07 Busa With Rough Idle And Hanging Revs
- Thread starter Shaun Ketterman
- Start date
Shaun Ketterman
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Quoting you guys simply to get your attention :-)
Just picked the bike up from the dealer. Valves were slightly out of spec (only a few of them), so they addressed that, and they also discovered a few things:
1. One culprit in my rough idle was an intake leak. The clamps that hold the airbox down on top of the intake tubes were not tightening the airbox tubes enough to properly seal (I could tighten them plenty, just not sealing), creating a massive intake leak. So the idle is better, still off though. Revs still hang at 2 grand.
2. I don't recall the exact name, but there is some seal inside of my fuel pump that they somehow ascertained is leaking, their recommendation was to replace the pump, which, coincidentally, I had already planned to do. I guess testing the fuel pressure at this point is moot. I may do it anyway to compare the current one with the new one, and just to say that I've done it before.
3. I think they are called steering bearings..whatever the bearings that are in/under the triple tree. Mine need to be, at least, repacked, and are possibly notched and need to be replaced. I had noticed the clunking when going over bumps/dips/pulling into the driveway, but always just assumed it was how Busa's are. They quoted me $90.00 OTD to repack the bearings, or $300.00 if they need to be knocked out and replaced. It was advised that I ride the bike as little as possible until it gets fixed. Does that all sound about right?
4. I just replaced my fork seals (oil seal and dust cap) 2 weeks ago, and now my right fork is leaking horribly. I noticed it yesterday and had planned to just clean it, but the amount of oil almost seems like the seal came loose. Since I REALLY don't want to tear the fork apart and go through that headache again, they are going to take care of it for me for another $170 OTD.
5. They discovered that the line from the gas tank that is there to release pressure was coiled up on the frame, when it should be routed down toward the ground, same thing with my coolant overflow line. They re-routed those. I can't help but wonder if my gas cap was leaking due to that? Too much pressure maybe?
6. They also replaced a handful of missing fairing bolts, which was a kind gesture.
The good news, is that the guy who did the work has been working on Busa's since their invention. The dude at the desked joked that he's torn down more Busa's than Suzuki lol. It's good to at least know the guy doing the work is experienced.
Shaun Ketterman
Registered
Sorry for the double post.
David Offor
Registered
Good update.
So, they didn't get to the bottom of the hanging throttle or the uneven tick over?
Is it a significant improvement, with the running, after they worked on it?
Did he say if the 'slightly out of spec' valve clearances would make the bike run rough?
If you are syncing the throttle bodies, to get smooth idle, good running the air box is off anyway (huge air leak), so I don't think non sealing clamps around the air box, is a major worry.
Was it definitely air box clamps and not the rubber sleeves, that connect the throttle bodies to the cylinder head, that were sucking air?
Did the busa guru indicate that it will be sorted, if the pump is changed?
Sounds like you have a few other problems to get fixed.
So, they didn't get to the bottom of the hanging throttle or the uneven tick over?
Is it a significant improvement, with the running, after they worked on it?
Did he say if the 'slightly out of spec' valve clearances would make the bike run rough?
If you are syncing the throttle bodies, to get smooth idle, good running the air box is off anyway (huge air leak), so I don't think non sealing clamps around the air box, is a major worry.
Was it definitely air box clamps and not the rubber sleeves, that connect the throttle bodies to the cylinder head, that were sucking air?
Did the busa guru indicate that it will be sorted, if the pump is changed?
Sounds like you have a few other problems to get fixed.
Those prices are great, and at a dealer.
And they know what they're doing.
That's unheard of.
And they know what they're doing.
That's unheard of.
Shaun Ketterman
Registered
David,
Lot's of good questions! I actually didn't ask them/tell them much about the rough idle. I mentioned it, of course, and the bucking/surging at low RPM, and they mentioned after they were done that the airbox clamps would make an improvement (which it did). I would *not* call it significant though, just 'better'. When I rev it, the engine speed goes down MUCH faster, but now it hangs at 2 grand almost every time. They didnt seem to think the valves were out of spec nearly enough to warrant my issues. As I'm typing this, I cant confirm that it was the clamps, vice the actual intake boots, that were the cause. I'm about to go into the garage to do another TB sync, and while I'm down there, I'll test those boots. Also, I didn't even get to talk to the guru type, as he was on his lunch break when I got there. The compression tool I ordered (thank you for the info on 10mm adapter info) will be here sometime before 8pm. Once it gets here I'm going to test each cylinder and will put those numbers up.
Also, after the valve adjustment, there seems to be a new thing - when I put the bike in neutral the engine speed increases by like 500 RPM! If this is something I can address myself, I will, but I intend to ask them about it tomorrow.
Yeah man, and this location (Vey's Powersports in Lemon Grove, San Diego, for those who may be in the area) was by far the cheapest. Nearly every other quote I got for the valve adjustment was well into the 600's, some were over 700. The dude even admitted that the other quotes may have included some other things like oil/filter change, new plugs, etc, as those are apparently a common inclusion with the valve adjustment. Since I literally JUST did those things, they took them off the bill. I can appreciate their honesty though.
Shaun Ketterman
Registered
Alright, so I just completed a compression test on all 4 cylinders. Results have me antsy...I'm *praying* that I need to simply calibrate this gauge...but my compression readings are $%^& low.
-Engine was at running temp
-All spark plugs removed
-Clutch in while starting
-Throttle wide open while starting
-Fuel pump connector disconnected
-Battery charged
Cylinder 1 Reading
Cylinder 2 reading:
Cylinder 3 reading:
Cylinder 4 reading:
No explanation necessary. If the gauge is accurate, my compression is grossly low across the board.
Clymer service manual shows standard @ 174-232 PSI (Service Limit 131 PSI...whatever that means). I'm showing ~115 PSI on all 4.
The only thing that gives me hope is that they are all 4 virtually identical. Is it fathomable that all four cylinders have worn down to this degree at the exact same rate??
This gauge cost me 25 bucks on Amazon.
poop.
Just now read the reviews on this thing and most are complaining that it is extremely inaccurate. Well...I may have wasted money but that gives me some relief. Maybe I'll ask the guys over at the dealership if I can 'borrow' their compression gauge and test myself. Urgh. I was seriously at the point in my mind that I wanted to get rid of this bike.
-Engine was at running temp
-All spark plugs removed
-Clutch in while starting
-Throttle wide open while starting
-Fuel pump connector disconnected
-Battery charged
Cylinder 1 Reading
Cylinder 2 reading:
Cylinder 3 reading:
Cylinder 4 reading:
No explanation necessary. If the gauge is accurate, my compression is grossly low across the board.
Clymer service manual shows standard @ 174-232 PSI (Service Limit 131 PSI...whatever that means). I'm showing ~115 PSI on all 4.
The only thing that gives me hope is that they are all 4 virtually identical. Is it fathomable that all four cylinders have worn down to this degree at the exact same rate??
This gauge cost me 25 bucks on Amazon.
poop.
Just now read the reviews on this thing and most are complaining that it is extremely inaccurate. Well...I may have wasted money but that gives me some relief. Maybe I'll ask the guys over at the dealership if I can 'borrow' their compression gauge and test myself. Urgh. I was seriously at the point in my mind that I wanted to get rid of this bike.
David Offor
Registered
Because all the readings are the same, I'd say it's probably the tool that is at fault, I can't imagine all cylinders have worn exactly the same, try another gauge And it would take uneven readings, to give you your symptoms, I think.
I'm surprised they didn't preform a throttle body sync, after doing the valve adjustment, it's also surprising that they gave the bike back, still not running right or didn't at least offer an explanation for the hanging revs and poor idle.
The revving up, once in neutral, is interesting, there is a gear position sensor but I don't know much about it, it may be worth asking the shop or someone here, if that could cause engine running problems.
P.s send that gauge back, if the reviews are bad
Shaun Ketterman
Registered
Did a ton of testing tonight with a multimeter, and want to throw up the results for input/clarity/etc. This is going to be a TON of data :-)
The first issue is the data on continuity tests. My multimeter manual states the device will beep if there is no resistance. It worked like this on a few occasions, then when I went BACK to a given sensor to retest, there was no beep, so I'm not 100% sure that any of the continuity results are accurate. The bike is still in pieces in the garage, so I will give it a go again tomorrow morning.
***SUMMARY***
Summarization of each component as follows. Details on each are in the post below!
* VCSV, Vacuum Damper, VTV, and Intake Air Control Valve Actuator passed all tests in the service manual
* Injectors passed the resistance and continuity tests; I cannot perform the voltage test (need smaller probes to fit inside the connectors)
* TPS failed resistance test, and continuity test. INPUT Voltage tests were good; OUTPUT voltage tests could not be completed (lack of knowledge)
* AP Sensor - INPUT voltage tests PASS; OUTPUT voltage test and vacuum tests could not be completed due to lack of tools/skills/knowledge
* Camshaft Position Sensor - Resistance PASS; Continuity FAIL; Peak Voltage could not be completed due to lack of tools/skill
* IAPS - INPUT voltage PASS; Vacuum test cannot do due to lack of tools/skills
* Battery - Voltage PASS (13V)
* Ignition Coils - Resistance PASS; Peak Voltage cannot do due to lack of tools/skills.
Lots of things still up in the air; looks like TPS may be bad
*** END SUMMARY***
All of this was done IRT my hanging revs/rough idle. I figured I'd test as many of the sensors as I could to eliminate them as causes. Results are ## (##) where first numbers are my results, numbers in parenthesis are service manual numbers.
1. Vacuum Control Solenoid Valve (VCSV)
-Resistance test - 38.2 ohms (36-44 ohms)
2. Vacuum Damper
-Only test is a visual inspection, which mine passes.
3. Vacuum Transfer Valve (VTV)
-Only test is to blow in each end (black and orange end) to see if air passes through
-Air passes through when blowing through the orange side (good)
-Air does not pass through when blowing through the black side (good)
4. Intake Air Control Valve Actuator
-This is a 'flap' that is on the top side of the air box. When vacuum is applied, it closes. I used a Mityvac to apply vacuum as the manual described, and the valve closed as designed.
5. Injectors
a. Resistance Test:
Injector 1 - 14.4 ohms (11-16 ohms)
Injector 2 - 14.6 ohms (11-16 ohms)
Injector 3 - 13.8 ohms (11-16 ohms)
Injector 4 - 13.8 ohms (11-16 ohms)
b. Continuity test
-My multimeter beeps if there is no resistance, which for this test, should be the case.
-All injectors beeped to indicate zero resistance (pass)
c. Voltage Test
-I was unable to perform these tests (which I feel are the most important) because the leads on my multimeter will not fit inside the connectors. I have a device from motion pro on the way that can test if they power on and spray, as well as clean them out properly, so I'm not too concerned here (yet).
6. TPS
a. Resistance (throttle closed): 1.16k (manual shows 1.3k)
b. Resistance (throttle wide open): 3.9k (manual shows 4.5k
so these number indicate my TPS is off in the resistance category. The manual states that if the tested numbers are not within spec, per the book, to replace the sensor. Your thoughts?
c. Continuity - Was good initially, but I cannot repeat it. So for now, this test has failed.
d. Input voltage (blue wire (positive lead) and ground (black lead) - 5.13V (4.5-5.5V)
e. Input voltage (blue wire (positive lead) and black wire (black lead) - 5.07V (4.5-5.5V)
f. output voltage - not sure how to do this. Manual says to connect the wire to the sensor, but then to somehow connect probes to the sensor?
7. Atmospheric Pressure (AP) Sensor
a. input voltage: red wire/ground - 5.1V (4.5-5.5V)
b. input voltage: red wire/black wire - 5.0V (4.5-5.5V)
c. output voltage - same as TPS. I need some form of 'back probe pins'.
d. vacuum test - no clue how to test this. From the manual: "Connect three new 1.5-volt batteries in series as shown in Figure 97. Measure the total voltage of the batteries. The voltage should be 4.5-5 volts. There are more steps, but I can't even do this one...
8. Camshaft Position Sensor
a. Resistance: 1.1k ohms (0.9-1.3k ohms)
b. Continuity: No beep from multimeter
c. Peak voltage - need a peak voltage tool to complete?
9. Intake Air Pressure Sensor (IAPS)
a. Input voltage (red wire/ground): 5.13V (4.5-5.5V)
b. Input voltage (red wire/black wire) 5.0V (4.5-5.5V)
c. Vacuum test: Cannot do. This is the same poop with three 1.5V batteries in series, and then a bunch of other steps.
10. Battery
a. Voltage - 13V
11. Coils
a. Resistance:
Coil 1: 1.3 ohms
Coil 2: 1.4 ohms
Coil 3: 1.4 ohms
Coil 4: 1.3 ohms
All coils should be between 1.0-1.6 ohms
b. Peak Voltage: Need either a "multicircuit tester" or "peak voltage adapter" again. Also it would seem that I need additional spark plugs to test.
The first issue is the data on continuity tests. My multimeter manual states the device will beep if there is no resistance. It worked like this on a few occasions, then when I went BACK to a given sensor to retest, there was no beep, so I'm not 100% sure that any of the continuity results are accurate. The bike is still in pieces in the garage, so I will give it a go again tomorrow morning.
***SUMMARY***
Summarization of each component as follows. Details on each are in the post below!
* VCSV, Vacuum Damper, VTV, and Intake Air Control Valve Actuator passed all tests in the service manual
* Injectors passed the resistance and continuity tests; I cannot perform the voltage test (need smaller probes to fit inside the connectors)
* TPS failed resistance test, and continuity test. INPUT Voltage tests were good; OUTPUT voltage tests could not be completed (lack of knowledge)
* AP Sensor - INPUT voltage tests PASS; OUTPUT voltage test and vacuum tests could not be completed due to lack of tools/skills/knowledge
* Camshaft Position Sensor - Resistance PASS; Continuity FAIL; Peak Voltage could not be completed due to lack of tools/skill
* IAPS - INPUT voltage PASS; Vacuum test cannot do due to lack of tools/skills
* Battery - Voltage PASS (13V)
* Ignition Coils - Resistance PASS; Peak Voltage cannot do due to lack of tools/skills.
Lots of things still up in the air; looks like TPS may be bad
*** END SUMMARY***
All of this was done IRT my hanging revs/rough idle. I figured I'd test as many of the sensors as I could to eliminate them as causes. Results are ## (##) where first numbers are my results, numbers in parenthesis are service manual numbers.
1. Vacuum Control Solenoid Valve (VCSV)
-Resistance test - 38.2 ohms (36-44 ohms)
2. Vacuum Damper
-Only test is a visual inspection, which mine passes.
3. Vacuum Transfer Valve (VTV)
-Only test is to blow in each end (black and orange end) to see if air passes through
-Air passes through when blowing through the orange side (good)
-Air does not pass through when blowing through the black side (good)
4. Intake Air Control Valve Actuator
-This is a 'flap' that is on the top side of the air box. When vacuum is applied, it closes. I used a Mityvac to apply vacuum as the manual described, and the valve closed as designed.
5. Injectors
a. Resistance Test:
Injector 1 - 14.4 ohms (11-16 ohms)
Injector 2 - 14.6 ohms (11-16 ohms)
Injector 3 - 13.8 ohms (11-16 ohms)
Injector 4 - 13.8 ohms (11-16 ohms)
b. Continuity test
-My multimeter beeps if there is no resistance, which for this test, should be the case.
-All injectors beeped to indicate zero resistance (pass)
c. Voltage Test
-I was unable to perform these tests (which I feel are the most important) because the leads on my multimeter will not fit inside the connectors. I have a device from motion pro on the way that can test if they power on and spray, as well as clean them out properly, so I'm not too concerned here (yet).
6. TPS
a. Resistance (throttle closed): 1.16k (manual shows 1.3k)
b. Resistance (throttle wide open): 3.9k (manual shows 4.5k
so these number indicate my TPS is off in the resistance category. The manual states that if the tested numbers are not within spec, per the book, to replace the sensor. Your thoughts?
c. Continuity - Was good initially, but I cannot repeat it. So for now, this test has failed.
d. Input voltage (blue wire (positive lead) and ground (black lead) - 5.13V (4.5-5.5V)
e. Input voltage (blue wire (positive lead) and black wire (black lead) - 5.07V (4.5-5.5V)
f. output voltage - not sure how to do this. Manual says to connect the wire to the sensor, but then to somehow connect probes to the sensor?
7. Atmospheric Pressure (AP) Sensor
a. input voltage: red wire/ground - 5.1V (4.5-5.5V)
b. input voltage: red wire/black wire - 5.0V (4.5-5.5V)
c. output voltage - same as TPS. I need some form of 'back probe pins'.
d. vacuum test - no clue how to test this. From the manual: "Connect three new 1.5-volt batteries in series as shown in Figure 97. Measure the total voltage of the batteries. The voltage should be 4.5-5 volts. There are more steps, but I can't even do this one...
8. Camshaft Position Sensor
a. Resistance: 1.1k ohms (0.9-1.3k ohms)
b. Continuity: No beep from multimeter
c. Peak voltage - need a peak voltage tool to complete?
9. Intake Air Pressure Sensor (IAPS)
a. Input voltage (red wire/ground): 5.13V (4.5-5.5V)
b. Input voltage (red wire/black wire) 5.0V (4.5-5.5V)
c. Vacuum test: Cannot do. This is the same poop with three 1.5V batteries in series, and then a bunch of other steps.
10. Battery
a. Voltage - 13V
11. Coils
a. Resistance:
Coil 1: 1.3 ohms
Coil 2: 1.4 ohms
Coil 3: 1.4 ohms
Coil 4: 1.3 ohms
All coils should be between 1.0-1.6 ohms
b. Peak Voltage: Need either a "multicircuit tester" or "peak voltage adapter" again. Also it would seem that I need additional spark plugs to test.
David Offor
Registered
Great testing, your TPS sounds dodgy and is certainly linked to bad running problems.
Do you have anyone who would let you swap/borrow sensors, known good running parts?
Do you have anyone who would let you swap/borrow sensors, known good running parts?
David Offor
Registered
Lol, hello. Yes, I think over this amount of time, I deserve some positive progress, can't remember ever riding the bike, without an issue.
Shaun Ketterman
Registered
The service manual explicitly states that I should replace the TPS due to those numbers. I don't have any friends out here who ride (I'm kind of a lone wolf type of guy I guess). I see a bunch of used TPS sensors on Ebay, but I'm not sure if a used one is the best idea? The cheapest NEW sensor I've found online is 140 USD (~111 pounds).
Are you good with electrical stuff? I have a question regarding continuity. Multimeter is in continuity mode. As you know, our injector connectors are 2-pin. So the service manual says to test continuity on each pin in the injector with a 'good ground', and if the test is good, the multimeter will beep. So I put the positive lead from my multimeter on one of the injector pins, and place the black lead from the meter onto something that is ground...except I can't seem to find a ground that works. I've tried the bike frame, the negative battery terminal, my garage floor, a bunch of stuff, nothing seems to show that there is good continuity.
Then, after a minute, I decided to take both leads from my meter, and put them on the 2 pins in the injector simultaneously. This caused my meter to beep, showing (presumably) good continuity? If the ohms measurement is within spec, which all my injectors are, shouldn't continuity also be good?
In any case, I decided that next weekend I'm going to tackle the fuel pump. The new pump is here, as is the new filter strainer. My injector tester should be here around Thursday, so I figured I can do it all at once. If I'm still having issues after I do all of that, the TPS is the only thing left that I have found that could cause the rough idle/hanging revs. If none of that works, I'm in the dark :-/
Shaun Ketterman
Registered
Shaun Ketterman
Registered
Hey gents, quoted you guys again to give an update and get your input!
So I may have found the cause, so to speak, for the hanging revs:
(Bike is normal op temp, fast idle is off)
1. I accelerate on the freeway up to 60MPH. Get to 6th gear, pull clutch in. Revs fall down at a decent speed, but then 'hang' at 2000RPM. No amount of revving will get the idle back down to the set speed of 1200RPM.
2. I continue coasting with the clutch pulled in. I click down into 5th gear position (clutch remains pulled). Nothing changes.
3. I click down into 4th gear, clutch still pulled in. Revs instantly fall to normal idle speed!
4. While STILL coasting, I proceed to click down into each gear, all the way down to 1st, NEVER releasing the clutch. All gears below 4th keep the idle at 1200.
5. Since I'm slowing down quite I bit, I accelerate back up to 70MPH in 4th gear, pull clutch. Revs fall down to normal idle!
6. I click up into 5th gear, clutch remains pulled. Revs surge back up to 2000!
7. I click back down into 4th, clutch still pulled, revs fall back down!
Through this entire process I want to stress that I NEVER release the clutch and NEVER apply throttle. What the actual fxck is going on?? Basically, when I click into 5th or 6th, my RPMs automatically go UP from 1200 to 2000, with the damn clutch in! All other gears, revs fall down to normal idle speed. I did this over and over and over (and over) to be absolutely certain. It is always the same.
I do note that the speed that my revs fall slows a bit once they fall to about 2000RPM in 1st through 4th. The slowdown is slight, but noticeable. Since my idle is still really funky, I believe that is what I am seeing, and the rev's would fall just as quickly down to idle if the idle itself was stable. So as far as I can tell at this point, my engine speed will decrease normally, I just need to learn why 5th and 6th gear causes it to hang at 2000RPM.
With all of that said, I want to get your guys input on the latest TB sync I did.
Here is a video of how it looks at IDLE. As you can see, the gauges are just crazy, impossible to adjust with any amount of accuracy.
And here is how it looks around 3000RPM. This is as close as I could get them.
If you watch the full 30 seconds of the 2nd video, take note on how much my idle changes during the video. I'm not touching ANYTHING the entire time. Cylinder #2 goes as low as ~25.5, and as high as just under 28, and cylinder 3 goes as low as 26, and as high as 28.5. I don't know if that is normal, but it seems like a pretty steep change in engine speed, definitely not solid.
Also, often times when I adjust #1 and 2, the engine speed will surge up to 4000+. I'm being VERY careful to not put any pressure on the adjuster, as I know this causes that. It seems like just the weight of my screwdriver is enough to do that, and it is NOT heavy. Getting them all level is a real pain, and it is made even more difficult by the fact that my idle is all over the place. The overall level of cylinder 2 goes both below AND above cylinder 1 without me touching anything. So it's like, where the hell to I set it? The same goes with #3 - it goes both below and above the level of 4, so it's virtually impossible to get them level together.
As always, any and all input you guys have is greatly appreciated!
Shaun
David Offor
Registered
Those readings suggest an air leak but youve eliminated that possibility, also, fluctuating fuel delivery could also cause it.
Try swapping the injectors around (note which one was and now is in each cylinder), see if your bad cylinder moves to another.
Faulty injectors could cause hanging revvs and a throttle that is impossible to sync, if it was low pump pressure, i don't think it would fluctuate on your readings and I don't think it would cause your throttle to 'hang'.
Try swapping the injectors around (note which one was and now is in each cylinder), see if your bad cylinder moves to another.
Faulty injectors could cause hanging revvs and a throttle that is impossible to sync, if it was low pump pressure, i don't think it would fluctuate on your readings and I don't think it would cause your throttle to 'hang'.
Shaun Ketterman
Registered
I wouldn't necessarily say that I've completely eliminated an air leak, but I have replaced most of the factory vacuum lines, and I've sprayed a ton of carb cleaner around all the connecting and fittings with no audible change in idle. A bad sensor is still possible too..urgh.
This is a good idea, and I will give it a go when I take them all out for cleaning.
I don't think the injectors are causing the hanging revs at this point. I don't have any clue WHAT it is though. ECM maybe? How would you explain the revs going up to 2000 when I just click into gear (clutch pulled in and no throttle applied)? And the fact that it only does it in 5th gear position and 6th gear position? Actually it does it in neutral every once in a while too. To me, that seems more like a bad sensor...but man I honestly can't fathom this one.
