Throttle body cleaning went wrong (till now)

Owning my GRiSO 2009 it never had a great running engine.
It felt like misfiring between 2 and 3000 rpm. Idle was perfect.

Replaced all parts involved as leads, Phase sensor, spark plugs etc etc.
Last thing on my mind was throttle body cleaning.

Removed parts and yesss it looked necessary.[You must be registered and logged in to see this image.]

So started cleaning with carburettor cleaner and a toothbrush ( an old one)


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After starting the engine it runs worse than ever.

Do i have to anything with Guzzi diag?  it misfire terrible. Idle run at 2500 rpm.
What th hell did i do wrong??

Removed again for inspection but couldn't find anything (at sight) wrong.

Air leak? Were the boots seated and clamped correctly? Gaskets on the inlet manifolds damaged?

You didn't put carb cleaner in the idle stepper by any chance?

You mean false air? Soundslike i need to buy a cigar for a smoke / leak check. But yea it is possible. Thanks. I used new gaskets as seen in picture.

It looks like someone has messed with the LH throttle stop screw at some point. That could be bad.

You took the manifolds off. Why? And did you replace the manifold gaskets. There could be a leak there.

Are all the hoses connected to the airbox, stepper, blow by and the two drains? Are the drains complete and plugged?

Have you performed a TB balance? Did you clear the trims or disconnect the battery during this operation?

Going to check everything a second time.
Taking the manifold of made it easier. No need to remove the airbox.(no experience taking the throttlebody´s off)

Battery was disconnected.


To do:
Check hoses.
Do Throttle body balance.
Do TPS reset.
Self learning.
Make a video for learning purpose.

Measured distance the distance between throttle body stop's both wher closed. (measured with device to measure valves (voelermaatjes in Dutch)


Used new manifold gaskets so should be ok.
All hoses connected. Before cleaning the bike was stuttering from 2 to 3K rpm.
Can imagine that beyond 3K (higher rev's) it's hard to feel but could be there.

Yes the left hand throttle stop is questionable looking at he yellow paint.
Does TLM has a new set?  

I know this is a tough job and maybe not possible. Buying a second hand replacement will probably give same issue's. But why does it run after cleaning that bad?

Thanks all for reacting.

As can see the lh throttle stop seems to be messed with.
Rh throttle stop not.

This set up was ok with dirty throttle body's, but is not with cleaned. (or it is otherwise)
Cant get the idle to where de ECU want's it to be.

Now in a state of doing what Pete told us not to do.


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Quote :

Now in a state of doing what Pete told us not to do.

Stop. Don't.


You say it was idling well before you cleaned them? What RPM did it idle at?


Also, you didn't answer my question about carb cleaner in the idle stepper.

Beetle
I did no spray carburetter cleaner in the idle stepper.
Before cleaning idled at 1250.

Idea to block the stepper? I mean to block the left and richt throttle and see what happens?

Removed and installed everything for the third now with the most precision.

Same issue occured. What is it that makes it idle that high if it is not false air and everything closed?

Stepper stuck open would cause a high idle. Maybe not at 2500..that is more likely an air leak.

Just trying to cover all bases. It may be worth blocking the stepper inlet to see if there is any difference.

To me this, unfortunately, sounds pretty terminal.

If the throttle stop has been moved, especially if it is not known how much, and the TPS has been recalibrated then the baseline for the map has been lost. Now it may be that there is also wear in the TB spindle bushes and the throttle plates will of scalloped out the side of the choke of the throttlebody itself. Now previously this may of been partially occluded by the build up of mank in the TB’s and also the ECU will of been trying to, and to some degree, been successful in trimming around the changed air flow.

The problem now is that having disconnected the battery the trims have been lost and the TB’s now being clean the AFR at idle is going to be all over the place like a mad woman’s shit. Throw in the fact that the ECU is now working off an improper baseline and it’s going to make it very hard, if not impossible, to regain any normality.

In situations like these I never used to have much success in recovering function. Michael is a positive miracle worker in this regard and while he will be the first to tell you he’ll not be able to get it *Right* he often, I might even say ‘Usually’ manages to get some semblance of a working idle. There again he used to work at one of the best carburettor and fuel injection shops in eastern Oz so it’s not altogether surprising. That doesn’t really help you though.

This is, unfortunately, one of those cases where the only real fix is likely to be new TB’s. As a point of interest how much side to side play is there in the throttlebody spindles in their bushes? If you grab the bell crank arrangement on the left and, separately, the arm the linkage rod goes to on the right and you hold the throttle plates slightly open, how much side to side movement can you detect?

Pete,
No play felt. I sprayed carb cleaner while on it's side in it. Minimal leakage on both side. So it seems like all is closed.
But cleaning a carb will maker the engine does 2500 at idle seems strange to me.
In the afternoon perhaps time to close the stepper by hand. Last thing are the rubber o rings of the two new (deliverd by TLM) injectors. After thes actions i no there is no air leakage.

Will a second hand set throttle body's with all yellow paint in place be an alternative on a new set ?

To be continued

Deepdive, in Feb 2022, you said when you purchased the bike it had an idling issue? What did you do to fix that?

Last year, you installed one of my maps. You would have had to reset the TPS after installing the map (it's in the procedure).

In this thread's first post, you said idle was perfect. If so, then resetting the TPS wouldn't have affected it, given it has been remapped. Unless I am missing something? Did you actually reset it at that time, or was the bad idle fixed in 2022 by moving the throttle stop?


Curiouser and curiouser....

[quote="beetle"]
Deepdive, in Feb 2022,  you said when you purchased the bike it had an idling issue? What did you do to fix that?

Last year, you installed one of my maps. You would have had to reset the TPS after installing the map (it's in the procedure).

In this thread's first post, you said idle was perfect. If so, then resetting the TPS wouldn't have affected it, given it has been remapped. Unless I am missing something? Did you actually reset it at that time, or was the bad idle fixed in 2022 by moving the throttle stop?


Curiouser and curiouser....




When purchased there was indeed an idling issue.
The bike did not run for a long time before i bought it. But after let say 1000km the complaint was gone.

The complaint with not the best running at 2 to 3k stayed with whatever map i got. A bit more fuel for the bad range and trying diff CO (now on 6)
Yes followed procedure with the Guzzi Diag tool.
Replaced phase sensor leads bougies etc etc.

Finally can bring the GRiSO to TLM but maybe cheaper to buy a new throttle set. Simple install.

Just an idea about syncing TB's. If way out of sync and you screw in the balance screw to get the equal. You get to a point where you raise the idle mechanically. Even though they are balanced on the big end the idle will not come back down. I have had this issue when tuning the TB's.
There are only 2 alternatives, turn the idle stop and do not reset TPS(so you know where it's at) or go back to out of sync so idle comes down.
Could it be clogged bypass air screws? These are the only things i could come up with if all you did was clean TB's.

Edit: I am not saying to turn the idle stop screw, it should not be messed with.

Bypass screws are not glogged. Cleaned the whole except the stepper system.
Now 2500 rpm idle.
Synchronized at higher rev´s

Normally there`s yellow paint on the stop screws but the lefthand is without. Yes the TPS is reset and thus fucked.

Thing on my mind is:
-Before cleaning only little issue between 2 and 3K rpm.
-Throttle body's verry dirty.
-paint removed from LH stop. (seems to be messed with)

Thing to do:
-cut of stepper system and check if lowers idle.
-new from TLM injectors but do they leak air?
-try to get a result with stopscrew (and mess furher with result of high fuelling bla bla)
-Buy a new set for the 2000. Install them and done.

Thanks steve for sharing thoughts.
When ordered a new set i can mess with the scews on the old ones for learning purpose



Think i have to replace the throttle body set.

Hi all

A simple question with a simple answer: Why did the idle speed increase? Because the engine sucks in more air.
Next question is why does it so?

Maybe the stepper - as beetle mentioned. If it is permanemtly fully open, too much air is sucked in with a higher idle.
Maybe false air from the throttle spindles. If this is the case, the stock throttle calibration is lost forever. The holy stop screw is now in the wrong position.

My 1200 Sport also suffered of a too high idle speed. When I looked at the idle steps with Guzziduag, the stepper was totally closed, the idle too high. If I remember that correctly, 50 steps is the lowest stepper position. A check of the stepper showed it works. Thats easy done - just suck on the pipe and switch on ignition. During initialisation the stepper is closed at some point.

My conclusion was the engine sucks in more air than it needs for the correct idle, thus the stepper is out of calibration as ist is already closed. Air bleed screws were also closed at that point - in case you ask.
So I took the only opportunitiy to reduce the air and closed the holy crew by 60°. I took care to do it in a way that I can return safely to the previous calibration. I also noticed the decrease in the TP voltage.

And I was successful: The idle speed dropped to the value determined by the idle speed map. When I observed the stepper figures in Guzzidiag, the stepper was open at about 100 steps, slightly varying to keep the idle speed constant. With less air in the engine, the idle stepper is back in the game and can do what it is supposed to do - controlling the idle speed.

interesting.
Today took off the stepper hose and closed it with a bolt. On the other end i closed the pivot from the air box. And yes the idle dropped sygnificant.
After TPS reset the revs went high again.

Then i turned out the lh end stop by half a turn. Rev dropped direct.
Again synchonize check and was ok.

Did NOT reset the TPS afterwards.

Now thinking: suppose i reset the TPS again and again while working with the end stop screw wich is messed whith. There must be a point where it should be at factory stage. The point where the original yellow paint was.

Am i wrong thinking?

Gave TLM a call. 2600 euro for a new set. They say, bring the GRiSO where the will adjust the existing throttlebody's to 99 procent. But what action will they do wich we can't at the GRiSO Ghetto?

Gave the GRiSO a new refreshment with MOTUL Ester oil as a present.

The thing is if you don’t re-set the TPS then the baseline is wrong. Yes, it may idle better but the fuelling and spark will be out higher at wider throttle openings.

This does concern me that the folks at TLM may not actually understand how the system works.

Incidentally, after you’ve recalibrated the TPS it should sit at 4.8. When you start the motor and blip the throttle and it idles high, what is the TPS reading? What tends to happen if the TB’s are worn is that when the engine is running air pressure on the back of the throttle plates will push them into the choke of the TB’s. If there is wear in the spindle bushes or the throat of the choke has been scalloped this will push the throttle plate slightly deeper, rotating the spindle, and therefore the TPS, slightly so the TPS value rises slightly. Any rise over a very small amount 0.2 or so, will cause the spark to start advancing and this too will increase the idle speed.

My guess is that by turning out the stop screws you are dropping the TPS value to below 4.8 so when it is *Advanced* by the movement of the plate it doesn’t get to the point where the spark advances. The same basic principle can be applied, providing the linkage rod hasn’t been messed with, by sticking a feeler gauge between the stop screw and the bell crank bar and re-setting the TPS. As explained though this will mean that both fuel and spark will be out at wider throttle openings. Enough to be dangerous? Probably not, but it’s less than ideal.

At the end of the day though it’s probably the best result you are going to get. It’s still not good though.

Pete

I agree with your comment above.
But what is the alternative? Buying 2600.- for a new set of TBs? This was never an option for me. And soon these parts will be no more available. An investment this high is not acceptible for most of the CARC bikes.

This "never touch the holy screw" thing is not applicable for high mileage bikes. As soon as wear occurs in the throttle actuation parts (spindles, stop screws etc) the calibration ist lost, if you like it or not. So we have to find a workaround to keep the bikes running with acceptible behavior.

My first 2V 1200 Sport was running like crap in the lower rpms and at idle. Idle speed was at 1100 at that point, ok but not stable. CO reading showed 0,0xxx figures - beyond the level a 2V Guzzi engine can work oroperly. Eliminating the closed loop lambda regulation did not change this. Adjustment of the CO trim setting had no influence. So I decided to increase the values in the whole idle stepper map. This worked, the engine was running with 2-3% CO, but the Idle speed increased to 2000 - 2500 rpm. The air sucked into the engine was still the same amount but now it was burning with much healthier mixture. After many tryouts to reduce the idle speed keeping a healthy mixture I ended with closing the throttles by the holy screw. The engine was now running excellent, smooth from low down to the higher revs. The crappy lower rpms were gone. The stepper kept the idle at the correct level.

Guzzidiag allows to change most of the parameters responsible for engine behavior. If carefully handled many problems can be solved and the bikes kept on the road.

Maybe we will all end with the one throttlebody setup as Beetle got.
On the other hand. Well maintained (no to much oil to keep the TB's clean) you will keep the TB good for 150K km's.
Yes a lot of money, but i can't throw the bike in a dustbin for this reason.
There should be a solution to bring the TB's to factory spec when messed with.

Unfortunately though it’s the way it is.

As I’ve said before, Michael can work seeming miracles with TB’s that are really quite messed up. Me? Not so much. I simply don’t have ‘The touch’ obviously. The fact is though even if you can get a stable and accurate idle by messing with stuff that shouldn’t be messed with once you do this the baseline for the whole map is lost so the fueling and spark are no longer going to be correct.

Now generally speaking the wider the throttle opening the less impact this is going to have overall, especially on the fueling but especially at smaller to mid throttle openings it could conceivably cause issues so care has to be taken. Yes, if you are familiar with Tunerpro and map building you could log build a map to circumvent the weirdness I’m sure but that would require a different map for every, individual, set of TB’s and motors! It’s simply not practical.

I agree with you though that these sort of compromises are going to have to be made. I’m just saying that if at all possible they should be avoided as the possibility of compounding issues and simply making stuff irrevocably worse! I can also tell you that fitting a brand new, unmolested, set of TB’s to a bike is transformative! When I did it to my bike, which was running fine but had a high idle, the effect was astonishing!

Really thought the very best way to ‘Protect’ the integrity of the TB’s and their performance is simple but often overlooked. Firstly, don’t keep overfilling the engine with oil, secondly, don’t fit a stupid air filter, thirdly, make sure the airbox is sealed and the drain hoses are attached properly and plugged. Fourthly, clean the TB’s regularly, (This becomes a less frequent necessity if you Cary out the first three steps!) and finally, tune the bike regularly. TB balance really does matter!

I'll bet TLM is doing the 9.6 reset thing. Were you back it off then reset then run screw in to 9.6