Author Topic: Uh, oh... Think I may have fried the ol' bike brain... ('97 Sporti) SOLVED (Read 4770 times)

QCGoose · « **on:** July 18, 2016, 06:08:39 PM »

Last fall, we were in the process of moving and I wanted to ride my bikes over to the new house before the snow flew instead of messing with the trailer (the garage was full and the trailer was practically buried). The Cali, no problem, but my Sporti's battery was dead and wouldn't take a charge overnight with the trickle charger, so I attempted to jump it with my truck, not knowing that it was a HUGE NO-NO and could end up frying the ECU. Once I disconnected the jumper cables, the bike would continue to idle but then die about 10 seconds later. So in the end, I ended up trailering it anyways.

Fast-forward to a week or so ago and I finally have time to do things so I start messin' with the bikes and order a new battery for Ol' Yeller. It arrived last week and I hooked it up on the trickle charger overnight so it's definitely fully charged, and when connected to the bike with the ignition on, everything lights up (all dash lights, signals, brakes, etc work), but the fuel pump doesn't prime when I switch to "Run" and when I hit the starter, it spins with what sounds like a very "healthy" RPM but doesn't engage the engine.

Also, with the battery connected to the bike, neither one of my chargers "recognize" that they're connected to the battery, but when it's out/disconnected from the bike, they both recognize and charge the battery. No clue what's goin' on there.

I have no clue about the relays, but all the fuses look good, including the one for the fuel pump.

Any ideas? Or am I SOL and just need to start looking for a new ECU?

Kiwi_Roy · « **Reply #1 on:** July 18, 2016, 06:57:06 PM »

First of all check you have the battery the right way around, the ECU won't engage if you have it wrong, everything else will work though it may crank backwards depending on the make of starter.

The chargers often won't recognize a battery if it's flat and certainly won't if it's backwards.

The fact that it started and ran when you jumped it last year it could just be a flat battery, the FI bikes are a bit fussy that way.

fotoguzzi · « **Reply #2 on:** July 18, 2016, 07:06:41 PM »

Oem relays? I'd get new relays from dpguzzi.com replace them all for $20.
Next are you sure all (3 ?)positive cables are connected to battery? Clean and tight?

tazio · « **Reply #3 on:** July 18, 2016, 07:46:20 PM »

She's toast. Let me take it off yer hands...

QCGoose · « **Reply #4 on:** July 18, 2016, 09:31:35 PM »

Quote from: Kiwi_Roy on July 18, 2016, 06:57:06 PM

First of all check you have the battery the right way around, the ECU won't engage if you have it wrong, everything else will work though it may crank backwards depending on the make of starter.

The chargers often won't recognize a battery if it's flat and certainly won't if it's backwards.

The fact that it started and ran when you jumped it last year it could just be a flat battery, the FI bikes are a bit fussy that way.

Well, I hate to share with the world how scatter-brained I've been lately because there has been so much going on with my home and work life, but you were exactly right. The battery... was in backwards.

I thought there was absolutely no way in the world I could have overlooked that; something so simple, and something so stupid lol. But I went out to the garage and sure enough, there were the plus and negative symbols with the wrong cables attached. I was so certain that I fried the ECU since I tried jumping the bike last year that I didn't even think about the battery connections, especially since I placed the new battery in facing the same way as the old battery (and it's the same battery as the old one as well).

Well, I'm so incredibly relieved that my own stupidity was such an easy fix. She fired right up afterwards, purred like a kitten, and ran flawlessly for a bit over an hour ride.

Do you take donations, Kiwi?

QCGoose · « **Reply #5 on:** July 18, 2016, 09:35:03 PM »

Quote from: fotoguzzi on July 18, 2016, 07:06:41 PM

Oem relays? I'd get new relays from dpguzzi.com replace them all for $20.
Next are you sure all (3 ?)positive cables are connected to battery? Clean and tight?

They were, but I did clean them just to be sure lol.

Quote from: tazio on July 18, 2016, 07:46:20 PM

She's toast. Let me take it off yer hands...

Sorry, good sir, but she's a keeper.

oldbike54 · « **Reply #6 on:** July 18, 2016, 09:57:32 PM »

So it turns out it wasn't the bikes brain that was fried

Dusty

QCGoose · « **Reply #7 on:** July 19, 2016, 06:00:40 AM »

Quote from: oldbike54 on July 18, 2016, 09:57:32 PM

So it turns out it wasn't the bikes brain that was fried

Dusty

That was my exact thought once I saw my mistake.

twhitaker · « **Reply #8 on:** July 19, 2016, 06:01:38 AM »

Thank goodness for diodes.

Kiwi_Roy · « **Reply #9 on:** July 19, 2016, 06:41:10 AM »

It's very easy to do, the good list of symptoms gave me a clue, any time the bike will crank it should have power to the ECU relay.

Yes, thank goodness for the safety diode, wouldn't want to go 50 MPH backwards

Kev m · « **Reply #10 on:** July 19, 2016, 10:46:06 AM »

Wait, so a charged battery was installed backwards and DIDN'T fry the ECU? What protected it? Diodes where?

Kiwi_Roy · « **Reply #11 on:** July 19, 2016, 04:42:32 PM »

Quote from: Kev m on July 19, 2016, 10:46:06 AM

Wait, so a charged battery was installed backwards and DIDN'T fry the ECU? What protected it? Diodes where?

Here's one you are familiar with Kev. item 51 Safety Diode
http://www.thisoldtractor.com/guzzi007/schematics/2000_Jackal.gif
It prevents the ECU relay from picking up
The P8 ECU has one also but it's inside
~~I would guess the later models have them also but I can't verify it.~~
Here you go, the V7 has one inside the relay itself (item 11), I prefer the Jackal way myself, no special relay.
http://www.thisoldtractor.com/guzzi007/schematics/2008_V7_Classic.gif

tazio · « **Reply #12 on:** July 19, 2016, 06:12:45 PM »

Whew! Close call young man

Kev m · « **Reply #13 on:** July 19, 2016, 06:15:53 PM »

Quote from: Kiwi_Roy on July 19, 2016, 04:42:32 PM

Here's one you are familiar with Kev. item 51 Safety Diode
http://www.thisoldtractor.com/guzzi007/schematics/2000_Jackal.gif
It prevents the ECU relay from picking up
The P8 ECU has one also but it's inside
~~I would guess the later models have them also but I can't verify it.~~
Here you go, the V7 has one inside the relay itself (item 11), I prefer the Jackal way myself, no special relay.
http://www.thisoldtractor.com/guzzi007/schematics/2008_V7_Classic.gif

Tom · « **Reply #14 on:** July 19, 2016, 06:41:21 PM »

So the bike fires up and runs?

Maybe.

Kiwi_Roy · « **Reply #15 on:** July 19, 2016, 08:57:45 PM »

Quote from: Tom on July 19, 2016, 06:41:21 PM

So the bike fires up and runs? Maybe.

No, it won't fire up with the battery in backwards, the ECU doesn't even get power, fuel pump and ignition coils stay dead.

Tom · « **Reply #16 on:** July 19, 2016, 09:00:41 PM »

I should have added "after putting the battery in correctly?"

QCGoose · « **Reply #17 on:** July 19, 2016, 09:07:58 PM »

Quote from: Tom on July 19, 2016, 06:41:21 PM

So the bike fires up and runs? Maybe.

Yes sir, she runs flawlessly.

Tom · « **Reply #18 on:** July 19, 2016, 09:22:42 PM »

You took it out for a ride? after the the battery was installed correctly and it started then was running.

News:

Author Topic: Uh, oh... Think I may have fried the ol' bike brain... ('97 Sporti) *SOLVED* (Read 4770 times)

oldbike54

Author Topic: Uh, oh... Think I may have fried the ol' bike brain... ('97 Sporti) SOLVED (Read 4770 times)