Jimbemotumbo's V11s EFI tune from hell

[jimbemotumbo]

Sorry for the length, but many of you know how long I've spent fooling with this, and quite a few have had a hand in giving me advice sufficient to finally fix it. So here it is:

 

You will recall the following:

- Significant miss and hesitation at 3k rpm

- Poor starting

- "Carb" farts at various throttle settings

- Surging and sputtering worsening over time

- Unrideable bike

 

Based on input from this board I went through valve adjustments (I'm really good at this now!), TPS settings, a new fuel filter, new wires and plugs, many PCIII maps, a new manual petcock, checked wiring, relays, fuses, etc. I even swapped the TPS for a Harley unit.

 

After all this ....

The problem turned out to be nothing more than basic EFI setup!!!

At the end of this post I will give you the step by step TPS process that worked for me.

 

I appreciate the time many have taken to post this adjustment process, both here and on guzzitech. I found literally dozens of explanations. Either I didn't read them correctly, or each one was missing some important bit of info. *I admit to being a bit dim* It all came together for me when I followed a link from this site to a general FI adjustment page for BMW, Ducati, and Guzzi. There I found the missing philosophical bit I needed to understand what I was doing wrong. This is:

 

TBs must be completely isolated from each other, and adjusted to operate identically, but separately. This was the key.

 

After using this new procedure, the Goose now starts easily, idles well, and pulls like a train through the entire power band. Not a single miss, hiccup, or flaw anywhere.

 

The jimbemotumbo version of the efi setup follows. Now that I understand it, it might take 30 minutes start to finish. This procedure combines elements of all of the other threads and procedures I found (thanks to all you authors and contributors). I hope this helps everyone else with this problem (I know you are out there!). While you are at it, go ahead and check your valve adjustment, wiring connections, relays and such, before you set the TPS.

V11s EFI SETUP

 

1. Disconnect the throttle linkage on the left TB, the fast idle lever on the right TB (remove small circlip underneath and tape it to your forehead), and the balance shaft at the right TB (the ball and socket connector). Everything comes off! This is criticial. Air bleed screws should be screwed in all the way. *My first adjustments failed because I left the choke cam connected. Connected tps voltage was 150 exactly - disconnected it dropped to 70*

 

2. Back out the right and left throttle body throttle stop (idle) screws so they do not touch the tabs.

 

3. Check that each butterfly is fully seated.

 

3. Turn on the ignition (motor not running) and set the TPS voltage to 150mV. Get this as perfect as possible. I found TPS voltage measured any other way to be of no help at all. I'm sure +/- 2 mv isn't a big deal, but I took the extra few minutes to get it dead on.

 

4. Adjust idle screw on the right TB so that the TPS reads 500-525mv. Remember - everything is still disconnected from the TBs!

 

5. Try to keep track how far you've turned the stop screw to achieve the voltage above. You want to turn in the left TB stop screw the same amount. This is approximate at this stage.

 

6. Start it up! The idle will be a bit low and uneven at this stage.

 

7. Open air bleeds on both TBs to get it to idle at appox 1100 rpm. Guzziology says these should be 1/2 turn open. Mine ended up a bit less than that. Yours may be higher. Use whatever setting gives you the right idle.

 

8. I used the balancer at this point to ensure each TB, with air bleeds adjusted, was balanced. I think my left TB air bleed was slightly more closed than the right. The TBs are now independantly operating in harmony.

 

9. Hook everything back up. I adjusted the balance shaft so that the socket lined up perfectly with the ball on the right TB (nothing moved when I slipped it on). Make sure you put the fast idle cam thingy back on. Hope you didn't lose the circlip!

 

10. Start her back up and sync the TBs using the white knob. Guzzi motor nirvana is now achieved.

 

These are such wonderful bikes when everything is perfect. I will nail polish all the adjustment screws so hope fully won't have to do this again. Easy now that I've done it right once.

 

Thanks again to all for their advice and understanding. What a great resource, this web site! Saluti

[txrider]

Thanks for taking the time/effort to add your experience on what works to the FI tuneup. I am about to do this and your procedure is what I'll use. I had the basic approach down but several points you added will help a lot.

[Guest ratchethack]

This is as simple and straightforward a write-up as I've seen. After using a combination of several other procedures over the past few years, parts of which I either couldn't make complete sense of, or just plain didn't work well for me, what you've written matches up with what I've found to work well also.

 

It's a wonderful thing when you get it right, innit?

 

Well done! Glad you hear you finally conquered your demons, this'll no doubt help others!

[Ouiji Veck]

Dam good job of explaining this procedure in a straight forward

and understandable way. Copied and pasted into my glitches and fixes library.

You Da MAN! Yea this board is great.

 

Next chore is to find posts for stealing some juice from the charging system for

heated grips and vest (October!!) and halogens...or a white cane...

Sheesh...I thought Lucas was the prince of darkness.

[Mr. Bean]

Sounds like you and I were fighting the same battle at the same time and both came up with the same solution at the same time....Although I beat you by a few weeks!

 

I too discovered that doing EVERYTHING disconnected on each TB is the key to getting the balance spot on. I was fighting an issue that no matter how well the TBs were synched at one rpm, whether it be idle or 2000 or 3500...it would be out of synch somewhere else. By taking the time to adjust the length of the rod between the two throttles, it really is possible to get it within 1/2 on the Twin Max throughout the rev range.

 

Randy