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Poor running Q

JayDeeca

JayDeeca

Tuned and Synch'ed
GT Contributor
Joined
Aug 21, 2012
Messages
65
Location
Grand Forks, B.C.
I posted a long message last night that seems to have gone missing, so I will repost.
This is the first FI bike I have had, so the system unfamiliar to me. The Quota has 28000km on it, and is running the PCIII. It runs really rough at anything below 3500. There is occasional popping back through the throttle body, as well as popping through the exhaust on deceleration. Unless I am extremely careful, under load the progression from idle is very abrupt, and the deceleration is almost like I chopped the throttle. Above 4000rpm is seems to run well, although I can't really tell as at that speed I can't hear the engine well. It pulls like crazy from 4500 upward. In short the bike is intractable at low speeds, and is hard to get off the line; it would be dangerous to be driving it in any sort of traffic with the way is responds.
The popping and farting would, on a carbed bike, indicate to me that the cylinders were out of synch, but I don't know about an EFI engine. So I used my digital manometer on it tonight, and at 1100rppm the balance says I have 12mbar on the right side. At 3000rpm I it is only off by 1mbar. The idle is set at 950rpm which seems low.
I checked plug gap, and it seems okay at .7mm, although I will buy a new set tomorrow just in case. I was going to check and reset the valve clearance if necessary to see if that makes any difference.
This is a new-to-me bike, so I do not know its history, or when the fuel filter was changed. Is there anything else I should be looking at to get this old girl running a lot more smoothly?
Thanks!
JD
 
john zibell said:
Start by following Mike's instructions. The Quota instructions are near the end as it is different from all the others.

http://mphcycles.com/tuning-the-guzzi-efi/

Then set the TPS to 1.4 +/- 0.3 degrees.

If this doesn't help, let us know.
Click to expand...

Thanks John, I will do that. But I guess what I am asking is if the symptoms I describe, of choppy throttle, popping back etc, are consistent with an imbalance or TPS issue. From what I have read on this site and others, one should not start messing about with the balance unless absolutely required.
Thanks
JD
 
Certainly sounds like it could be a dirty or faulty TPS. Temporarily remove the PCIII from the system until it runs without issue, then pull and send me the PC map. It could be amplifying the problem.
 
JayDeeca said:
john zibell said:
Start by following Mike's instructions. The Quota instructions are near the end as it is different from all the others.

http://mphcycles.com/tuning-the-guzzi-efi/

Then set the TPS to 1.4 +/- 0.3 degrees.

If this doesn't help, let us know.
Click to expand...

Thanks John, I will do that. But I guess what I am asking is if the symptoms I describe, of choppy throttle, popping back etc, are consistent with an imbalance or TPS issue. From what I have read on this site and others, one should not start messing about with the balance unless absolutely required.
Thanks
JD
Click to expand...

Jay,

Since it is a new to you bike the intent is to get everything set to specification. That will establish a baseline for any further troubleshooting. Also Todd's idea of removing the PC III is also to help establish a baseline. Get it as good as possible without the PC III, then set that unit up correctly.
 
GT-Rx said:
Certainly sounds like it could be a dirty or faulty TPS. Temporarily remove the PCIII from the system until it runs without issue, then pull and send me the PC map. It could be amplifying the problem.
Click to expand...
Thanks Todd for your suggestion. As I said, I am green when it comes to this electronic stuff. Can you instruct me as to how to pull and save a map? I have the original documentation and a CD for the PCIII as well as a patch cord, but don't have a clue as to how it all works.
John D.
 
john zibell said:
Jay,

Since it is a new to you bike the intent is to get everything set to specification. That will establish a baseline for any further troubleshooting. Also Todd's idea of removing the PC III is also to help establish a baseline. Get it as good as possible without the PC III, then set that unit up correctly.
Click to expand...
That makes sense. I will see if I can figure out how to disconnect the PCII tomorrow and go from there.
John D
 
I removed the PCIII set up today and plugged in the original harness. Took the bike for a run, and it is still popping back through the TB and exhaust. Next I will check the TPS; I am going to use the mV to degrees method as described in the MPH article.
Two other things; first I replaced a mismatched pair of plug wires to two resistor type NGK, and new plugs. Second, when I removed the ECU, there is something rattling around inside it like a loose nut.
Insurance runs out on the Q on Friday midnight, sure hope I can get this all resolved by then. Nothing worse that starting spring riding in March with a bike that needs repair!
Thanks
JD
 
JayDeeca said:
Thanks Todd for your suggestion. As I said, I am green when it comes to this electronic stuff. Can you instruct me as to how to pull and save a map? I have the original documentation and a CD for the PCIII as well as a patch cord, but don't have a clue as to how it all works.
Click to expand...
Jay, the unit has to be on the bike, or powered by a 9V adapter sent originally with the PC. It's pretty easy. Install the software (download it from here; http://www.powercommander.com/powercomm ... fault.aspx ), once connected to the bike, connect to the PC with the supplied cable, and turn the key on... then simply select "Get Map" > "Save Map" to your computer, and send to me direct.
I read your post above. For sure check the TPS by monitoring the mV. Any spikes or dead spots in the transition means it's dirty or bad. Good job on the plug wires, and nothing should be rattling around inside the ECU, so that's suspect as well.
 
Exhaust and/or intake leaks can produce symptoms very similar to what you are describing... You probably checked that already but if not, it may be worth a look...
 
So I figured out how to read mV on my multimeter. Never had to use that scale before. On the 200mV scale, I read between 2.2 and 2.3 mV. According to the "Volts vs Throttle Opening" graph, that is 19.4 to 21.8 degrees, correct? If I am supposed to set the TPS at 1.4 degrees, the graph does not provide that low a mV reading. Any suggestions? I sure appreciate everyones input on this, I am learning!
JD
 
JayDeeca said:
Is that the VDSTS unit I have been reading about? JD
Click to expand...
Yes it is. Goes by the name Centurion now.
 
This project is going to be on hold until I get the proper tools to diagnose the underlying problem. In the meantime, is it possible/adviseable to remove and clean the TPS? Or would I be inviting more gremlins?
Also, the rattle in the ECU is bothering me. A lot. Anyone successfully open and reseal the ECU can? I'd sure like to see what is loose in there.
JD
 
JayDeeca said:
This project is going to be on hold until I get the proper tools to diagnose the underlying problem. In the meantime, is it possible/adviseable to remove and clean the TPS? Or would I be inviting more gremlins?
Also, the rattle in the ECU is bothering me. A lot. Anyone successfully open and reseal the ECU can? I'd sure like to see what is loose in there.
JD
Click to expand...

Some have had some success in cleaning a TPS, but it is only a temporary fix. It will continue to go bad. As for the ECU, unless you have experience in printed circuitry and conformal coatings, you will only be inviting disaster in taking the ECU apart. With that symptom I'd be looking for a replacement ECU as that could be the problem. Any 15M will do and Todd can re-flash it to the Quota map.
 
Hey Todd;

Can you check your mail.......... I sent you a note regarding concerns.

Thx. Dale
 
I hooked up the Centurian (received it yesterday) and the TPS gives me a reading of 2.27/2.3, and from what I understand, this should be at 1.4 (+/- 0.3). How does one set the TPS? The VDST info says " the software can be used to manually set the TPS...", but the Quota ES manual says the TPS must be manually rotated to calibrate it. Which is it, and if it is done thought VDST what is the method?
I have my fingers crossed that this TPS mis-adjustment is what is creating the running problem.
One other thing, while I had the VDST hook up, I very slowly rolled on the throttle, and the TPS values progressed smoothly, with no skips, jumps or gaps, which, given the notchy running symptoms, surprised me.
Is there a way on VDST to change the TPS readings from degrees to mV and back?
Thanks!
JD
 
Centurion will only read in degrees. Loosen the two screws that hold the tps. Turn on the key then click the connect button on Centurion. Rotate the TPS until you get 1.4 degrees (or as close as you can get it). Note: as you tighten the screws the reading will change. It may take a bit to get it where you want it to be..
 
I warmed the bike up, set the throttle to 100rpm with my Harmonizer, then shut down and set the TPS at 1/35. The result was that the bike ran very poorly, spitting back etc, rough, strong rich exhaust smell.
Shut down, set TPS to 3.7, started up, set idle speed to 1150, ran not bad, but real rich exhaust smell. Shut down.
Reset TPS to 1.7. Extremely choppy idle, would not keep running, Shut down.
Reset TPS with bike running to 1.9, still very choppy, idle had to be reduced. Very rough idle.
I'm not getting very far with this. Before I shut down for the day I removed the tank so that I can play with the balance a bit, se whether I can make any improvement. Looks like I need to buy a slender 18 inch slot screwdriver. Common consensus seems to be to strive for perfect balance at 3000rpm and not worry about idle balance, correct? And, of course, bypass screw shut.
JD
 
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