Let's set the Wayback Help request to 2000...-Update!

[paul in rochester]

I was VERY late in getting my 81,000 mile Jackal up and about this year-work was nuts. I noticed she was running kinda crummy last year, but figgered I'd get around to it this winter.
Not so much.
Anyway, she runs awful off idle when hot, snorting and garfing. Fair enough, she's overdue some work (plugs, fuel filter [last done 40k ago], setting the valves). Did all that and she still runs like crap.
My fuel mileage dropped about 20% on two tanks (from 125-130 miles to low fuel light to 99-104 miles), and the right plug's all black and fluffy.
I tried setting the TPS, but I'm damned if I can remember which two wires to check. I've tried a bunch of possibilities, but got nowhere.
The other thought about the cylinder head temperature sensor, but can't find cold/hot values.

Anything obvious (or not so obvious) that I should be checking?

Thanks!

[RinkRat II]

      Stole this from Tom's post............... ......http://archive.guzzitech.com/EVTuneup-Jeff_B.html   easy peasy

       Paul B

[pehayes]

Sounds like it is failing to detect engine warm-up and is running on the start map.

I think that model has the engine temperature sensor in the right cylinder head.  Also, I think the sensor resides in a plastic housing which heats, ages, and cracks apart.  Thus the sensor no longer makes good contact with head metal and you get false cold readings.  The replacement is a more durable brass housing.  Make sure  yours isn't loose.

Setting the TPS is important.  But, maybe you have a dirty or dead spot on the TPS internal sweep.  The device can be drilled and contact cleaner sprayed inside to clean it.  Hard to find on seat-of-pants diagnostics, but shows up on the throttle graph if you can use GuzziDiag.

See some details in this thread:

https://wildguzzi.com/forum/index.php?topic=105945.0

Patrick Hayes
Fremont CA

[Guzzidad]

    I check TPS setting by sticking a pin in Pin #11 on the plug to the ECU. Other end to ground. 157mv with throttle bodies disconnected and backed all the way off. And of coarse a throttle body balance makes a big difference.

[Guzzidad]

   Also, Guzzidiag will show you COtrim. I run mine, 01 EV, at 27, and it runs GREAT!

[paul in rochester]

Thanks, guys! This helps point me in the right direction.
When I saw the plastic base for the head temp sensor, I was afraid to touch it. I thought that, after 20 years, it would just fall apart and I'd be up a creek. I'll look for the brass replacement...if it's till out there.

I'll work on this when I'm back in!

Paul

[guzzisteve]

You may need to clean the throttle bodies, not just the throat & butterfly but the bypass air screws also. If blocked they turn your plugs black.

[Vagrant]

worth checking the cam position sensor to. also make sure a mouse didn't set up home in the air intake or filter housing.

[paul in rochester]

So-o-o-o,
I was able to get to and check the TPS. I'm getting 1.29v at idle.
Yeah, it's a bit more than it should be.
So I'm now researching new a new TPS. I can't really gripe-20 years isn't terrible.

Thanks for the help so far...

Paul

[guzzisteve]

I would think you just adjust it a bit first to the right setting before swapping it. You have to adjust the new one after it's screwed in place.

[Vagrant]

it's always worth removing and flushing with contact cleaner first. but after 80000 and 20 years you should be buying #2 or 3

[BillinPA]

If you are having trouble ironing it out, I am not close Beaver Falls, PA. But if you can get the bike here, I am fairly confident I can get it running well.

[paul in rochester]

OK, so I finally got time and picked up the new TPS. I set it via Wayne's method; the 'official' way looked rather fussy. I also bought some copper anti-seize (hard to get, and pricey!) and put a dollup on the engine oil temp sensor on the right head (which, by the way, came right out WITHOUT the plastic holder disintegrating!)

I also replaced both intake boots between the TB and the head. The bike backfired out the left intake a few months after I got her (brand new), blowing the intake off, tearing the boot. We were on a trip and it didn't look like it had torn into a critical area, so I just slapped it back together. When I got back , the dealer said not to worry about it, and that the boots were backordered anyway. I finally decided that I should replace the both of them after this much time.

Gas mileage picked up, and she idles and runs smoother. The only thing that I have now, though, is she is backfiring through the left intake when hot on small throttle loads, like pootling through town on a hot summer day (like today). It makes slow riding very challenging.

Otherwise, things are much better.

Thanks again, guys, for the ideas!

Paul

[paul in rochester]

A year later, and here goes...
So, after setting the TPS and balancing the throttle bodies, etc, she ran fine.
And then she didn't. It almost seemed that the settings were changing on a mile to mile basis.
After spending all summer fussing with it, I threw in the towel. I took her down to Hamlin Cycles in Connecticut this spring. I'm stubborn, but even a year of messing with it had me to the point of no return. It's not even a bad drive; from here, it's four and a half hours or so, doable in one day.

End result was the pivot shafts for the throttles themselves were wearing oblong holes in the throttle body housing. Track down a used throttle body assembly, install and adjust, and Bob's yer uncle. I would never in a gazillion years have found this. Apparently, it's a Thing on older high mileage bikes. She is so much smoother now, and behaves at small throttle openings. I can easily see another twenty years at this point.

Of course, many thanks to the folks at Hamlin. Nice to talk to and work with.

[kingoffleece]

Yep.  Jimmy Boy and the crew really know their stuff.............. .......

[moto-uno]

  Must say it's heartening to hear good reviews about a Guzzi dealership    . Peter