1st unofficial post from L3FTY, after storage, injectors leaking?

[FinalImpact]

[MENTION=29449]L3FTY[/MENTION]

Hello FinalImpact,

I’m writing because i'm chasing down an issue on an ’07 FZ6 and I very much respect your opinion and knowledge. I’ve been a lurker for a while and have followed your posts with great satisfaction. I've been turning wrenches on bikes for about 15 years now.

I have an ’07 that was purchased new for my sister in ’07 and cosmetically totaled in ’09. I refreshed the bike, and it was totaled AGAIN when my father was driving it back up to her in college. I refreshed the bike again and it sat for about 7 years. I recently pulled it out of storage, got it running (it started on the first try after the basic restoration procedures), and I converted it to a naked-spec. 9,500 easy miles.

The issue:
I note fuel pooling on top of the intake valves after shutting the bike off (approx. 0.5cc over each valve, all cylinders). This came to my attention when the bike required more revolutions to start that I remember. It acted like it was flooding. If started on the button alone it would crank for about 5 seconds and slowly chug up to idle where it would clear up. With the throttle butterflies cracked slightly open it would start instantly and immediately idle correctly. The bike has no issues off idle, but the oil smells slightly different than I remember. I might be grasping at straws with the oil smell, though.

Additionally, there was/is an intermittent misfire at idle when warm. Not sure if that miss is related. I’m also noting a slight temperature mismatch on the headers with my IR gun. Number 4 consistently comes in lower than the rest, however the gold coating on that pipe has been worn off as melted plastic was abrasively removed from that pipe, so I’m not sure if that is messing with the IR reading. The exhaust manifold clamps record temperatures closely between 1&4 and 2&3. I'll sync this weekend and see whats going on.

Here’s what ive done/verified:
3-4 tanks of fuel system cleaner at full-bottle concentration
TPS verified in spec with Diag. mode (miss related)
Plugs gapped and replaced (miss related)
Plug wires inspected and verified seated (miss related)
Electrical connections (including coils and ECU) disassembled and connectors greased properly (miss related)
Fuel pump screen cleaned and PR tested ~35psi.
No rust/debris in tank (shocking after 7 years. The vents were pinched so that might have helped avoid moisture ingress)
Injectors inspected, benched at 100% duty cycle, backflushed, swapped around, etc.

**I went as far as to purchase an entire FZ6R throttle body ($20 on ebay, the injectors share the same part #) and put it on the bike to test the fuel pooling issue. Ran, but still pooled after shut off. For future reference, the throttle bodies from the FZ6R are the same outside dimensions, but the I.D.’s are a slightly smaller diameter. Additionally, the pressure sensor is different but the TB retains the mounting locations for the normal FZ6 sensor, which mounts up fine. I noted that the TPS only read to 86% at full open, so there’s something there too. The air metering assembly was identical. Final note, the bell crank is circular and not a cam profile like the FZ6. I’m considering swapping the bell cranks and noting any differences in throttle response/comfort.

My questions:
Have you ever noticed a small quantity of fuel pooling on the intake valves after shut-down? Its not something i would expect people to look at all the time, but it doesent seem right to me. I know the batch-firing logic of the FZ is different and could conceivably cause latent fuel to vaporize then condense, but the fuel pools within 1 minute of shut down and it *appears* to be a material amount of fuel; I can saturate a large q-tip from each valve.

I have a difficult time comprehending that all 4 (8 if you count the FZ6r) injectors are leaking. Just in case you were wondering, it is in fact fuel and not coolant/oil. I checked with my nose, fingers, and a lighter on a q-tip sample.

I also have a difficult time comprehending an over-pressure situation in the fuel delivery as the PR is between the pumps check-valve and the fuel line.

I’ll be syncing the TB with my Carbtune pro this weekend in hopes of catching something not normal. Until then, do you have any thoughts on the issue?

Hi and welcome to the 4'uhm Mr L3fty.

I am sharing this here vs a PM as I think others will benefit from your methods and perhaps the outcome of this process.

That said I also find it unlikely 8 different injectors leak so we are on the same page. What I want to question is the details of your test method. How does one get to the intake valves to schwab fuel away?

At best, there is no quick access. Are you possibly referring to the Throttle Body (TB) Butterfly plates? Brass color and easily accessible with the upper air box lid removed?

Please elaborate how and where you are finding this fuel. Everything you wrote about it blubbering upon startup leans towards the excessive fuel being present thus you have my interest.

Regards,
F/I

 

[L3FTY]

Great question! Theres a couple of ways/stages: The easiest is to remove the airbox cover, hold the throttle open (with the bike off ), and shine a light down the velocity stack. If the rotating assembly stops with one of the cylinders in the middle of the intake stroke, you'll even catch a glimpse at the top of the piston (for what its worth). Further removing intake parts will yield a closer look at the stems and back sides of the intake valves. Pulling the entire throttle body will get you closest. I've done all 3 methods and verified that there is, in fact, fuel sitting on top of the closed intake valves. As another data point, running and then shutting down the engine with the airbox off will leave a nice cloud of vapor in the intact tract, which I presume is fuel vaporizing against the hot head/valve. Once this vapor clears, liquid fuel is visible. Enough to saturate a q-tip in around each valve.

Thank you very much for the thread! I'm looking forward to the Forum's insight and suggestions, and contributing what i can. I have to think this condition is abnormal. I'll snap some pics of the conidition and magnitude when i sync the TBs tomorrow.

EDIT: The visual method i used to verify the condition was the eerie greenish/yellow reflection that fuel leaves when look at with a powerful light. The physical method i used to take the sample was a long "Ramrodz" gun cleaning swab. Its basically a long q-tip on steroids designed to run through a .22cal barrel.

 

[FinalImpact]

That is concise. OK, the standing fuel cloud is not normal but if the cam timing is off could be an clue about another problem. Lets forgo looking close at the bike for a moment and do a quick test.

Take your spare injector set, either 1 at a time or all 4 on the rail and fill a hose with water (safe) or Fuel (not so safe), and position the hose so gravity feeds the injectors.

Position 4 cups below each injector.

Set your air compressor regulator to 35/40 PSI and connect it to the hose.

** MIND YOU - IF THESE INJECTORS LEAK BAD AND YOU USE FUEL** You just made a bomb! Do a dry run with water or paint thinner. Something less explosive!!!

If these injectors leak any noticeable amount in 5 minutes, they leak and you proved it. It is no longer chance it is fact.

Does that seem reasonable? Be safe!!

 

[L3FTY]

Thank you for the suggestion. I'll clean, dry, and then pressurize the spare TB over paper to look for evidence of leakage.

I'll be able to better tell if the cam timing is off when i hook up the vacuum gauges, but in my experience even 1* off will make itself very obvious, and this bike runs well across the powerband. The intake runners look clean and the vacuum pulses *feel* smooth across the cylinders when opening the throttle (subjective).

Something i was thinking about just now (thinking out loud here): If something is causing the ECU to overfuel to this degree, i dont think the cat could compensate. The exhaust doesent smell rich by any means but the fuel mileage on the bike is below what i expected (<120 miles to f-light). I don't have an o-scope to check injector pulse-width and but i've reset the ECU a couple of times now. Would an open in the O2 sensor circuit trigger a fault code?

Theres no smoke out of the exhaust when running, but i DID notice a white/gray puff on start up this morning, which i attribute to the quantity of fuel hanging out on top of the valves. Anywho, i'll report back on the TB leakdown test asap

 

[FinalImpact]

You should be in the 180 220mi range if all stock. My fuel controller at 13.0:1 AFR and 48t rear sprocket put mine in the 180 mi range IIRC.

The spray above the TB could also be intake valve leaning but obviously they wouldn't retain fuel if that were the case.

Please confirm there is no Fuel Controller on this!
PS - good job detailing everything. It makes this so much easier.

 

[L3FTY]

Thanks for the data; its very helpful! If i had enough posts to edit my signature it would be:

2007 FZ6 - 9,500mi - Stock - Naked conversion - Renthal Bars - Fender Eliminator

At some point the bike had a scorpio alarm and lojack on it. I think the lojack is still there but i remember removing the alarm 7 years ago. I'll go inspect the harness and make sure any of the scotch-lock "nicks" in the wires dont have any visible issues. I dont think either of those devices get between the ECU and the FI harness, but i could be wrong. Will inspect at next opportunity.

Additionally, if anyone is around the Dallas, Texas area and would allow me to borrow their fuel tank for 15 minutes to rule-out my pump assembly, i'll sync your throttle bodies

**Edit** in response to the vapor-in-intake, its more of a whispy smoke than a viscous cloud and its in all holes. Its not bellowing out of the throttle bodies by any means; its just hanging around in there when i open the butterflies and look. I can blow it out similar to a smoking gun barrel. My intuition tells me its a few drops of boiling fuel after the bike is shut off, and i want to say i've seen this before on various healthy engines. Either way, its a data point for this case and i'll stay cognizant of it. I'm going to try to come back with pictures of my next diagnostics.

 

[FinalImpact]

Free TB sync, just lend me your tank! haha!

Recap; the vapor mist is when off? Not at idle or when opened up?

You must have the OEM manual, yes? IDR it specifying injector leak rate or pump leak rate so that is a best guess that they should hold nearly leak free for 5min.

 

[L3FTY]

Affirmative; the fog is after shut down. I do not recall the service manual giving a leakdown rate for the FI system either. Just a go/no-go on fuel pressure.

I ran you test last night and did some more diagnostic detective work. I'll follow up in detail with photos but in summary, the FZ6R throttle body did not leak when charged wet to 30, 35, and 40psi, both static and with injectors energized (in case the pintles weren't re-seating). i'm going to call the fuel pump in for questioning and i'll explain shortly.

 

[L3FTY]

Here's the unit, after pulling out of storage and conversion to n-spec


This is down one of the v-stacks, approx 1 hour after a 30-min ride. I don't know if you can see the fuel, playing with the brightness on your monitor may help. Its a bluish-green. Its identical across all 3 closed holes.


Here's the gas in the tank when looked at with the same powerful LED light. The color is very similar to what is seen in the intakes, but clear to the naked eye.


Here's the offending liquid, sampled from the intake on a q-tip


And in case you were wondering if oil or coolant. I know it looks yellow, but i did some "exhaustive" burn testing of the samples and concluded it does NOT smell like the burning oil. It actually smells like bad gas (varnish), which gives creedence to the flash-off vapor theory.


Here's 5 seconds after shut down at operating temp. I wasnt about to light a match here just in case. Note that this is only present when the butterflies are opened.


And here's the leakdown test of the FZR6 throttle bodies that produced the same condition when installed. I duty-cycled these while pressurized to check the pintles and no visible leakage. At least not in the quantities observed around the valves. I use a bicycle pump because i have much better control over it. **EDIT** This gauge has since been tested and is innacurate. This gauge registers approximately 10psi below indicated. Actual pressure for this test would be approx 50psi


Here's my current thoughts
1) It would be a hell of a coincidence to have all 8 valve guides/seals go bad and leak at the same rate. When the liquid is removed, it doesent come back without running the engine again. I removed power from the fuel pump and cranked the engine a fair amount- No liquid pooling.
2) the condition is on all 4 holes and appears seconds after shut-down at operating temp

Summary: I want to test the fuel pump for 35psi. If there's an under-pressure situation, the fuel may not be atomizing and instead washing down the sides of the throttle bodes. When the engine is shut off, the injectors should slam shut, with the last atomized fuel charges getting drawn into the engine as the rpms go from 1,300 to 0.0. A sloppy spray pattern would paint the inside of the TBs and intake manifolds with liquid fuel, which could run down to the valves and get flashed-off when the violence that is intake turbulence comes to an end. The bike sat for 7 years and is almost 12 years old; we all know fuel pumps take a big hit from sitting. This theory passes Occam's razor, as injectors or valves would require assuming that all 4 cylinders are in a failure mode of equal magnitude. I'm still not ruling out a fuel control issue or synchronization issue, but those are a few tests away. As an aside, i cleaned every connector i could feasibly access in the wiring harness and found no disconcerting evidence .

 

[FinalImpact]

Ok good to know the R parts don't leak at 40PSI. Did they hold for 5min? And it sounds like you applied 12v. What did the pattern look like and what were you spraying?

You pointed out that you read several of my posts. The second most common failure mode is the pressure regulator getting debris in it and limiting pressure to the fuel rail. This usually results in hard starts and limited RPM under load but yours is fine.

As for the mist above the TB after shutdown, I suspect this is common but I have never personally looked for it.
That said and following up on what you stated, during idle we have batch injectors shooting fuel into spaces where it can't leave as the intake valve is closed. So during the shutdown process ignition and fuel are cut but we have atomized fuel between the throttle blades and the valves.

Although I have never looked, it stands to reason that the atomized fuel condenses back to a solid and runs down the intake runner to lay on the valve until it evaporates.

To me if this were excessive, when fired off say 20" after shutdown, it would rinse oil from the cylinder and piston and produce a blue puff upon startup.

My thought is this:
Thoroughly inspect your ignition system.
Run more fuel intake cleaner through it.
Connected a high quality, high accuracy pressure gauge to your fuel rail to monitor and confirm it maintains 36.5psi at idle and at least that to 5k or so. But honestly the pump is good for 75psi so I think **it should** maintain 36.5 all the way to 13.5k.... clearly I've never checked it.

But get a good gauge and carry a fire extinguisher if you ride with said gauge attached. A leak could ruin your life so be super smart with regards to risk vs reward as the risk is pretty damned high!

 

[FinalImpact]

PS I don't see this being an over pressure situation.

What I didn't dive into is this; what if you knew nothing of this vapor cloud or fuel sitting on the valves, what are we trying to address here? Would it just be the hard warm starts? That's why I hinted at looking close at the ignition system.

From a starting/driveability focus, what does it not do that it should and when does this happen?

EDIT: hindsight says the color difference from fresh fuel to valve TB q-tip is ah, normal. Every time the engine is turned off that atomized fuel dries out and turns brown. Add to this is the PCV oils being dumped into the intake. All that said it will be darker and frankly it seems pretty normal.

And thanks for NOT posting a q-tip sample from your ear or any other orifice for that matter. Although I'm sure I would have LMAO! Blah

 

[L3FTY]

The R throttle bodies held easily for 5 minutes. I cycled them with 9 volts, it was easier to solder up a 9v tester than to pull a 12v battery. I used isopropyl alcohol and then water for the spray test. I'll upload a video of the spray test tonight, pattern was reasonable.

This all started with hard COLD starts, which could be circumvented by cracking the throttle open slightly. I remember this hard-start being worse last month than this month. Hot starts have always seemed fine.
Theres a brief white/gray puff on cold start. There's a heavy concentration of seafoam in the fuel so the puff could attributable to that
Additionally, the engine sometimes develops a misfire at warm idle (never on throttle and i cant remember if it does on warm-up high-idle), I want to say this has happened when below 1/2 tank of fuel, but that could be causation vs correlation.
The oil was changed about 1k miles ago and smells a bit fouled, but i haven't worked on I-4 bikes for a couple of years so i cant remember.

The miss when warm does sound like it could be a coil issue; can you think of any tests i can run with my meter? I can check and trim plug wires and disassemble the boots, but I'd prefer not to throw coils at it without more evidence.

I'll check fuel pressures on Saturday, sync things up, and get a plug read; i'll report back with pics of findings.
I'm not sure if the fuel accumulation is even abnormal; hopefully someone looks down their intakes after a run and can verify that. I just thinks its a bit strange.

Thank you so much for your attention to my concerns. You've been incredibly helpful, and at the least someone googling this data may find the thread helpful in the future.

 

[FinalImpact]

New plugs although new, can be defective. I'd start with new plugs. Verify the killer/rocker switch is not oxidized as power comes through it. Many that use it to kill the engine vs using key find it fails.
Next is with the caps disassembled, affix sand paper or something abrasive to the end and clean the depth of cap and rinse with dielectric cleaner. I found that when measure the caps all parts measure OK until assembled. Then the ceramic resistor failed to make contact in the botton of the cap. Assembled you should get 10K ohm +/- a few.... after that make sure the cap threads firmly to the wire and doesn't free spin.

You can ohm the coils for reference but I wouldn't expect you to find something. Be sure to subtract lead resistance as it can fictitious ohms that the coil(s) don't actually have.

That's about it if the ECM connection has been cleaned and deemed good.

Good job and keep it up!
A rep point for being thorough!

 

[TownsendsFJR1300]

What would be the possibility of the ECM keeping the injectors energized AFTER turn off, then FUEL dripping INTO the intake until the fuel rail empties???

Perhaps running the engine, then turn off (air box off) and watch for fluid (fuel or ? ) drip/gather into that area.

It's getting there some how.

As much as what's in there(after power off), I'd think you could see it dribble in as it does...

 

[L3FTY]

Thanks for the tips and suggestions F/I and Townsends!

F/I:
I'll check continuity on the switches and coils, and rebuild the boots. The plugs are NGK CR9EIX's and were replaced after the miss was noticed on the original CR9E's. Gapped to Yamaha spec and installed appropriately. On the stock plugs i did not notice any corrosion/debris/staining on either the ceramic end nor the business end, and the burn pattern looked reasonable for 10% ethanol fuel (light tan with a hint of gray). The original plugs compared well with each other, however #4 was just a hair on the leaner side. That could easily be a sync issue which i'll check tonight. AFAIK the bike has never been synced since new. During the plug R&R the plug wires were handled gently and i checked for spinning caps and cracked insulators, but i'll take another pass a fine tooth comb. I'll also check for signs of arcing to ground around the high-voltage side of the system.

Townsends:
Thats an interesting hypothesis and i thought of that as well.
Based on the following premise:
1) injectors do not leak;
2) fuel is the liquid observed; and
3) the fuel pooling is not normal operation

Then we could infer:
1) the injectors are spraying too much fuel into the throttle body at the right time
2) the injectors are spraying amounts of fuel into the throttle body at the wrong time (including off); or
3) The injectors are not spraying the fuel properly into the throttle body.

I'll do a voltage check on the injector harness tonight. I'm guessing any volts is bad volts with the key off

Last night i was installing some go-fast parts on another project bike when a thought crossed my mind- On diesel trucks (my other hobby), a poor man's turbo upgrade is achieved by disconnecting the MAP sensor. This tricks the PCM into thinking the intake manifold is at full boost, and fuels accordingly. Theres a ton of black smoke, but the turbo lights off faster. Just gotta ignore the check engine light and the toasty EGT's All this to say, i'm going to check my MAP sensor tonight. The FZ6 wiring diagram shows the reference signal to the ecm to be Pink/White which i'll check. The only bust to the fueling theory is that the bike runs well, does not smoke, and the exhaust doesent smell rich.

Thanks for working through this bike with me fellas. Expect feedback regarding:

1) switch continuity
2) Plug wires & coils
3) Fueling voltage
4) Fuel pressure. Static, KOER, and leakdown.
5) TB sync.

 

[FinalImpact]

If the ignition and injection were hot the bike would keep running so, not it.

Honestly if 5 of us warm them up and look, I think this is pretty common on any ICE engine.
Recap: we have port full of atomized fuel/air, you trap it under heat and walla, it condenses back to a solid. Then we have the open intake valve(s) that may or may not have fully exhausted the last combustion cycle and that crap goes back up the intake adding to the dark film in the intake.

Anywho there are plenty of these that don't start at the drop of hat. Mine has never been one and it has had some fueling and ignition changes, none of which impacted its start up.

Many engines that never see RPM build up carbon on the backside of the intake so I am 99% certain what you are seeing is the norm and your hard start issue is something else.

Verify fuel pressure...

 

[L3FTY]

F/I i'm on board with your synopsis. Combine physics, thermodynamics, and a batch-fired fuel injection system and i would have a hard time explaining why fuel WOULDNT be present in the intake after shut-down. Hopefully some others verify this in time. Quick question, could you describe a healthy idle on these bikes to me? This one has a slight flutter to it, almost like a soft intermittent popping. Not enough to move the tach, just a very soft and subtle fluctuation that i would presume untrained ears would not notice. Is your idle rock solid?

I did some more diagnostic work last night:

Checking fuel pressure
TB sync
Checking plugs & wires

We'll start with the fuel pressure results; i'm over spec with 41 psi running. Apparently when i checked the FPR with my bicycle pump, the gauge on that pump was off by ~10psi . I checked that gauge by inflating my tire to a known pressure with an expensive tire gauge (that i trust) and reading the tire pressure with the pump's gauge and then the fuel pressure gauge. The fuel pressure gauge was on the money, the pump was 10psi short. I noted that with the bike shut off the line held pressure at 30psi for 5 minutes when i ended the test. I actually ended the test by unplugging the fuel pumps power supply and starting the bike. The bike idled for about 20 seconds on static line pressure until the line went dry. I looked down the stacks after that; no fuel present. I dont know if this is a finding or more of a "duh". I'll have to think about what i can infer from this observation.

With that being said, do you know a way i can physically manipulate the FPR? When i benched it i tried pressing the center rivet from the pump side of the regulator and couldnt get it to budge. I could get air past it, but apparently at ~40 psi. My next hope is to soak it in penetrating oil and give it some short blasts with high pressure. Perhaps even cold motor oil or grease to get some hydraulic action working on it. Do you think 40 PSI is something to worry about?



Next was syncing the TB's. Untouched, the TBs showed ~10mmHg variance. I tightened the spread to around 2mmHg using the #1's vacuum as the baseline. #1 registered on the Carbtune at ~19 cmHg, and the book calls for 21.8cmHg. I *could* have adjusted it up to that, but i dont even know if the Carbtune's gauge is accurate in that respect. I was more concerned with balance than magnitude. Thoughts? Pic is after synchronizing.



Finally was the plug check. On all 4 plugs i noticed a black sludge around the ends of the threads. It did not wipe off easily and smelled a bit like oil. I'm not sure if this is a product of top-end cleaner soaking and a lot of idling, but i have trouble thinking all 4 sets of piston rings and/or the head cracked in 4 spots all at once. I'm not seeing any oil consumption, soot around the exhaust outlet, or smelling any burned oil (in case you havent noticed, my olfactory bulb is one of my more commonly used diagnostic tools ). These plugs have <1 tank on them (with a ton of seafoam in it), about 60 miles of actual riding, and lots of idling and no-load RPMs. All the plugs shared the same pattern, however the #4 electrode had some white solid build-up around the shaft. I have no idea what that is, it almost looks like a chemical reaction of the iridium. I dont have a leakdown tester but perhaps its time for me to buy one.

Plug wires passed my inspection but i'm considering taking the coils completely out and benching them.

Since the bike starts reasonably reliably, and runs through the powerband well, i'm considering giving it a hell of an Italian tune-up. I have access to a nearby motorcycle dyno so i might give it the a hot supper and check the AFR with it. Thanks again for all of your help to this point! Will be a fun activity at the least.

 

[TownsendsFJR1300]

A normal idle but with open Scorps, cold start (video'ed to show charging voltages).

I do keep the warm idle at about 1100 RPM's:

https://www.flickr.com/photos/147134237@N06/29303851750/

My last sync after a valve adjustment about a month ago(26,600 miles):

 

[FinalImpact]

Man is there anything anywhere you could verify that gauge with one more source?
42psi is what the R6 runs with a return system and people who dropped this unit in confirmed start and idle issues!!!

WOW - if that is the case, is there any any any crazy chance that PR got swapped? It seems unlikely given the history and I hate to say BUY an FZ6 pump just to get a PR.

** Do not soak PR in OIL** it may degrade and swell it. I would however find a method to verify your gauge.

Beyond that it wouldn't surprise me that all the toxins being released by the cleaners would lead to deposits on the plugs. Flogging may or may not change that.


Bottom line is if the FP is 41PSI it may be a huge factor in startup.

That said a few PSI over is a small percentage given the injector duty cycle at cranking speed. HOWEVER - this is a small engine and we have seen under pressure cause no start. In short this fits your symptoms of cracking the throttle to start.

Please verify that gauge with something calibrated.

Abstract but look up certified Electronic Calibration places in your area. You don't need a cert just a warm fuzzy that your gauge is 36.5psi +/-1% or roughly +/-0.4psi at that value. Maybe they'll test for free.

Last option would be loaner gauge from local auto parts store.

Gotta go. Check back later.

 

[L3FTY]

Good idea and thanks for the info about the R6 pumps and peoples experiences. I tested my fuel pressure gauge with a tire inflated to 35 psi. The tire was checked with a Snap-on tire gauge. I'll see if i can source another fuel pressure gauge and run the test again. Still hoping to find someone with an FZ6 that will let me borrow their tank assembly; would make this so much faster and rule out 30% of the system. I might have to chase someone down and wave some cash around next time i'm out riding. I've got a crossplane R1 that might keep up

This is the PR that is in the pump. AFAIK its been there since the factory put it there. I'll ask my dad and sister if they know anything about this pump that i dont. I would feel quite betrayed if they had work done on this bike without consulting me first Also, i dont know if these part numbers are worth anything.