New guy, need help troubleshooting no start.

[Fishtank]

Hi all,

Been lurking on here for years, this Summer presented me with the opportunity to finally purchase my dream bike. 2008 XB12ss in Valencia Orange, one previous owner since new left it absolutely bone stock, just over 10,000 miles on the clock now. I purchased the bike this and rode it home, 1350 miles over 2 days. Spent a few weeks riding to and from work then another long 375 mile trip to meet with my wife. Just as I was within a mile or two of meeting her, the bike started to run horrible, stuttering bad at low revs and idling rough. Loaded the bike and drove back home. Now it won't start at all. I know how important details are so I will list what I can think of below.

2008 XB12ss
K&N filter
Stock muffler
Grounding mods completed nose to tail
Replaced plugs with NGK Iridium 400 miles ago
Replaced plug wires with new suspecting bad wire
No code being indicated by check engine light
Fuel pump primes during pre-start
During attempts to start I've had a couple after-fires out the exhaust and a single back-fire out the intake (Yes Lunatic, I've been paying attention)
Mostly it just cranks with little signs of firing

I am going to double check for trouble codes using the jumper/test wire and would appreciate any suggestions for what else to check.

Depending on what you guys suggest my next suspects are as follows:

Check coil for proper resistance
Check cam position sensor for movement or any wiring problems

Really hoping to get this running again since my riding window for this year is closing fast.

Thanks in advance for any advice.

Ted

 

[user_deleted]

ted: well done on your nomenclature regarding flying fire-balls during cold start procedure. i salute you Sire!
1-see link below for simple fault code retrieval.
2-the flying fire-balls is always 100% ignition related. can be fouled plugs....coil plug wire from main harness shorted to ground....loss of ECM ground.
3-to confirm #2 simply remove front spark plug as it's the easiest to access. blackened and fuel soaked? loss of spark!
4-humor me if you haven't done this check already: remove fuse box lid and check IGNITION FUSE. remove.....check it....clean terminals it plugs into....reinstall. and while you're in there carefully check KEY SWITCH relay. how??? key off...kill switch to ON...fuse box lid removed...now turn key to on while listening closely to fuse box area and placing a finger on the KEY SWITCH relay. you should hear it "click" AND feel it "click". it's subtle but you can tell.
BEFORE YOU DO ANYTHING ELSE check that plug AND examine the bike to confirm that you have a clutch lever safety interlock switch AND a side-stand safety interlock switch. most do....some don't. they are simple Nissin "button-style" circuit interrupter type switches. rule them out as the culprit. how???? simply remove the 2 wires from each....place pins of multi-meter on terminals and set meter to OHMS....and work the switch. if healthy should see meter go from infinite ohms to 0 ohmrs.
the above is where i'd start.

https://www.buellxb.com/forum/showthread.php?26630-Trouble-Codes-08

 

[Fishtank]

Thanks Lunatic, I forgot to mention that I already checked ECM connectors, battery terminals and fuse conditions. I will actually pull the ignition fuse, clean and check connections but the box was clean and dry, I will also check the relay while I'm in there. Then my plugs and report back.

As for the switches, definitely no side stand switch. Would the clutch switch be on the lever?

 

[Cooter]

Ya the clutch switch is 2 wires on the lever, but that would affect cranking, not ignition.

The clues of 'running well and just started to run poorly, then no start' I would guess its the CPS. Fairly inexpensive part and easy to swap, so worth a shot-in-the-dark guess.

Next guess would be fuel pressure or chaffed wires at the pump inside the tank. Also easy to check:
Hang the rear of the bike, remove lower shock bolt, hang swingarm, drain tank, remove pump. Might as well put in a new fuel filter while its out.

Have you tried opening the throttle while cranking? It will add air. Extended cranking will foul the plugs for sure. The DDFI-3 ECM's like your bike has, have a plug cleaning procedure (in the manual) as well (Lunatic taught me that:angel

 

[Fishtank]

Hey Cooter, I did try various throttle inputs while cranking, no noticeable change there. If I have to dig as deep as removing the fuel pump I will definitely be replacing the filter while I’m there. I’ll look for the plug cleaning procedure, any hints to what chapter and verse these wise words would be located?

Is there a way to confirm correct fuel pressure and regulator operation without the fancy connectors I see in the service manual?

 

[Cooter]

I don't know the location, it's easy though. Try searching on here. Maybe Lunatic will chime in with the procedure again?

Sorry, fancy connectors needed. Fuel pump removal is easy. I can have one out in 10 mins and I'm dumb with large hands and 10 thumbs

 

[34nineteen]

Squirt a shot of starting fluid down the throat of the beast (with the throttle open) and try to start it. If it likes that, you likely have a fuel issue. If not, its likely ignition.


It think lowkey and (the one who shall not be mentioned) struggled with finding the correct fittings to read fuel pressure.

 

[Fishtank]

Okay, update time.

- Checked fault codes, none showing.
- Checked Ignition fuse and key switch relay, clean & dry with good contacts.
- Replaced plug wires with new factory.
- Checked front plug, it was blackened and wet looking so I checked spark, good spark on both front and rear plugs.
- Checked wiring best I could in the short time I've had, but Ill have another look with more time and better lighting.
- Fuel pump is working as advertised.

So I am getting spark and air, the only thing left I can think of is a blocked injector, fuel filter or fuel pressure regulator. I'm hesitant to try a squirt of starting fluid down the throat, just seems like asking for trouble.

Alternatively, is it possible to have a bad crankshaft position sensor sending timing off without getting a trouble code?

 

[Chicknstripn]

www.buellmods.com for a service manual.
Since your bike is an 08 I would suspect an issue with your idle air control valve(IAC).
Google cleaning procedures for IAC
Also, I would start with fresh( properly gapped) plugs and refrain from twisting the throttle while trying to start the bike. Buell’s foil plugs very easily if throttle is twisted/blipped on start up or on a cold engine.

Can you recall anything out of the ordinary prior to the bike crapping out on you? Seems odd the bike ran so well for so many miles then gave up.

Your battery, and all connections related to said battery are good?

Good job trouble shooting so far.
Don’t lose faith, you’ll figure out this issue soon...

 

[Silverrider]

When you bought the bike has it been sitting for a while ?? As 3419 said spray a little gas in the TB and see if it wants to run , It could be clogged tea bag on you pump filter as it was on a 08 I had. ( could I use the word Tea bag ?)

As Cooter said fuel pump is my guess. Spray gas test will answer that !

 

[Fishtank]

Thanks guys.

Lunatic, new NGK iridium plugs were properly gapped and installed less that 400 miles ago, shouldn't be the problem.

Carlos, I will clean the IAC this weekend and do a gas spray to double check and go from there. I may just pull the whole throttle body to do an ultrasonic clean on the injectors while I'm in there too. I completed a nose to tail re-grounding as per instructions on the site and have a full battery with good cranking.
There was a little hesitation during my long ride at lower RPMs and light load but otherwise it ran fine, not as smooth as others I've seen but well enough.

I'll pull the fuel pump if I have to but that would probably be the end of my riding season, my wife has raised a few eyebrows at my decision to get a bike that "needs work". She wants to go on a few more rides with me before the snow falls.

Silver, with a picture like that use Tea bag all you like, it's more accurate and concise than dirty homeless shelter pillow.

 

[Silverrider]

When you bought the bike has it been sitting for a while ?? With fuel in tank ?

 

[Fishtank]

Not 100% sure, it is a possibility. I'll contact the seller and ask.

 

[Chicknstripn]

Ok
If the injector cleaning doesn’t work I’d go with pulling the fuel pump. Changing out the fuel sock and filter is a good preventative measure on a ten year old bike.

Wife raising an eye brow?

This is what I tell my wife, “would you rather I spend time in the garage with my bike, or out at the bar with the fellas boozing?”

Pull the pump first thing in the morning and you’ll be riding to your favorite lunch spot!

 

[Silverrider]

I forgot to welcome you to the board, Lots of knowledge in this group especially John ^^^^^^^above, I would like to see a pic of that 08 .

 

[Fishtank]

Okay, update time.

Tried the ol' gas down the throat, hit the starter, it fired up and held idle until it ran out of fuel. SWEET it's a fuel issue.

Already had the fuel filter and screen on order and finally got time to pull the pump, this is what I found.


I pulled the e-clip and the screen fell apart once I slid the pump assembly off the base. The inline filter seals were dried and cracked once I tried to slide them off the old filter.

I used fuel rated hose to replace the cracked seals and installed the filter screen on the pump intake. Unfortunately the cross-referenced screen I received didn't fit the base very well, I had to lift and slightly rotate the pump to get the screen to fit.


Reassembled everything and it fired up faster than ever before and ran quite smooth during a test ride. HAPPY DAY.

Next day, my wife and I went for a couple rides to town and the bike ran very well, until it got a bit warm... similar poor idle with sputtering and afterfire mixed with what I felt was a very occasional backfire, I could hear it under my chin in the intake. I have new plugs to replace the ones with only 400 miles and also picked up a new Bosch O2 sensor, figured I'd change them out separately and see what changes.

Snow starts tomorrow, so my window is closing until storage.

 

[Fishtank]

Silver, a few pics for you.

My ride to work.


My ride at work.


Its surprising how the sunlight reveals all the blemishes, next on the list is a muffler upgrade in the spring.

Couldn't get the last one upright.

 

[Silverrider]

Glad you have the fuel issue fixed. Nice looking bike !!!!!!

 

[Cooter]

Nice rides!

You'll find a service manual and diagnostic flow chart at Buellmods.com or Buelltooth.com

If you want a better diagnostic tool that swapping parts randomly:black_eyed:, I'd suggest ECMDroid. It's free on the google play store. You'll need to connect to the bike with a bluetooth dongle, I like the one I got from Buelltooth.com

Oh, and I like my stuff shiny. There are much better pro's on this site, but this works well for me!
https://www.buellxb.com/forum/showthread.php?51500-Buell-plastic-scratch-removal