After having three days of Scottish weather, wet, cold and windy today was perfect so I took the bike out and  covered 160k’s with the bike running well. However sitting around 3000rpm and a throttle position of 6ish on the tacho the bike still has a hint of jerking. I was wondering if the TPS could be a bit sad in this spot. Either side of this position the bike runs well. I don’t think it’s a map issue. The bike also did this with the origional ECU, Any thoughts?   :-/

Most (or all) people that replaced the TPS for very similar reasons found it to be a waste of money. If adding some fuel at that cell does not help, try increasing your valve lash just a tad more.

If you have the tacho showing you the throttle like it appears you are, you will see the needle moving about erratically. If it is smooth and following your throttle there is no TPS problem.

Thank you for the info. I have opened up the vale lash from what I used to run to what Raz recommends, which is what I was riding with on the weekend. I don’t really want to go any bigger in the clearances as I have read that it creates more wear in the valve train. I tried to keep an eye on the tacho when I was riding to see if the needle was fluctuating. I thought that at the said position it looked be a little nervous, but not overly noticeable. I will give it another ride and try and get a better look at things. If that looks ok I will check the map and doctor it at that point and see what happens. I thought if I use a multi meter on the tps it might show something up.   

you don't need to run the bike to check the TPS.
A multimeter is ok but an analog meter will be easier to spot any noise.
The ECUController will also output the throttle values.

Yes I realised that I could use ECU controller after my post. I thought, I bet there are few having a chuckle on the forum. ;D I have had a look at start map, and Raz’s map in the RPM and injection duration table. I hope that’s where I should be sussing things out? :-/ Raz’s map has a big drop off in injector duration from 3001rpm to 3501rpm and then jumps up at 4000rpm again. The start map drops off less aggressively around these points. So I guess that would be a good starting point as Raz pointed out. I will also use the ECU controller to check TPS operation.  [smiley=beer.gif]   

Regs wrote on 05/27/12 at 20:23:29:

After having three days of Scottish weather, wet, cold and windy today was perfect

We have just had 5 days of 28^o C - that made me chuckle  :P

28 degrease C, that’s a winter’s day in our part of the world. The little lady of the house comes from Scotland, and the weather is one thing she doesn’t miss. She took me over there in December 2007. I thought it was great as it is totally different to what I am used to. I could not get over the folk riding motorcycles though, rain, cold, fog, snow and ice. I slipped over a couple of times just walking, and I hadn’t had a drop of the local brew at the time. One of the blokes I spoke to said, if you only took your bike out on the fine days you would never get to ride.  How did you go with your wiring?  I will be back in the shed on the weekend to try and sort out my little hiccup area. Have a good one.

Due to going west coast for 4 days with mates (on ST1100 due to drink carrying capacity) I haven't had a serious go at finishing the rebuild. Next Monday I finish work for 3 weeks and the Scottish branch of the MGCGB are heading to Skye (midge country!! [smiley=smiley_down.gif]) for the w/e so I hope to have done by then. I'll find out where the wire goes then - still none the wiser - but having the battery in place will at least give me a clue. We had a great time over west and the amount of bikes on the road was amazing. Warm weather and dry roads sure brings them out. Ill post when I find out where the dangly bit goes. Thanks all for the suggestions.

Regs, what sort of TPS do you have on your bike? The big one or the newer, smaller, more cylindrical cheapo used on the newer bikes (late Sporties and V11 ...). These PF3C (or is it 4c?) in all their crapiness do show a tendency to wear exactly around this area.

http://img404.imageshack.us/img404/7546/leiterbahntps55000km.th.jpg

this is the resistive layer of mine, dissected after only 50.000 km. I'm sure it was already bad at 30.000 (replaced it with the HD version btw.)

hubert

PS: would love to have some Scottish weather actually. Dust and sweat are no fun either.

I have my right hand straddle the bar end to reduce the effect of bumps.

I would say that it has the later TPS. Some time back on the V11 forum I do remember reading about replacing the Guzzi unit with a HD one. The bike has a bit over 30,000k on it. I recon 90% + of the throttle setting would be around the 3000ish rpm. The roads here once you get off the coast are long and straight with 100k between + between towns. But if your head down and ass up with the throttle held hard against the full noise stop you might feel a corner or two, so the potentiometer might have wear at this point. The bike didn’t jerk when I first got it, which showed up somewhere after 15,000K a little bit at a time. It isn’t as bad as it was with the new ECU on board but that could be because of the different TPS setting at idle. I shall investigate this weekend.   
YaBB   (I have my right hand straddle the bar end to reduce the effect of bumps). I take it that’s in reply to trying to get a fix on the Tacho out on the road? Either that or the fumes from the soldering are getting to you  ;D only joking ;D

It's possible to pry off the grey bottom cover, inspect the internals and press it in again afterwards. Carefully, of course. If you should want to try it, carefully clean the outside first, don't clean or grease anything inside. This would probably ruin it. There's a spring inside, too, btw ...
I'm sorry that I don't have taken more pictures.

Luhbo wrote on 05/30/12 at 05:49:20:

this is the resistive layer of mine, dissected after only 50.000 km. I'm sure it was already bad at 30.000 (replaced it with the HD version btw.)

Jesus, what a piece of crap! And I actually thought it was wound (as in past tense of "wind", not injured LOL). I wonder what mine looks like after >80,000 km.

Raz

Interesting. Like Raz I had it in my minds eye to be a "pot" with a coil of wire or something like that. A day without knowledge etc. etc.. :-[

That's Moto Guzzi, some good thinking and then some not so logic stuff with all the technologies out there today. I priced a HD TPS today at $53.58 inc tax. Not on the shelf so will have to be ordered in if mine is cactus. I will test mine and if suss will have a sticky inside as suggested. The Scottish weather turned up again last night. Bugger.

Regs wrote on 05/31/12 at 18:54:37:

The Scottish weather turned up again last night. Bugger.

Can't be! It's here - overcast,12^oC, occ shwrs.

I suppose if the wear is evident you could try re-coating with a thinnish layer of the stuff that repairs car window elements or some conductive paint at a push. Mind you, after all the faffing about involved, it may be as well to buy a new TPS.

raz wrote on 05/31/12 at 09:36:11:

... I actually thought it was wound ...

It is, of course. Otherwise it wouldn't fit into the housing. A bit like bananas. They're only bent for a better match with their yellow 'outies' ;)
They cannot be repaired, btw. No chance. I mean the TPS, not the bananas.

Hubert

Regs, Do you have the HD part number?  I'm beginning to suspect my TPS after 25K, too. :-/

Keep in mind that usually you don't change a TPS as you renew brake pads for instance. The one I show above was quite easily recognisable as being defect by using a simple volt meter.
Also the characteristics of the PF3C and PF4C are slightly different.

Part No 27271-95 I do not know which models it fits so you might have to look on line to see who has fitted it to what or go to a HD shop and compare it to yours. If you search through Guzzi Tech web site and the V11 forum you might find some more info. 

Thanks to both of you for the information!  I will certainly test it first before replacing.

Hey Raz if you’re on this post is this where I should be looking at increasing injdu 6288? Hicup around 3000ish   rpm and TP 6
InjDur 06  3968  7456  7264  7024  6832  6288  5856  3872  4528  4336  4256  4336  4240  4080  3952  3824
I used the ECU controller and didn’t notice anything obvious with TPS readings as I rotated the throttle. On another road run this Avro doing a one handed Cliff I didn’t notice any needle fluctuation so TPS might be ok.  :question

Yes, I suppose.

How’s every one going? Well we have at last had some good weather for riding and I have had a bit of a play with the current map and the bike is running quite well. Might be a tad lean when pushing under load, like accelerating up hill in top gear. Has a good idle with now hick ups when at traffic lights which some seem to experience. I am going to mount the optimiser once I figure a way to make it look cool sitting up front to have a play with out on the road.    [smiley=tekst-toppie.gif]

While possibly not related to TPS condition, experience has taught me to replace all relays. With age, the MG cheapies deteriorate, leading indicators are increasingly difficult starts (embarrasing when parked next to other bikes), and random engine speed / dying when at idle. I was recommended the GM relays, from any Holden dealer model number: IN 0513