2001 California Special popping...driving me nuts

[Luap McKeever]

This bike is driving me nuts.  It's my wifes and it's popping so often it's becoming dangerous to ride.  Here's what I have...

15M computer. New TPS. Fresh valve adjustment. New spark plugs. Thottle bodies cleaned.  Throttle body boots ok.  Running 91 octane.
Spent money on cables for Guzzi Diag.  Have tried setting throttle to 3.6 and makes it worse.  Put it back to 5.48 and it's better but still pops.  Tried adjusting CO trim and it wont stay where I put it.

Oddly enough, I cannot set the idle.  Have tried adjusting both ways until I'm blue in the face.  Stays around 1300 RPM no matter what.

So, at this point, I am officially a dummy. So, please treat me like one.  What can be the problem.

[Rich A]

Ignition wires & caps?

Rich A

[Luap McKeever]

Ignition wires & caps?

Rich A

Well low and behold, I made one final small adjustment and it's running perfect now. Still cant get the idle to come down though.  It's holding around 1250-1300 RPM.

But, new wires probably would be a good wintertime project. Thanks for the reminder.

[beetle]

What was the final small adjustment?

[fubar guzzi]

Laup is a dummy-------Luap is a dummy---------------Luap is a dummy hope you feel better now!!!!!! But we all still love ya anyway

[fotoguzzi]

What are the air bleed screws set at?

[rodekyll]

Yes -- what was the adjustment?

Also, what is the high idle cam and linkage looking like?  It might be holding the throttle slightly open.

[Luap McKeever]

What was the final small adjustment?

Put it back to 5.48.  Ran terrible at 3.6.  Something else must be amiss, but at least it's not popping now.  BTW, This is a HD TPS, so that might be the reason it will only run right at 5.48.

What are the air bleed screws set at?

Huh?  I have never messed with them.  Maybe I need to play with those next...

Yes -- what was the adjustment?

Also, what is the high idle cam and linkage looking like?  It might be holding the throttle slightly open.

They look normal to me.

[OlDogface]

Laup is a dummy-------Luap is a dummy---------------Luap is a dummy hope you feel better now!!!!!! But we all still love ya anyway

Laughing!

[Tom]

The contacts in the TPS need to be de-gunked.

[Chuck in Indiana]

Huh?  I have never messed with them.  Maybe I need to play with those next...

Uhhh... you're having a lean problem and fast idle problem and don't know where the air bleeds are set? 

[beetle]

Did you check out that link I sent you?

[guzzisteve]

You may need to take out the air bypass screws, shoot some carb cleaner up the passage ways, clean the goo off the screws & re-install @ 1/2-3/4 turns out. I blow air up there also just to make sure it's cleaned out.
I do this ea time I clean the TB's. Then start syncing the TB's
Back off the screw on the center cam that is for the high idle lever so you have play. It faces the RH side and has yellow paint on it.
I have also seen the CO trim on the 15M ECU reverse itself from + to a - at least 3 different bikes.

[Luap McKeever]

Uhhh... you're having a lean problem and fast idle problem and don't know where the air bleeds are set? 

Correct.  I figured they haven't been touched in almost 70,000 miles so how could that be a problem?  I guess I'll need to do some homework.

Did you check out that link I sent you?

Yes but I need to revisit it tomorrow.  My brain is mush right now.

[Rich A]

Correct.  I figured they haven't been touched in almost 70,000 miles so how could that be a problem?  I guess I'll need to do some homework.

As I recall, I removed a set of bleed screws from one of my bikes and they were filthy with brown goop.

RIch A

[ccoli]

Set my pals valves and it quieted down a lot.  I like the popping,. Deer don't like that sound !

[Luap McKeever]

Set my pals valves and it quieted down a lot.  I like the popping,. Deer don't like that sound !

This is not your normal decelleration popping. This is like a sneeze/hiccup.  I can even see the entire right hand throttle body move a good 1/8" when it does this.

[Dukedesmo]

This is not your normal decelleration popping. This is like a sneeze/hiccup.  I can even see the entire right hand throttle body move a good 1/8" when it does this.

Lean mixture backfire, if you look you'd probably see flames shooting out the intakes.

When I had my Ducati 916 heads gasflowed it did this on first startup, the throttle 'butterflies' were being knocked all over the place by the short flames being shot out. Had to add significantly more fuel just to get it running smooth before taking to the dyno.

Quite disconcerting when you think that the top of the airbox is the underside of the fuel tank...

[rodekyll]

Luap, what you're describing sounds a lot like either a faulty injector or a significant vacuum leak on the right side. 

Even if the guzzidiag/vdsts/whatever says the injector is working, it can't tell how well or how much it squirts fuel.  All it knows is that a signal was sent from the ecu and the injector solenoid responded to it.  You can pull it and check it for flow and volume easily enough.  Look for ~100cc/30sec, a clean 'cone' of spray, and an immediate shutoff with no drips.  Grab one of those 12v power supplies you're buried in and make the tester.  . .

A vacuum leak should be easier to sort out.  The intake rubber boots are directional -- they have a tongue and groove arrangement that gives a positive seal/grab on the manifold runner and the TB.  Reversing it or not getting the grooves and lands in place will cause a vacuum leak and also the visual movement of the TB when it backfires.  Overtightening the band clamps will cause leaks, too.  Judicious squirting of something like WD40 around the boot joints can help identify that problem.