One Last try

[Guest hogjockey]

OK today I got the guzzi out and decided to take a 100 mile run on the innerstate.

Here were the MPG results. running 65 to 80 MPH I got a total of 25.41 MPG.

At 60 it still had a surge and under med to hard excelleration it would miss a bit.

Arriving back to the shop I pulled the plugs and the left side is burning cocoa. However the right side is very black and sooty. Not wet but very black.

 

So tomorrow it all come apart and i check and recheck everything one last time.

I am going to pray to the Guzzi Gods tonight for wisdom....lol . I just think it has got to be a sensor or a short or a something........ Wish me luck and as always

any help is appreciated.......Tony

[txrider]

Hog, sounds like it could be the temp sensor, doodad sticking out of the r/h cylinder head. Bad sensor, ECU thinks engine is cold, running in warmup mode.

[Keith Foster]

25.4 is very low mileage. I've been getting in the low 40's since new ('04 Nero). txrider may be on to something. There must be something amiss to be using so much fuel.

[Guest hogjockey]

Hog, sounds like it could be the temp sensor, doodad sticking out of the r/h cylinder head.  Bad sensor, ECU thinks engine is cold, running in warmup mode.

55355[/snapback]

 

I agree but cannot seem to figure a way to check the values.

But at this point I agree with you , but why only the right cylinder?

[Steve G.]

You say that one plug is brown, one sooty black. So, I would think this fact would rule out any shared components the two injectors deal with. Which means it is not the ecu, any sensors, etc. I think it is the injector itself, or a component which services one single injector.

Try changing the injectors over, left to right, and right to left. New plugs, and see if the sootiness changes sides. It's not the first time.

Ciao, Steve G.

[big J]

Fair play to you Hog, you're demonstrating the same determined, stubborn, sheer bloody mindedness to fix the thing that Guzzi owners are famed for"it's an old fashioned air cooled twin, I'll get it going, now hand me that hammer and chisel, Ethel, and read the bit about diaster adjustment again."

Personally, and not to doubt for a moment your prowess with a spanner, I'd go right back to basics first. Valves, TPS, sync tbs. Are you using gauges to synchronise the tbs? If so, have they been calibrated? Have you done a compression test? Are things like the HT leads, coil wires etc ok. Work to the KISS principle, and if you swap over anything right to left, do it one piece at a time and check. It almost sounds like this is going to be one of those problems, that when solved everyone goes "of course, I was just going to ask if you'd checked that". Keep plugging away at it, you'll get it!

[callison]

I think I'd just try a new pair of plugs first as well as set the valves correctly. This follows the KISS philosophy and costs next to nothing. If results don't improve or at least point to something more specific - then - start the more complicated gyrations. If you have a good dealer, you might just want to let them do a good tune-up first and establish a baseline for your bikes behavior.

[jrt]

Check the balance between the throttle bodies.