sooty rear cylinder

[steampunk]

Oh yeah, I'm sitting here wondering: if the fuel pump doesn't cycle on and off by pressure what does control it?

The above photo is as I got the bike.  I have to admit that when I saw it on ebay it stood out from all the other bikes i'd been browsing for months . . .

[wytfut]

Wytfut is the phonic spelling of my real last name... Whitefoot.

No I'm not..... Not that there is anything Wron with that...... Just for you Mike Locklear!!

OK Mr. Mike here I've always thought the pump was self regulating...... What does govern the pump to come on and off

[2CoolWheels]

The pump gets a signal for 2-3 seconds from the ECU on initial key on. Then, when the engine is running, the ECU keeps it energized. Pressure is regulated in the tank by the regulator which bleeds off excessive pressure while the pump is running. So any cycling on and off by the pump is done by the ECU and is not based upon actual fuel pressure. Pressure is mechanically regulated by the regulator whether the pump is running or not.
And if I am wrong, Jamie will send bad voodoo my way!

[steampunk]

Coils passed primary and secondary resistance tests, also spark on the bench from the battery.

Fuel injectors w/in electrical spec and cleaned. No leak at bench test (spray can pressure).

ECM tune is 8352.

The only thing I have found wrong on the "sooty cylinder" is the bad boot and the fouled plug to coil connection.

[wytfut]

Thanx Mike!!

Steam... I'm at a loss at this point
Wet and sooty
Injectors test good..
Appears to be running good..
Coils test good..
Compression good

Change plugs again would be my next step. Had an issue with brand new plugs 2 years ago. 5 out of 8 brand new plugs were bad.
Have you done any sort of vacuum leak?

[blackheart]

If it's not missing out under heavy loads then this more or less states the coil & plug would not be causing misfire at lighter loads.

Since it's the rear cylinder which has the o2 sensor use a high impedance VOM which will read out the average DC mV when engine is hot and you are above idle say at 1500 rpm.  It should be in closed loop and thus it will be rapidly fluctuating from far less than 0.45v to far more.  450 mV is stiochiometric  combustion and is where most ecm's would be trimming fuel to.  It might be they have it set to something slightly higher to run cooler such as 500 or even 600 mV.  But still you should see it fluctuate rapidly which means it's in closed loop.  Unless it's above 600 mV continuous I'd say your soot may be oil consumption, especially if it's shiny on the base of the plug.

If it were the front cylinder we could expect to find a vacuum leak on the rear possibly and the ecm would be dumping in extra fuel to compensate for the leak on the rear while the front with no leak is overly rich.

[wytfut]

Thanx Rick!!

Hope all is good in St. Jo!!

[steampunk]

Thanks both wytfut and blackheart, but I don't understand why neither of you like my fouled boot theory: 

With a fouled, but not completely insulated, coil to plug connection at low rpm and cold the firing pulse from the coil would have a harder time getting the coil discharge across the fouled connection to the plug.  With only the front cylinder firing regularly the engine would certainly heave fore and aft as mine did.  As rpm increases the bike would be producing a stronger current which would more easily cross the fouled connection.  Also as the bike warms the fouled coil to plug connection would probably provide less resistance (like insulation breaking down under heat inside a coil) and the bike would again run better as mine would finally get down to normal idle rpm after 20 miles.

I guess I'll find out in spring when I hopefully ride the roads with it.  Although it is 50+ degrees and a thunderstorm that woke me out of bed here in Deeetroit this morning.

I have to go to a dictionary and textbook to follow some of Blackheart's terminology!

[wytfut]

To be honest steam...
I thought it was a given, that you'd replace..

Bruce

[steampunk]

I'm too poor to throw money at the bike--at least until I can make a full assessment of what I have.  I don't want to buy coils or injectors and then find some other crucial and expensive problems.  It was running down the road with freeway traffic or stop lights last year, just the engine heaving at idle and poor gas milage, then the black and wet plug which air dried itself overnight.  The ride sure beat hell out of my sportster which is great for quick errands around town.

You have certainly helped me figure out what is defective or not with everything coming back with a passing grade so far.

Today, after breaking my 3/8 T45 and buying a new 3/8 and 1/2 T45 and soaking the bolts, I hope to get the rear wheel off and check/grease the bearings,etc.  I haven't figured yet how much wheel disassembly I'll have to do to inspect the bearings (this one, i'm told, has been sleeved long ago with a double bearing on the drive side).  I guess taking off the drive pulley would have me on the proper side.  Anything I should watch for in particular?

But one step at a time, caliper bolts first.  The front caliper had hex head bolts while the back has torx: Were the front caliper bolts replaced?  Is that a good idea or only if needed?  I can get hardened bolts . . .

[2CoolWheels]

Steampunk,
   For quite a while, I had an engine miss while riding 901. I could never get it to do it when the bike was stationary, so I could never determine which cylinder it was. Both plugs looked good, but I changed them anyway. Still every once in a while, I got a misfire. Sometimes it would be really bad and the bike would loose power and shake a lot. Other times it was very slight, and barely noticeable.
   Finally, after about a year of this very intermittent problem pissing me off, the front cylinder quit altogether.....bad coil. Once I replaced the coil, the bike has run perfect since.
   So I guess what I am saying is, ride the bike and enjoy it. If everything checks out good, other symptoms may crop up later to give you guidance to the problem.

Mike
901 741

[steampunk]

Hi 2CoolWheels,

My F150 was doing much like you describe, missing under load, intermittent misses, etc just as you describe your bike did.  All told me coil, I did a spark test in the ignition wires, no problem.  Got worse so went to the shop: COIL.

But the symptoms I'm describing for this X are different: It runs fine at speed or under load, no misses discernable.  It idles well when fully warmed up (like 20 miles).  it is at low rpm and cold the engine heaved two and fro, the idle fast (1100 rpm). 

If all else on the bike checks out maybe I'll come back to them if it nags me.

Took the rear wheel off today (red locktite on the caliper bolts)  Bearings feel good with pulley and rotor on.  Not sure whether I should remove them to inspect the wheel hub to sleeve. Double bearing on pulley side.  The bearings are a little tighter to turn than I expected but then my experience is with tapered p/u or car wheels.  I don't find any play.

[wytfut]

Steam..
Not sure why it takes 20 miles to fully warm up.....
Ambient temps 70+ here, mine is warmed up within quarter mile...

Heaving at idle reminds me of stuck jet... Not the case here, Lets try cleaning the AIC tube out... And the plunger, maybe it's hanging up.. does the vacuum port on top of the body have a good plug. Symptoms there probably wouldn't be like yours, but OEM rubber plug does fall apart.

Brake calipers are torx front and rear. OEM is orange lok tiite (permanent), a real bitch to work with. Sometimes a lot of heat with a soldering gun, or a jewelers torch helps.

If bearings spin smooth.... Only other thing to look at, does the bearing just fall out?...   Lololol, had that issue last fall.

Lastly... As rediculous as it may seem, run a little sea foam thru it acouple tank fulls. I still don't trust those injectors. I've solved a couple of X issues just doing that.

My cold idle start is around 1500, and OEM warm idle is supposed to be as close to 950 as possible.

Out mention your tune?.. did you X come with the CD and cable?...  Your symptoms should show

[steampunk]

Hey Wytfut,

By the "AIC" are you referring to the Idle Air Control?  If so, I did get John's Repair air cleaner loose but haven't taken out the throttle body yet.  I'll be looking into it, thanks.  But as you know, a problem there would probably show in both cylinders.

There has been some messing around with the ECM area.  Tilt switch is gone and the connector jumped.  I'll have to look into the 'vacuum plug'.  The bike has 8352 in felt tip, I think there is an 8352B?  I'll search that here too. (Also George Soine is felt tipped on the side)

I've heard good and bad about seafoam.  That I can do when up and running if my problem persists. I'll look into take lining issues as well.

Before putting the bike inside 70 was probably about ambient average, a little less.  2200 rpm start, 1100 first 20 miles, then 900.  That is part of what makes me think the fouled coil/plug connection could have been the problem: When hot that connection would more easily transmit current and I would think it would take a while for the engine heat to travel to the top of the plug and boot.

Fortunately, my bearings didn't fall out. .  Since it came with nearly new tires I knew the wheel had been off recently but that didn't mean the bearings where greased.  They look and feel good.  I'm going to polish up the wheel and check the spokes, both a bit rough. 

No examinator, cable, or CD.  I have downloaded manuals but the service portion is missing a lot of diagrams/illustrations.  I go back and forth between parts manual and service manual. 

[wytfut]

Craig....
A lot of the tilt switches have gotten rusted thru the years and prevented starts.... so there are a growing number of them that are getting jumpers...   
I know of no 8352B..... that doesn't mean there isn't... it means I haven't heard of it.
I do have a later tune than 8352, built by another X owner.... that I really do like... But I'd guess there maybe a few other tunes out there by some of our more rambunctious owners....
2200rpm cold start is way too hi.... I'm now guessing your computer is trying to compensate for that missing spark....
The factory manual is missing large pieces....   although I heard someone did finish it later... but don't remember who...