle opening. I would have thought it was a vital part of the system. It will run without it but the ignition timing will only be correct part of the time.

On the EFI models it's even more important as a vital sensor in the loop. Hopefully we won't have to buy a whole EFI system if it fails.

dledinger · 06-11-2009, 05:56 PM

Order the sensor for FCR39s through Sudco - I've put the two side by side, they are identical.

Forchetto · 06-11-2009, 07:02 PM

Quote:

Originally Posted by dledinger

Order the sensor for FCR39s through Sudco - I've put the two side by side, they are identical.

Fantastic find. Thanks. Once you have the part number stated on that site you only have to Google it, and lots of sites come up with spares for that Keihin FCR-MX carb.
The part number to Google is: 1614-862-2100

It's through forums like this that we can beat the system...

noise67 · 06-12-2009, 06:03 AM

Hi, concerning the TPS replacement. I used to work as a Kawasaki technician and it was the same scenario on their fuel injected throttle bodies. Fine if your bike is in the warranty period, if not..........

The reason behind this, its claimed, is that the tps is set up on a flow rig at the factory and is not to be adjusted, or replaced.
Unless of course Kawasaki find that they are getting loads of warranty claims for throttle bodies, as did happen on one of their models. They then will supply said dealers with a new TPS with instructions on fitment.
As i remember this involved setting the TPS measuring the input and output voltages using a Fluke digital meter that reads to 3 decimal places.
Regards
Noise

Forchetto · 06-12-2009, 06:51 AM

Quote:

Originally Posted by noise67

As i remember this involved setting the TPS measuring the input and output voltages using a Fluke digital meter that reads to 3 decimal places.
Regards
Noise

Thanks for your input. The procedure for setting those potentiometers is detailed in all car dealer manuals and, as you say it involves something like: "set tps position at idle using clamping screws until there's a reading of 1.18 volts between terminals 1 and 2, etc".

I'm waiting for the EFI manual, but if there's no info concerning the setting voltages, what I'll do is to check the voltages that my potentiometer gives when new, with the throttle at rest, make a note of it in case of future trouble or replacement.

PAAS · 06-12-2009, 09:39 AM

Quote:

Originally Posted by Forchetto

I'm waiting for the EFI manual, but if there's no info concerning the setting voltages, what I'll do is to check the voltages that my potentiometer gives when new, with the throttle at rest, make a note of it in case of future trouble or replacement.

I think you'll be waiting a long time for Triumph to publish settings for the TPS in any of their future manuals. They've made their position plain in the existing ones. You might find this useful - http://www.triumphtwinpower.com/tps_adjustment.php I understand your concern about this, but having been a Bonnie owner and active member of this forum (and the Delphi forum) for over five years now, the TPS doesn't seem to have been a significant source of electrical problems, unlike the ignition coil, the pick up coil and occasionally the ECU.

propforward · 06-12-2009, 09:50 AM

Hmmm. I have never heard of anyones TPS failing, but that said what a pain in the 'arris it would be if it did. There are some good nuggets of info here, so I'm going to move the thread into tech talk, and link it in the great source of info sticky for help in finding it all at a later date.

dledinger · 06-12-2009, 02:18 PM

It would be a total waste of time to bother setting TPS voltage to 3 decimal places....maybe on some bikes, but not this one.

The TPS is no where NEAR that consistent. Not even close!

I've measured the resistance, range of motion, and physical dimensions of the factory TPS, and the FCR 39 one. I've swapped them also - they are absolutely identical.