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Still BAD cough at idle

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I have been using a PF4C Magnetti-Marelli sourced from Harley-Davidson (Buell) for years and years.

 

I am given to understand that the output curve differs from the PF3, but it seems rather transparent to my mediocre skills. 

 

It was also inexpensive and locally available.

 

Wow, looks like the PF4C is not just Buell, but a long list of common Harleys . . .

 

Here is an Amazon listing FYI  ($55.73US) :

 

https://www.amazon.com/Standard-Electronic-Injection-Throttle-2001-2008/dp/B000GZKRY8

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I put one on the Jack-All rig, and truly couldn't tell the difference. It was $42 from the local Harley dealer at the time.

39826295134_e0884ccb3d_c.jpgIMG_5475 by Charles Stottlemyer, on Flickr

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Nice! Looks like a rolling beach party! :rasta::drink:

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OK the new TPS is in and the bike is much better, still cough at idle only when hot. My valves are set at .008 E .006 I.

For those who have cured the cough what are your valves set at?? Or for that matter anyone with a bike with over 50,000 miles what setting are you using on the valves. I am worried that a larger valve setting will cause damage to the cam and the lifters.

Thanks in advance.

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I have been using a PF4C Magnetti-Marelli sourced from Harley-Davidson (Buell) for years and years.

 

I am given to understand that the output curve differs from the PF3, but it seems rather transparent to my mediocre skills. 

 

It was also inexpensive and locally available.

 

Wow, looks like the PF4C is not just Buell, but a long list of common Harleys . . .

 

Here is an Amazon listing FYI  ($55.73US) :

 

https://www.amazon.com/Standard-Electronic-Injection-Throttle-2001-2008/dp/B000GZKRY8

docc, I ordered one of those recently and they're not usable. Note that the attachment screw holes are not slotted hence they can't be adjusted for proper millivolt reading.

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Mine’s been on the Sport years. I guess they were slotted back then?

 

Thanks for the heads-up on the change!

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OK the new TPS is in and the bike is much better, still cough at idle only when hot. My valves are set at .008 E .006 I.

For those who have cured the cough what are your valves set at?? Or for that matter anyone with a bike with over 50,000 miles what setting are you using on the valves. I am worried that a larger valve setting will cause damage to the cam and the lifters.

Thanks in advance.

I set my valves to 0.25mm (0.010") on both inlet and exhaust on the advice of Meinolf. Hot idle smoothed out & I'm happy with the results.

At the same time, I did some other things that could have helped:

-loaded Meinolf's ECU bin file #43,

-set the ECU fuel trim to zero,

-fully closed the air bleed screws,

-correctly set the crank position sensor clearance,

-renewed the rubber hoses from the throttle bodies to the heads,

-made sure there are no exhaust leaks at the cylinder head,

-synchronised the throttle bodies

-back flushed the injectors.

You probably don't need to do all those steps on your bike, but mine has more than 80,000km (50,000 miles) on the clock, same as yours.

I know that I will have to bush the worn throttle shafts soon, as there is slop there, and the engine is sensitive to air leaks.

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I'm having similar difficulties. Although mine idles well at 2000rpm it does cough badly almost pushing the intake rubbers off (which are pretty new).  I know a lot of the time tight valves don't help. With the valves set at 25mm (cold obviously) do you not find that even when the engine is up to tempreature there is a lot valve train noise, is this ok? - M

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M,

 

Seems valve clatter on a Guzzi would be fine as long as you're using a quality SG 20W-50 oil. :huh2:

 

(There are those who go even looser on the valves.)

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OK still at it , Still cough (bad at idle) new cam chain tensioner, new tps, new head temp sensor, did the tune up.

Went all through it again all good till warmed up, unplugged the head temp adjusted the idle runs like a champ,

just as it used to!! So now is this pointing to a ECU problem? From what I understand the ECU switches to a different

map when the temp gauge tells it is good to go. Is there a problem running the bike like this, IT RUNS PERFECT!!

Or is a new ECU in order?

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Understood, 1200rpm when smooth, power commander reading and verified with guzzidiag.

It is hard to fathom that your ECU needs replaced.  Worst case there would be to rewrite the map to it?

 

Sorry, but is there still a PowerCommander in the mix?

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OK still at it , Still cough (bad at idle) new cam chain tensioner, new tps, new head temp sensor, did the tune up.

Went all through it again all good till warmed up, unplugged the head temp adjusted the idle runs like a champ,

just as it used to!! So now is this pointing to a ECU problem? From what I understand the ECU switches to a different

map when the temp gauge tells it is good to go. Is there a problem running the bike like this, IT RUNS PERFECT!!

Or is a new ECU in order?

Air Intake Sensor.jpg

The ECU takes an assumed value for temperature when a sensor is unplugged.

If it runs better unplugged, then tuning is bad, it is probably running too lean.

You could try using Guzzi Diag to set the fuel trim to zero, or if it is already there, try +10, or so.

I think you will need to connect the sensor and clear ECU faults before you can adjust fuel trim.

Guzzi calls that sensor on the head the "Oil Temp Sensor", and says in the workshop manual "the ECU uses the oil temp signal to adjust..." as the signal is added to the inputs from other sensors to optimise injection duration and ignition timing.

The bike will behave better at all ranges of engine and outside temperature if you leave it connected and fix the tuning.

The attachment shows the air temp sensor in the air box, but the oil temp sensor is just as important to the ECU.

BTW, if you have a power commander, try running the bike without it. It, or the connectors to it,  can go bad. 

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Yes it does have a power commander. and I have ran it un hooked all the same. Will try +10 on the trim.

Its just that to me all else must be correct, if when hot it runs perfectly with the oil temp sensor unhooked.

If its lean then why still the cough with the air bleeder screw fully closed?

Will be back at it on Monday, and thanks for the help I think we are going in the right direction.

Heading out to seneca rock wv for the weekend. No wind on the bay.  

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