Fuel Pressure Question

[Oakdave]

I have a 2007 FJR1300. I'm trying to troubleshoot a problem involving an engine warning light, with error code 32 (and no, I do not have a PCIII or any other aftermarket stuff on anything engine related). The fuel pressure--a reading of which the maintenance manual calls for (based on the error 32)--is reading between 48 and 49 p.s.i. The maintenance manual says to replace the fuel pump if the reading is not 47.0 p.s.i.. Anyone here on the forum familiar enough with fuel pressure to know whether or not 48 or 49 p.s.i. (versus 47.0) is actually cause to replace the fuel pump? (The difference-- 48/49 versus 47.0-- just doesn't seem to be very much...but I don't know anything about fuel pressures and if there's any room for tolerance). Anyone?

 

[Ignacio]

Does it say it has to be specifically 47.0 PSI or a minimum of 47.0 PSI? I'm going to bet its a minimum thing....which makes 48,x, 49.x, or even 47.1 just fine.

 

[FJRay]

Not sure but I would bet that there is that much variation from one tester to the next.

 

[Oakdave]

Does it say it has to be specifically 47.0 PSI or a minimum of 47.0 PSI? I'm going to bet its a minimum thing....which makes 48,x, 49.x, or even 47.1 just fine.

To be clear, the maintenance manual does not state that the 47.0 is the minimum pressure (to check for). In fact, in the troubleshooting section pertaining to the error code 32, the manual states that one problem that could be the cause of the error is if there is TOO MUCH FUEL PRESSURE, so it says to check the fuel pressure.

The following text is copied directly from the maintenance manual, in the section pertaining to how to check the fuel pressure (steps a - d are omitted because those steps just pertain to how to go about connecting the fuel pressure gauge between the fuel tank output line and the rail):

e. Start the engine.
f. Measure the fuel pressure.




Output pressure (result should be)
324.0 kPa (47.0 psi) (3.24 kgf/cm²)

Faulty → Replace the fuel pump.

That's it. It just specifies 47.0 psi, period. (And to replace the fuel pump if the output is not 47.0 psi).

 

[dcarver]

I doubt 2 psi higher would make any difference. Just a guess though.

Good read here

https://boosterplug.com/images/shopdownloadfiles/BoosterPlug%20Fuel%20Injection%20Book.pdf

and Yamaha videos

 

[escapefjrtist]

How confident are you that the test equipment will read within 1 psi? I can not see how that slight observed variation would cause problems.

~G

 

[Ignacio]

How confident are you that the test equipment will read within 1 psi? I can not see how that slight observed variation would cause problems.
~G

Well, more accurately....0.1 PSI! If that's what the manual says "47.0" and doesn't specify tolerance then 46.9 is too low and 47.1 is too high.

But, I'd not sweat a couple psi personally...

 

[RossKean]

I very much doubt that a couple psi would have any bearing on the error. I would be surprised if a gauge was accurate within that interval in the first place. Fuel viscosity as a function of temperature or formulation would likely have more of an effect on delivery than a 5% difference in fuel pressure. The manual suggests a few things but I think I would check out the O2 sensor (and connections) first. I once had a rich running condition when I pinched the O2 wire in the timing cover after some maintenance stuff. Don't remember any error codes but it ran stinking rich!

Is the bike running OK? Is fuel consumption excessive? Does it smell like it is running rich? Does the error come and go? If so, under what conditions? Try a dose of fuel system cleaner?

I had the Error 32 on my '07 shortly after I bought it (used). In my case, it was related to a Power Commander which I ended out taking off the bike for other reasons. (I know that isn't your situation as you clearly stated there are no aftermarket devices on your engine.)

 

[Oakdave]

I doubt 2 psi higher would make any difference. Just a guess though.
Good read here

https://boosterplug.com/images/shopdownloadfiles/BoosterPlug%20Fuel%20Injection%20Book.pdf

and Yamaha videos

Thank you very much for these resources! I will read the book and watch the videos...and hopefully that will shed some light on this subject for me.

 

[Oakdave]

How confident are you that the test equipment will read within 1 psi? I can not see how that slight observed variation would cause problems.
~G

Well, more accurately....0.1 PSI! If that's what the manual says "47.0" and doesn't specify tolerance then 46.9 is too low and 47.1 is too high.

But, I'd not sweat a couple psi personally...

You're correct, Ignacio. The manual makes no sense, really...considering exactly what you are pointing out. With its '47.0' requirement, one would need a fuel pressure gauge capable of reading exactly down to within +- 0.05 psi (which mine doesn't)...and, even then, there could be no fluctuation occurring (nor realistic). This is what is frustrating me-- that the manual does not specify any sort of tolerance (high/low)...yet warns that if the pressure is too high, that that could cause the error 32 I'm getting.

 

[Oakdave]

I very much doubt that a couple psi would have any bearing on the error. I would be surprised if a gauge was accurate within that interval in the first place. Fuel viscosity as a function of temperature or formulation would likely have more of an effect on delivery than a 5% difference in fuel pressure. The manual suggests a few things but I think I would check out the O2 sensor (and connections) first. I once had a rich running condition when I pinched the O2 wire in the timing cover after some maintenance stuff. Don't remember any error codes but it ran stinking rich!Is the bike running OK? Is fuel consumption excessive? Does it smell like it is running rich? Does the error come and go? If so, under what conditions? Try a dose of fuel system cleaner?

I had the Error 32 on my '07 shortly after I bought it (used). In my case, it was related to a Power Commander which I ended out taking off the bike for other reasons. (I know that isn't your situation as you clearly stated there are no aftermarket devices on your engine.)

Ok...thank you...I will check the connections/wiring related to the O2 sensor (and be sure there are not issues there).

To answer your questions:

- At this point, the bike will start but it runs so rich that it wont keep running unless I keep the throttle opened manually.

- Until about a month ago, the bike was running just fine until, all of sudden, it starting showing signs of trouble a idle. Bike ran great (normal) at speed...but idle and very low speed (under 5 mph) became the main issue. Bucking,hesitation...until it eventually got to where I had to keep the throttle open manually all the time when stopped (idle) and when coming to a stop (which is not all that easy on the AE model). At one point, the engine warning light came on...but no error code. The light eventually went out (after about 10 minutes of riding). Light did not come back on. Continued riding the bike for another week after that, but the engine idle and slow speed riding got worse and worse...to where about 2 weeks ago I decided to stop using it as my regular daily commuter...and start trying to seriously troubleshoot it.

- I ran a compression check on the engine, and that seems to be 'good enough' in all 4 cylinders (ranging from 132 to 136 psi across all 4). Valve check performed last week by me...and all clearances were within spec. New spark plugs. Replaced the O2 sensor with a used one from a low-mileage one on eBay.

- After replacing the o2 sensor and the plugs, I decided to test ride it...and this time the engine warning light came on...with an error '32' code showing in the dash/display after turning the bike off and attempting to restart it (which it WILL do-- the bike does still start up). Using the built-in diagnostic system, I've checked the throttle position sensor, coil signals, fuel injector signal to each of the four injectors, coolant temp sensor, air temp sensor, and intake air pressure sensor. All seem to be okay.

One thing that is troubling is that when I disconnect the cam position sensor wire, an error code that I would expect to see appear in the dash/display when in the diagnostic mode)-"an open or short in the cam position sensor"--no such error code is coming up (just the '32' error code). Same thing if I disconnect the O2 sensor from the harness-- no code indicating "no normal signal is coming from the O2 sensor" (even though such an error code exists). But, if I disconnect the connection to the coolant temperature sensor then the (expected) error code DOES appears in the dash/display (intermittently displays along with the '32'). Because of this, I am beginning to become suspicious that the ECU itself may be bad.

A final thing I should point out is that my bike has 196,000 miles on it. It is the AE model.

 

[RossKean]

Definitely unplug and reseat the ECU connector. Check that the pins are not bent or corroded.

Have a look at this

https://www.fjrforum.com/forum//index.php/topic/170314-fault-code-14-gen-ii-solved/

Similar symptoms but a different code. I assume you are not getting a Code 14 as well??

Easy to check out with the tank lifted.

 

[Gitbox]

if I disconnect the O2 sensor from the harness-- no code indicating "no normal signal is coming from the O2 sensor" (even though such an error code exists)

I discovered the same thing when I unplugged the O2 sensor per Power Commander recommendations. I guess the ECU doesn't really care.

 

[RossKean]

if I disconnect the O2 sensor from the harness-- no code indicating "no normal signal is coming from the O2 sensor" (even though such an error code exists)

I discovered the same thing when I unplugged the O2 sensor per Power Commander recommendations. I guess the ECU doesn't really care.

It doesn't seem to care if there is NO O2 sensor but behaves badly if there is an O2 sensor that is providing incorrect information - as per my situation when I had a pinched O2 sensor wire. Might be worth seeing how it runs with the sensor disconnected.

 

[Oakdave]

Definitely unplug and reseat the ECU connector. Check that the pins are not bent or corroded.
Have a look at this

https://www.fjrforum.com/forum//index.php/topic/170314-fault-code-14-gen-ii-solved/

Similar symptoms but a different code. I assume you are not getting a Code 14 as well??

Easy to check out with the tank lifted.

I'm not getting code 14, but I'll nevertheless inspect the hose connected to the intake air sensor (since I have easy access to it right now). I should have more info/feedback some time later tonight or tomorrow.

 

[Oakdave]

if I disconnect the O2 sensor from the harness-- no code indicating "no normal signal is coming from the O2 sensor" (even though such an error code exists)

I discovered the same thing when I unplugged the O2 sensor per Power Commander recommendations. I guess the ECU doesn't really care.

It doesn't seem to care if there is NO O2 sensor but behaves badly if there is an O2 sensor that is providing incorrect information - as per my situation when I had a pinched O2 sensor wire. Might be worth seeing how it runs with the sensor disconnected.

I'll give this a try tonight (disconnect the O2 sensor)...and see if that makes any difference. I should have more info/feedback some time later tonight or tomorrow.

 

[Oakdave]

if I disconnect the O2 sensor from the harness-- no code indicating "no normal signal is coming from the O2 sensor" (even though such an error code exists)

I discovered the same thing when I unplugged the O2 sensor per Power Commander recommendations. I guess the ECU doesn't really care.

It doesn't seem to care if there is NO O2 sensor but behaves badly if there is an O2 sensor that is providing incorrect information - as per my situation when I had a pinched O2 sensor wire. Might be worth seeing how it runs with the sensor disconnected.

I'll give this a try tonight (disconnect the O2 sensor)...and see if that makes any difference. I'll also disconnect and re-seat the ECU connector (although I did that a few days ago...and all pins, etc. seemed to be in order I should have more info/feedback some time later tonight or tomorrow.

 

[Oakdave]

UPDATE: If you have read this topic from the start, then you know that this was really about trouble that my FJR was giving me at idle and very slow speeds; it felt fairly normal at speed...but idle and very low speed (under 5 mph) became the main issue. Bucking, hesitation...until it eventually got to where I had to keep the throttle open manually all the time when stopped (idle) and when coming to a stop. At one point, the engine warning light came on...but no error code. The light eventually went out (after about 10 minutes of riding). Light did not come back on. Continued riding the bike for another week after that, but the engine idle and slow speed riding got worse and worse...to where about 2 weeks ago [several weeks ago as of the posting of this update] I decided to stop using it as my regular daily commuter...and start trying to seriously troubleshoot it.

Well, after having spent about 30+ hours over the course of five consecutive weekends troubleshooting this (my only 'time off'), I was able to finally locate the problem: a small (as in truly minuscule) crack/tear in a negative vacuum hose in the throttle body unit (between cylinder 3 and 4).  That was it.  The crack was located right where the hose was connected to the nipple (just where it 'clears' the nipple).  As such, the tear/crack was about 1/4 inch from the tube's end...so all I had to do was cut the hose at that point and reattach it.  Problem solved!  Of course, a complete set of replacement hoses will take place once the order for those hoses arrives (which is on back order from Yamaha until the end of of next month (about 5 - 6 weeks from now). Fortunately, none of the other hoses are cracked (yet)...so I am keeping my fingers crossed that they'll be okay until the entire set of hoses arrives.

One take-away from this is the fact that the service manual and the various error codes that I encountered (which I attempted to troubleshoot using the service manual's 'suggestions') did nothing in terms of pointing me in the right direction.  In particular, the owner's manual states "The [check engine] warning light comes on when an electrical circuit monitoring the engine is defective."  It goes on to explain about using the self-diagnostic system (which I did, ad nauseam).  It was precisely due to that specific text--"electrical circuit monitoring the engine"--that i completely ignored first looking into something as simple/obvious as the possibility of a vacuum leak. IMO, having a vacuum leak in no way equates to having a defective electrical circuit!  

For those of you with a schadenfreude 'bent', here are the things I did before spotting the little crack in the throttle hose (the vacuum leak):

• O2 sensor replaced (just because that seemed to be the most likely culprit)
  
• Spark plugs replaced
  
• Ignition coils checked (okay)
  
• Spark plug wires/caps checked (okay)
  
• Valve clearance check. Clearances were all within normal tolerances (okay)
  
• Timing chain tensioner (okay)
  
• Timing chain guides (okay)
  
• Throttle position sensor (okay)
  
• Coolant temperature sensor (okay)
  
• Air intake temperature sensor (okay)
  
• Cylinder Identification sensor (okay)
  
• Air intake pressure sensor (okay)
  
• Fuel pump/fuel pressure (okay)
  
• Fuel injectors actuating properly (okay)
  
• Fuel injectors 'leak down' check (okay
  

Especially enjoyable was having to re-replace the valve cover (cam housing cover) twice because of me not using enough gasket sealant the first time around (which created a small gap where oil leaked out of).  Uggh!  Of course, each time meant having to drain/refill the cooling system.  Again~ uggh!

Well, I hoped you all enjoyed this pain I went through.  But in all seriousness, I do want to again thank those of you who offered me advice...and especially the video and book from dcarver (without the info I obtained from those two sources, I most likely would have unnecessarily replaced my fuel pump).  Thanks again all!  

 

[escapefjrtist]

Thanks for the update. Nice job sticking with the problem and solving it!

~G