low throttle opening glitch

[guzzista]

After getting the AFR sorted out on the Dyno,( major fuel map redo via PC111) throttle bodies vacuum synched perfectly, TPS set at .475 mv, at times I still get a slow speed (and not repeatedly) pop when rolling on the throttle slowly mostly from a stop, but also at 15% or less steady throttle opening...When rolling the throttle rapidly , no problem...What gives?, anyone had a similar issue? or any recommendations?. TIA and happy end of summer...

[Guest ratchethack]

With a PCIII installed, our intrepid Guzzi Master DynoJet Rep recommends a TPS setting of 500-525 mV (TBs linked) with idle set at 1100-1200 RPM. This should help your situation at least a little, if not more. In my case, if I were running at 475 mV, I'd expect (and have experienced) much the same. My Guzzi seems to have a slight preference for settings closer to 525 mV than to 500 mV, and she runs like a Champ.

 

BAA, TJM, & YMMV

 

NOTE: As a point of reference, 500 mV = .5 V.

[Ouiji Veck]

And as always on poping ..coughing issues I sugest world or Raceco valve clearence.

[Guest ratchethack]

And as always on poping ..coughing issues I sugest world or Raceco valve clearence.

An important point to make here, Weej. When I went from US spec .004" and .006" to World spec .006" and .008" (I think it was before the end of the first tank of gas) it made a considerable improvement in this area.

 

Next pass (coming up soon), I'm going to split the difference and try the Roper settings: .005" and .007"

 

Will advise. . . .

[luhbo]

That's great, indeed! I'm afraid I'll never get behind the secrets of this PC stuff.

 

If one has already double cheated the ecu by dynoing the PC on the basis of a non-spec TPS setting why should he then cheat the whole construct again by shifting the basis the third time?

 

I always thought the PC allows it to enrichen or lean out the map exactly as needed?

 

Hubert

[guzzista]

Thanks, guys. As for the valve clearances , I have kept them at 5 and 10 thou since the beginning. Ratchet, you are certainly on the right track on the TPS.What with its 20mv dance plus or minus , having it at the half volt setting definitively ensures that it will be both under and over that mark as it does its inaccurate thing of reading Throttle position. Mine was condemned by the local dealer, replaced under warranty by MI , installed by me( made no difference) and now the original one is back in...yes I would like a more accurate one and would pay good money for it...the HD one? not much better as it also made by Marelli/weber.plus it ceiling of operation is lower due to HD lower redline..Anyway, the search goes on as this is both a diagnostician's delight as its a PITA for the motocommuter(moi) Cheers

[luhbo]

...yes I would like a more accurate one and would pay good money for it...the HD one? not much better as it also made by Marelli/weber.plus it ceiling of operation is lower due to HD lower redline..Anyway, the search goes on as this is both a diagnostician's delight as its a PITA for the motocommuter(moi) Cheers

 

You might find interesting the fact that this TPS crap is genuine designed (made?) in the USA, regardless what may be engraved on the top of it. The company is called CTI, you will find this TPS together with its ridiculous specification on their homepage.

 

The engine redline is quite irrelevant for the TPS itself as the throttle flap makes about 90° here as well as there.

 

Contact them and tell them what crap they sell, maybe they will give a few samples to this forum as a good will action. More likely they will answer that usually you get what you pay for.

So it's interesting to see that a company like HD, actually making quite good profits with their products, also feels the need to use such 5 cent articles in such important places.

 

Hubert

[Alex-Corsa]

With a PCIII installed, our intrepid Guzzi Master DynoJet Rep recommends a TPS setting of 500-525 mV (TBs linked) with idle set at 1100-1200 RPM. This should help your situation at least a little, if not more. In my case, if I were running at 475 mV, I'd expect (and have experienced) much the same. My Guzzi seems to have a slight preference for settings closer to 525 mV than to 500 mV, and she runs like a Champ.

 

BAA, TJM, & YMMV

 

NOTE: As a point of reference, 500 mV = .5 V.

 

What you say is the key.I have an ocational cough when rolling on to the 2600 rpm on my sport 1100i but this is not often and has to do with the mapping(enviromental parameters) I suppose. Definately setting the TPS right voltage is the key to all and to my occation doesn't go any better.

Right now my Guzzi ticks like a swiss clock with everything set up (chip TPs TBs synchronized)

And that justifies my moto which is do it my self with all the knowlege I can have on the issue, cause none knows my Guzzi better than me.

 

THis is the 5th day I am on tour, right now I am In Germany , in place called Pforzheim (near Stutgartt), will stay 1 day more (perhaps 2 )then I head to Berlin.

 

Been already in Mandelo and got the news (hehehe) will 99% go to the meeting at the 15-16 Sept.

Cheers

 

If anyone is in the near and likes to meet drop a PM with phone number, and though I cant't promise I will try checking tommorow a couple of times again.

[Martin Barrett]

What you say is the key.I have an ocational cough when rolling on to the 2600 rpm on my sport 1100i but

 

THis is the 5th day I am on tour, right now I am In Germany , in place called Pforzheim (near Stutgartt), will stay 1 day more (perhaps 2 )then I head to Berlin.

 

 

Looking forward to a full trip report with pictures when you get back

[Guest ratchethack]

. . . . my moto which is do it my self with all the knowlege I can have on the issue, cause none knows my Guzzi better than me.

IMHO, there is NO BETTER strategy for MAXIMUM UP-TIME on the road than this!

[Alex-Corsa]

Looking forward to a full trip report with pictures when you get back

 

Will do , will do.

 

 

About the topic, needless to say thet the correct engine temp 73'+C (-100) and throtle deg. 3.4 to 3.6 for perfect synchronization.

 

[Guest Mattress]

More likely they will answer that usually you get what you pay for.

So it's interesting to see that a company like HD, actually making quite good profits with their products, also feels the need to use such 5 cent articles in such important places.

 

Hubert

 

This is the nature of the beast now in global manufacturing. I work in the diesel engine engineering business and everything gets kicked back on cost. It is all about cheap cheap cheap. Understandable but eventually you reach a point where a good design gets replaced with a crappier but cheaper design, and some marketing clowns do some calculations on warranty returns vs. cost to justify their garbage. In the end the engineer is the whipping boy for everybody when crap breaks or doesn't work. It really sucks sometimes.

[guzzista]

I am wondering if a more precise TPS can be obtained and if as a group ther might be enough inteest to have one made.... as far as any other possibilities any one run into kill switches, relay or sidestand switch problems causing power cutting out momentarily? Cheers

[Guest Jeff in Ohio]

You might find interesting the fact that this TPS crap is genuine designed (made?) in the USA, regardless what may be engraved on the top of it. The company is called CTI, you will find this TPS together with its ridiculous specification on their homepage.

 

The engine redline is quite irrelevant for the TPS itself as the throttle flap makes about 90° here as well as there.

 

Contact them and tell them what crap they sell, maybe they will give a few samples to this forum as a good will action. More likely they will answer that usually you get what you pay for.

So it's interesting to see that a company like HD, actually making quite good profits with their products, also feels the need to use such 5 cent articles in such important places.

 

Hubert

 

I have the specification complete with output graph for the PF3C Guzzi TPS direct from Magneti Marelli. It looks NOTHING like any of the curves on the website you mention (I assume you mean the 510 series). The Guzzi TPS has an output curve made of 2 different sloped lines. Harley uses a PF4C. It's output curve is a little wacky looking....

 

here is the image from a .pdf I have on the PF3C...

[luhbo]

I have the specification complete with output graph for the PF3C Guzzi TPS direct from Magneti Marelli. It looks NOTHING like any of the curves on the website you mention (I assume you mean the 510 series). The Guzzi TPS has an output curve made of 2 different sloped lines. Harley uses a PF4C. It's output curve is a little wacky looking....

 

here is the image from a .pdf I have on the PF3C...

 

Thanks for outcoming, Jeff. This picture is most interesting for me, as my TPS is dead (resistor layer rubbed through) and I'm actually using a DIY version based on a GM pot. I still hesitate to buy a new one. It costs just too much.

 

You have the electrical spec from Marelli. This shows what they purchase from CTS, not that MM would make it itself. Also Harley for sure is buying it there (albeit I've never seen one, but if the housing is the same...).

 

An angled output line is quite seldom when used as a TPS. The reason is probably that normaly a TPS is based on a redundand system because of safety reasons. A car TPS nowadays is in most cases combined with a throttle actuator, so a failure in the sensor can have surprising effects.

 

What I meant with ridiculous specification was for the mechanical part of it. One million cycles as guaranteed by CTS is a b'y joke. 14 millions should be the minimum. I don't want to blame CTS for that, they are producing for higher standards as well. Its more the fact that Guzzi (and Harley) uses such a cheap version.

 

Thanks again

 

Hubert

 

PS: Recently I found these lines on an Italian site:

 

"Adesso lo so venderò questa merda di moto, manderò a fanculo questa fabbrica di Mandello che vende illusioni e rottami e fa pagare un pezzettino di plastica 200 euro, per lo meno la parte di me che ha sopportato i soprusi e l'arroganza di certi stronzi sarà libera e felice per sempre..."