Bike cuts out / dies at 6k rpm? Electrical issue?

[Guest bmonnig]

Guys,

 

I just took my Sporti out for it's first test run after replacing the rear drive. Good news: It appears the new (used) rear drive works fine. No noticeable oil leaks, and it seemed to run fine. I'll keep an eye on it to see if any leaks develop, but it looks to be good for now.

 

Bad news: The bike has developed some sort of an electrical gremlin. Initially, I felt a hiccup when accellerating hard. As the tach swung past 6k, the bike suddendly 'shut down', then came back. I almost thought I hit the rev limiter, but it was a bit too harsh and lasted too long for that. I continued the ~6 miles to my destination.

 

On the way home I started testing some more. Hard accelleration, and sure enough, between 6-8k the bike would hiccup 'shut down'. It appears to be electrical in nature, as the tach dropped to 0 even though the bike was still turning good RPM's (still in gear, being turned over at highway speeds).

 

I continued testing this as I got closer to home. Eventually, as the bike passed 6k-6500, it would cut out completely. I pulled to the side of the road, popped the pass seat, and wiggled the fuses / relays. Bike fired right up.

 

Back out on the freeway, rev it up, hits 6-7k, and dies again. Back to the side of the road within a couple hundred yards of my last spot. Pull rear seat again, but try to re-start WITHOUT touching any of the electricals. Starts fine. This leads me to believe it's the reset action of the ignition that clears the problem, NOT a physical connection with a relay / fuse.

 

Test out this theory a few more times in the short distance home. Below 6k, seems to run fine. Above 6k, it'll cut out and die. Pull to the side of the road, shut off the key, re-fire, and the bike runs fine. Very repeatable.

 

Any ideas on this issue? It's not just a 'miss'; rather, the ignition does completely. It's worth noting that the gauge lights (neutral, oil, etc) will stay on, although the tach drops to 0.

 

Would this be a symptom of a dying relay? Dying CPU? Something else? Anyone had this sort of a symptom before? The bike didn't exhibit this symptom at all during the 250 mile ride a few weeks ago (when I noticed the cracked drive hub). I've since pulled the front and rear fairings. While I don't THINK I disturbed any connections, I'll pull them again to re-check.

 

In the meantime, I'm open to suggestions.

 

Thanks,

 

Brandon

 

******EDIT******

 

Per Carl Allison's suggestion, I added an additional ground wire for the reg/rec, as well as running additional grounds to the gauges. This did not fix the problem:

[Guest bmonnig]

Carl,

 

Thanks for the info! During the night I pulled the tank and tail fairings. I ran a suitable gauge wire from the regulater back to the ground strap on the battery. I figured this 'direct' connection would probably be better than using a possibly corroded connection on the engine. My Honda VFR is known for reg/rec issues as well, and adding ground / + lead wires to that bike is common, too. On the Honda the ground isn't added from the case, however; it's spliced into the actual ground wire on the reg/rec. I didn't notice a ground wire on the Guzzi unit, so I suspect it's grounded solely through it's casing?

 

As mentioned, I ran a grounding wire from the regulator casing back to the battery ground strap. I also ran 2 wires (one each) from the regulator casing up to the gauges. While I didn't check in the manual, I connected the two grounding straps to the posts (1 each) on the rear of the gauges. They currently have 1 wire running from them. These are also the post used by the upper-most rubber isolators.

 

I was hoping to fire the bike up, take it for a quick test ride, and find everything had been fixed. I'm just dying to ride this bike more, and I REALLY wanted to take a nice bimble around the Santa Monica Mountains and ??? today. Unfortuntely, that doesn't appear to be in the cards.

 

I fired the bike, and took it for a quick around-the house test run. Initially everything looked fine. I pulled right up to 8k, and seemed good. Then, however, it hit. At the 6k mark, the bike would just die. I didn't even pull over...pull clutch, click to neutral, turn key off, turn key back on, and re-fire. Bike fired fine as I was still rolling.

 

Additional tests showed the bike doing the same thing repeatedly, right around the 6k mark. Once or twice as low as 5500, once or twice as high as 6500-7k. But it died in that zone each time. As I found yesterday, it would always fire up and run afterward.

 

I did notice while letting the bike warm up that it appeared to be running a bit rough, and / or possibly below the idle rpm I'm used to. It also died once, for no apparent reason (while warming up). I realize the big-jugged twins are somewhat cold natured, and a misfire can cause them to die at low rpm. Something about this stall just didn't 'feel' right, though. It was idling ok previous, and then WHAM...it instantly died. It fired right up, and continued idling. The idle just felt, for lack of a better term, weak somehow.

 

Anyway, I'm open to suggestions. This is really puzzling, as the bike exhibited NONE of these problems the last time I rode it (what...a month ago?), prior to the rear-drive issue. I swapped the rear drive box, and pulled the front fairing to replace an indicator housing. Aside from that, I've not really done anything with the bike.

 

A quick visual inspection shows good battery connections, good computer connections, etc. Indeed, ALL the connectors I can see appear to be in good condition and making a good connection.

 

I'm really not sure where to go from here. I'm reminded of a ZX9 I once owned, that had bad coils. The bike would run fine at idle, but as soon as a load was added it would start to run like crap. Finally, after replacing the coils, it ran fine.

 

What are the symptoms / failure modes for a Guzzi if:

 

1) Relay/s are failing

2) Computer is failing

 

Would these items be culprits with my current symptoms, or probably not?

 

I'm certainly open to all suggestions or ideas.

 

Thanks,

 

Brandon (really bummed about a Goose-free Sunday ride)

[big J]

Possibly a dumb question, but there's no chance this is fuel related? Does the computer have a way of shutting down the ecu if it detects too lean a mixture? Alternatively, if the reg/rec senses overcharge from generator, could this shut it down? Just a couple of stabs in the dark, I'm afraid.

[callison]

Brandon (really bummed about a Goose-free Sunday ride)

 

I hear ya Brandon, I'm likewise bummed about no Guzzi for the moment. We need to combine engines - mine won't run below 6000 rpm and yours won't run above...

 

My problem is supposedly the cam chain tensioner, but I won't know until I move into my next house and the eventual Guzzi work period gets scheduled. FWIW, my Sporti has 60,000 miles and has run like crap for the last 13,000 of them. At this point, I've logged a whopping 140 miles on it in 3 years! Very disappointing. When they run, they're great. When they're recalcitrant, they are unbelievably bad.

 

It's odd that yours would run to 8000 rpm once and then not again. I suppose the next place to check would be in the wiring harness underneath the power relay. Look for a single bullet connector buried in the wiring and pull it apart and re-seat it a few times. That was my problem once (in a driving rain with a 3 mile push to ensure a positive attitude when I got to the freeway off ramp). I won't go into the explanation of why that one was errant at that time. The second place might be the coils. This is all rpm dependent which makes it doubly hard to diagnose. My V11 Sport blows the ECU fuse every time I whack the throttle open when I'm riding. In the garage or on a stand in gear, I cannot get the fuse to blow, so I have a more than sincere appreciation of your problem.

[stormsedge]

Brandon, I had some similar symptoms that I was convinced were electrical and later found was the heat refelctive sheilding on the bottom of the gas tank getting sucked down onto the open air filter above 5K rpms, effectively cutting off the air...do you have an open airbox? If so, take a look under your tank. k

[Guest bmonnig]

Brandon, I had some similar symptoms that I was convinced were electrical and later found was the heat refelctive sheilding on the bottom of the gas tank getting sucked down onto the open air filter above 5K rpms, effectively cutting off the air...do you have an open airbox?  If so, take a look under your tank.  k

55457[/snapback]

*****

 

K,

 

Thanks for the thought. I'm still running the stock airbox, with the stock lid / snorkels.

 

Thanks,

 

Brandon

[Guest bmonnig]

FWIW, I just checked the resistance on both crank sensors; red bike (problem bike) = ~691 ohms. Yellow bike (runs fine) = ~697 ohms. Unless I need to check these in diode mode or something, I think the crank sensor may just be fine. I'll try to swap the computers between the bikes and see if the problem stays, or switches bikes.

[Murray]

Stupid question but have you run a spanner over your battery terminals recently also the bolt that holds the earth strap on the frame. The carbed 1100 sports mange to vibrate them loose occsionally.

[Steve G.]

I've hit the rev limiter a couple times, and this Marelli CPU does take 2 seconds to "re-ramp", just as when you start it up. Why yours is shutting down at 6000rpm is a question for an electrical engineer, as most electrical components are re & re units, not servicable.

Ciao, Steve G.

[mikie]

I too had the same problem last year, with the bike cutting out between 5-6000 rpm, and it turned out to be a loose connector to the fuel pump relay. As Carl suggests, pull the harness below the relays and check the connectors carefully.

[Guest bmonnig]

Well, I mounted tires on the yellow Sporti this morning, dropped the front on the forks a bit, and swapped computers with the red Sporti (problem bike).

 

Info: The yellow bike has a stock computer / chip, with a full Staintune system. It has the stock airbox, but I don't know if the lid is on it or not.

 

The red bike has a stock computer, with an UltiMap chip. I don't know the mapping, but I guess it's set up for the exhaust, which is stock (including the colostomy bag) w/ Mistral slip-ons.

 

Total miles put on yellow bike for test ride: 17.6. The first 4 miles or so were on surface streets through town. The 'cutting out' electrical gremlin didn't present itself, though the bike was kind of running like crap (lots of backfiring, etc). I guess this would be due to the mapping on the UltiMap chip, though the yellow bike runs fine w/ a stock chip. That's a bit odd, as I'd expect it to run at least a LITTLE better with a mapping for a slip-on.

 

I ran the bike to redline a couple of times. Sometimes slowly, sometimes with a quick burst of accelleration. Each time it would hit redline with no issues. "Not the computer", I thought, which seemed to be good news.

 

To get some road speed testing, I headed over to the freeway for a long-ish route home. First 8 miles or so were fine. Lots of popping on decel, and running a bit rough, but not cutting out. Cruised at speed ok, and took the bike to redline again via slow and fast methods. About 4 miles from home, though, things got ugly.

 

Pulling onto the freeway from an interchange, teh bike had a bit of a 'hiccup'. It died momentarily, but then came back. This was EXACTLY how it felt before, though it would usually die completely. Well, I wasn't disappointed. In that last 4 miles between the interchange and my house, things got UGLY.

 

In that time frame the bike started running HORRIBLY, and died probably 25 time. Unlike the previous incidents, these 'cutout' incidents were all over the board. It would die at 3k rpm, and it would die at 6k rpm. Sometimes pulling in the clutch and revving would bring it back to life, sometimes it wouldn't. Sometimes it would die while under load (accelerating), sometimes it wouldn't. Sometimes it would run for 50 yards, sometimes I couldn't even get the clutch back out before it would die again.

 

Things I noticed: Gauge lights were on when the bike died. Tach went to zero, even if the engine was spinning (in gear, at freeway speed with no ignition...engine being driven by the rear wheel / tranny). The starter would work after the engine died, but the bike would not re-light. The ONLY way to get the bike to re-start was to turn the key off, then back on again. Generally the bike would always fire after doing this, but the run time was all over the board. Sometimes it would just rev up and die, sometimes it would run / pull normally for a couple dozen yards.

 

Unlike the failure on teh red bike, which seemed to be very focused, the failure on this bike seemed to be all OVER the place, and rendered the bike unrideable. Oddly, the first 12-13 miles of the test ride were completely problem free, aside from the generally poor running and backfiring. That last 5 miles, though, was a nightmare.

 

I guess I need to swap the original computer back in the yellow bike, take it back out, and confirm it runs normally again. I should probably also run the red bike (initial problem bike) with the yellow bike's stock computer. I'm guessing the red bike would run fine that way, but I'm afraid whatever cooked teh red bike's computer may cook the yellow bike' s computer as well.

 

At this point, I'm leaning towards some sort of weird computer failure. The yellow bike has been running fine (well, normal for a stock computer) until today, after swapping in the computer from the red bike. The first 12 miles after the swap were crappy (but cutout free); then it became a nightmare.

 

What else would there be to check? I think ideally I'd:

 

1) swap yellow bike computer back into yellow bike. Confirm bike runs normal again

 

2) put yellow computer in red bike. Guessing this would cause the red bike to run fine, but afraid of killing the yellow computer (if something on the red bike killed the red computer).

 

Are there any 'common' failure modes for this computer? Does this completely wigged-out situation sound / feel like a computer failure?

 

I'm headed back out to the garage to swap computers back over. Hopefully the yellow bike will be back to running fine. I'll post the results.

[jrt]

My first thought would be that the computer is losing power somehow. Check the connections before you swap them again.

If it is the computer: Some random electronic thoughts and questions- how hot was the comp. before it started cutting out? It could have taken ~20 minutes to get it up to temperature and exhibited this behavior.

Can you open the ICU up? If so, you can test the components, but first off- look at the capacitors in there and see if the magic smoke came out of one. Tell-tale sign for cap failure is that the cap is 'bulging' and there may be some oily residue at the base. You might need a magnifying glass if your eyes are as good as mine.

[Guest bmonnig]

Well, the electrical mystery appears to be solved.

 

Obviously, this seemed to be a computer problem, as the issue 'followed' the computer from bike to bike. After reading the suggestions from several Guzzi sites, I was curious about the computer. Specifically, I was curious to see if there was a bad solder joint, and or a toasted component. So I went downstairs early this morning to pull the cover off the computer and take a look.

 

Prior to removing the cover, I inspected the circuit board through the 'inspection hole' in the top (I used a flashlight). While doing this, I heard the faintest 'tink tink' of something rattling around -inside- the computer. That's not good. :? Yep, time to take the cover off.

 

I pried off the lid, and gained access to the board. At first glance, everything looked fine. No hint of a blown component, lifted trace, loose connection, etc. I inspected the whole board, paying particular attention to the connector joints and the heat sink joints. Everything looked fine.

 

I did find the source of my 'tink tink' rattling noise, though: It appears part of the chip slot / housing cracked. The black plastic that composes the exterior of the chip slot? The 'holes' that the chips metal 'legs' slide into? Well, small sand-sized bits of plastic appeared to have broken off of the housing around the two 'front' holes. I found the small bits in the housing and cleaned them out.

 

I also noticed that I seemed to be able to see an AWFUL lot of the 'legs' of the chip adapter plate. (This computer has an UltiMap chip, which apparently uses a PC board 'adapter' plate to fit the stock chip slot). I decided to wiggle the chip slightly, just to see if it was at all loose. I put the end of my finger on the chip, and just STARTED to apply presure to lift / wiggle the chip. I can't express how little pressure I applied, and the chip just lifted right up! D'OH! Apparently the chip wasn't inserted properly by the shop, and / or it somehow worked itself loose.

 

I pulled the chip out (which didn't require any effort), and inspected the chip (with adapter PC board) and the slot. All items appeared to be fine, aside from teh small amount of housing / insulator broken off of the slot. I re-seated the chip, making sure to get a nice 'tick' as it snapped into place.

 

I was quite excited about this find. This could explain why the electrical gremlin appeared to be related to both heat and vibration, but not repeatable with either. The loose / poor / non-existant connection between the chip and the board could easily be lost due to revs. Also, the poor connection would be exacerbated as the items heated up and resistance increased. I was pleased by the find, but guarding my hopes. It just seemed too easy. I re-installed the 'problem' box in the yellow bike, and decided to go for a spin. A short spin, near the house, until I saw if any symptoms appeared.

 

The bike started fine, which was a good omen. It also (mostly) idled, dying only once or twice while I put my gear on. Leaving the house and headed down surface streets, the bike seemed to be running noticeably smoother than before. It was still backfiring no decelleration quite a bit, but I'm guessing that's due to a lean condition (full Staintune exhaust, chip setup for stock system w/ Mistral slip-ons). The bike seemed to be quite a bit smoother through the 3-4k band than it was yesterday, and it didn't buck or hiccup.

 

~120 miles later (in-town, freeway, up the Angeles Crest, etc), the bike was running great. I wanted to make sure I put some miles on the bike (previous issues had manifest themselves ~20 miles) as well as get some heat into the parts (ie, get some 'time' on the bike, too).

 

The bike still exhibits typical Sporti issues (rough idle, dies at times, not perfectly smooth from 3-4k), but it the electrical issue was gone during this 120 mile, ~2 hour ride.

 

I'm going to leave the red box (with UltiMap chip) in the yellow bike for now. This will 1) give me more time to test, and 2) a slip-on chip is bound to be better for a full system than a bone stock chip.

 

I'm thrilled. I'm thrilled the bike is running well, I'm thrilled I don't have to buy a new ECU, and I'm thrilled that it turned out to be an easy fix. So far, anyway. I'll still remain cautious, but I think this did it. Time to re-seal the lid on the computer, fix the final drive leak on the red bike, and get back to sorting the 'everyday' Guzzi issues.

[Guest ratchethack]

I commend you on your courage, tenacity, and self-sufficiency!!! This gives me encouragement, should I at some point develop similar symptoms, to go where I might otherwise have feared to tread. To me, anything inside the ECU case is haunted by mysterious binary spirits of dimensions measured in angstroms. Since I can't see stuff that small even with a microscope, I've always thought of everything in there as forbidden hunting ground...

[Guest bmonnig]

I commend you on your courage, tenacity, and self-sufficiency!!!   This gives me encouragement, should I at some point develop similar symptoms, to go where I might otherwise have feared to tread.  To me, anything inside the ECU case is haunted by mysterious binary spirits of dimensions measured in angstroms.  Since I can't see stuff that small even with a microscope, I've always thought of everything in there as forbidden hunting ground...

58295[/snapback]

*****

 

Well, I thought "If it's broke, can I make it -MORE- broke?" Heh. Glad I dug in there. I was able to blow out the ECU internals as well, as some dust / debris had worked it's way in (probably through the rubber boot) over time.

 

And, as a backup, I was / am watching some 16m computers on eBay. Besides, how can one own a Guzzi and NOT be willing to tear into stuff?