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I think I got it, well most of the Cough

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what CO value shows your engine when running at idle? Should be at least 3.5 %.

This together with Synchronisation and TPS adjustment should cure the symptoms.

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This is a plea for forgiveness from the board on my Rosso Corsa.

 

My "fixes" have not worked so I "punted" and took the V11 to a Duc Race / tuning specialist that is close by.  He put a new map on it, removed the power commander III, set the lower end of the map +22 whatever that is, balanced the throttle bodies, reset the TPS electronically and set the air bleed screws correctly.  My CO at idle is 3.5%.

 

I made a check run from the shop and found it to run better than it ever has with a little detonation at 1/4 throttle and medium load in any gear, so i paid the man and rode it home.

 

1/2 mile from home the V11 was hot and acted as nasty as ever.

 

I trust the tune.

 

Once home, I checked for exhaust leaks and found sizeable ones at the inlet to the x pipe on both sides and at the head to exhaust manifold on the right cylinder, the nut needed tightening.  

 

I suspect it's an exhaust problem so now I'm going to go down the exhaust "rabbit hole" with new exhaust manifold gaskets, permatex copper spray gasket for reseating the x pipe and adjusting the valves once again to .15 / .20.  Previously they were .10 and .15.

 

I'm also going to check for intake "backfire" by sliding the airbox boots off the throttle bodies to see if there is a "flash" when the engine coughs.

 

Another test ride ------- and if that doesn't work it's back to the Duc tuner for more experimentation.  

 

The "getting it run right" adventure continues.......

 

Mark

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Progress!

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detonation means it's running lean or too much timing.  Can't be good unless you throttle past it.

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Hello, maybe a leak in the inletmanifold. Spray with breakcleaner in the area from cilinder to throttlehouse and nothing must change. If the engine is going to run different then there is a leak. That can produce the caugh.

 

 

Verzonden vanaf mijn iPad met Tapatalk Pro

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Update: 

 

At the local independent Duc shop I had the Power Commander removed and reflashed the ECU.  He also calibrated the TPS (electronically), balanced the throttle bodies and set the idle.

 

The Lemans ran better and was improved for a longer time butt always the big butt, the "coughing" (backfire?) came back with a vengeance when hot.  It's been over 100 for most of the month and with the stop-n-go traffic it's tough on a Guzzi.

 

Time to fiddle with it at home again before I take it back to the shop.

 

I checked the intake for leaks with no leaks.

 

The tune was decent so I figured I had to go at it from a different angle.  Maybe the valves were still to tight?

 

I readjusted the valves to Raceco specs (.20 & .25).

 

The cough is still there when hot,subtle, hiding and now at 1500 to 2400 rpm.     -- a sneaky little Gremlin---

 

The Lemans is now rideable and I can finally take it on long rides with some confidence.   :)      It's tough buying a touring machine and not being able to tour on it.

 

I'll probably ride it for a month or so and cogitate opening up the suspected exhaust valve to .28 or taking the Lemans back to the Duc shop to have them check the ECU behavior for heat inputs from the cylinder temp sensor and maybe increasing the fueling at 1800 to 2400.

 

Mark

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What about using guzzidiag to evaluate the readings from the Engine Temperature Sensor and the Air Temperature Sensor ?

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That RPM range is just off idle, which makes me think it’s a ECU issue. The idea to check the sensors is a good one, but it also reminds me of Docc’s TPS issue.

 

The cough comes at the same point every time, right off idle. Since it idles and runs well otherwise, check the ECU/sensors first and then measure the TPS as you rotate through the range to see if there is an issue. Docc can point you to the right thread for more info.....I know the TPS is supposed to be new, but I have had new parts (especially electronic ones) be bad.

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TPS calibration electronically is not possible with the 15M ECU. Check this with a Voltmeter!

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I tried to drop the Lemans off at the Duc shop Monday but he's booked out two weeks so once again I go down the rabbit hole. 

 

My plan is:

1.  Pull off the exhaust and seal all the connections with Permatex high temp.  ---The Duc mechanic said to seal all exhaust leaks first----

2.  I ordered a Chinese Guzzidiag connection harness then found out I should order one from Lonetec so I did.  The Lonetec cables should be her next week.  my chinese cables are taking a slow boat......

3.  Download Guzzidiag then get it up and running

3.  Heat up the Lemans and see what the cylinder head temps is to check the sending unit & wiring.  it wouldn't be the first time a bad wire was the problem

4.  Attach the tps breakout harness and see what the TPS does when I wring the throttle.  I figure it's fine because the behavior of the old TPS on the meter was why I bought the new one this year.

5.  Check to see if the CO is set to zero.  

 

So I have guzzi chores into next week.

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This is a great plan! :thumbsup:

 

Lonelec is a reliable source. The Chinee cable I bought was incompatible.

 

"Grooming" the exhaust connections (front-to-back/all), in somewhat of a *star* pattern, using a soft mallet to bump them about like you are tuning a tuba, is good medicine. :luigi:     Go for least stress at the heads (don't make them the last place to tighten).

 

I've never looked for a TPS fault with guzzidiag, but found that resistance/Ohms (through the opening and closing range) showed my TPS fault when millivolts did not.

 

> +1 on motoguzznix saying the TPS can only be calibrated with a [quality] voltmeter.

 

Be sure to use a fan to waft air over the cylinders and heads while you mess about. No use sending the sweet thing into a hot bother . . . :sun:

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stock crossover? I had that and fixed it with a mistral x-over.

I put a ghezzi and brian crossover on my 03, and it make a huge difference.

Also make sure you check your cylinder stud torque.  not uncommon to have them loosen - loss of compression results.

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Checking the Exhaust system at home I found the stock headers were leaking at the balance tube - "big time".  So I pulled the exhaust system, ordered a set of Mistral headers from MG cycle then waited (not in stock). 

 

The crossover is a Stucchi -------Why a balance pipe and crossover?

 

I received the Mistral headers used permatex exhaust seal and put it all together.  The exhaust is much quieter (so that's why...) butt  (always the big butt) the Cough is still there, substantially subdued.  So down the rabbit hole I continue.

 

What about using guzzidiag to evaluate the readings from the Engine Temperature Sensor and the Air Temperature Sensor ?

I received the Lonetec cables, checked the Rosso with Guzzidiag and have seen that the cylinder head temp sensors and air temp sensor are working.  (The readings moved as things heated up).

 

My CO trim is set at 27.  The TPS is 4.71 at idle.  Idle varies around 1350.

 

I was not happy that the throttle reads 2.38 degrees open when at idle but I'm not where I want to change it yet.

 

Now that I know the sensors are working and the exhaust leak is taken care of.

 

Back to the Duc shop for analysis although there is this nata-rally coming up in Utah that the youngest son and I were looking at.

 

Mark

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Why not zero the CO? :huh2:

 

The throttle angles are not significant as long as the TPS was meticulously baselined at 157 mV using a quality voltmeter with the throttle plate completely closed (no stop screw, no ball linkage attached, no fast idle cam, clean bore).

 

 

(After I wrote that, TPS = 4.71 volts at idle? And 2.38 degrees of opening at idle? Both of those metrics look rather low for a high-ish idle of ~1350. I suspect the TPS is not actually zero'd.)

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I feel your pain. I have 04Lemans Docc has been helping me with to cure same behavior it's had for probably 40-50K miles of 72K total. Been thru every check/upgrade I've seen mentioned in threads related to this issue and no improvement o date.  Just got back from 500 mile weekend ride over twisty back roads around Tellico Plains, Tennessee.  Pops thru intakes on every roll off of throttle from anywhere between 3000-6000 rpm to drop gears entering into and exit out of tight curves.  At times, severe enough to create unexpected excitement in holding lane position.  Also, does it nearly continuously when running steady at low speed/1st/ 2nd gear from 2000 to 3200 rpm, like approaching driveway in neighborhood or town traffic or similar. 

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