Stuttering Power Mystery

[Folkwulfe]

This started maybe two months ago. I have an '07 109R with about 20K on her and never had a problem like this before. There have been no engine modifications at all...she's stock right down to the exhaust. Two months ago I started noticing a stutter (very mild) in the 2000 to 2200 rpm range. Kinda of a hesitation. Since most of the trips I took were short range (under 7 miles) I thought maybe there was a fouling problem. I have been told that the computer compensates too well for that to be a problem though. Spark plugs were changed last summer and K&N filters put on 6 months ago, so I know it can't be a plug or filter problem. Over the two months, things got worse. Occassionaly at stop lights, the idle rpm will go from a normal 900 to 1100-1200 range....and if I leave it alone she sometimes just dies. Firing up was immediate and blipping the throttle sometimes brought the idle back down to normal. I put her into the shop last week and they went over everything. Pressure in the cylinders is dead on the money and less than 5lbs off between them. Valves are solid and sealing properly. No pinched fuel lines and the recall fuel rail work was done several years ago just after I bought her. After a week in the shop, they were unable to reproduce what I was feeling so I got her back. Now two DAYS later and $300 poorer, it is definately getting worse. Last night she stuttered to a stop a couple of doors down from my home. I had to refire her up 4 times just to get up the driveway and into the garage. Since I get my fuel at different places (and high test only) I know bad fuel isn't it either. I am going to try the shop one more time....but I am a total loss. I don't my 9 to be a garage queen.....anybody got any ideas?

[dave340]

Did you have your fuel filter examined when you had it in for servicing? It is in the gas tank. The only other thing may be a loose ground wire...but I may be grabbing at straws there.

[MATT'sADDICTION]

No fun.

Make sure all your electrical connectors are tight and secure. It sounds like it could be an electrical issue. When your plugs were changed, who did them? I was thinking to check all the plug wires, but if the dealership did a compression check, you'd think they would make sure they were all snug. Could be a bad ground, too. Have them check the fuel filter. Although the fact that it sometimes idles high, doesn't exactly correlate with that, though the other symptoms kind of do.

You need to get it to miss when you take it in. One of the most frustrating things for both the owner and the mechanic is not being able to replicate the problem. As you know, it is extremely difficult to diagnose an intermittent problem.

Good luck.

MT

[antmor69]

Fuel filter is the first thing that comes to mind.

[Folkwulfe]

So....how often should the fuel filter be changed?

[My1st109]

2 things come to mind for me. That is 1. rectifier, 2. Magneto.

Were both of those checked?

[lucky06]

So....how often should the fuel filter be changed?

Technically there is no service intervals for the fuel filter but after the issues I had originally I try to make it a point to change it about every 10-12,000 miles just to be safe.

[lucky06]

Here is a good read for you! Its long but its got a lot of good information in it.

http://www.m109riders.com/forums/showthread.php?t=98113

[Folkwulfe]

You're a blessing Lucky....you and Jazzman. EVERYTHING you guys describe are EXACTLY what my 9 has been doing. With luck, I'll have the filter in this weekend...just in time for a veterans ride on Monday. Thanks brother!

[lucky06]

You're a blessing Lucky....you and Jazzman. EVERYTHING you guys describe are EXACTLY what my 9 has been doing. With luck, I'll have the filter in this weekend...just in time for a veterans ride on Monday. Thanks brother!

Glad to help!!

[Big-B]

Fuel filter is the first thing that comes to mind.

How are you determining the ff is not the problem?

[Folkwulfe]

How are you determining the ff is not the problem?

I have replaced the fuel filter (in the tank) with a brand new $70 filter. After nearly $400.00 total, I'm still having a stuttering problem in the lower rpm range. Since the shop couldn't repeat my problems, I started diagnosing for myself. After replacing the filter, I went on a little test run. At first I noticed a definite improvement in acceleration....however, the stuttering returned. I got to thinking....if it was a fuel starvation problem, accelerating would make it worse...right? Higher demand for fuel flow would make it worse, but it doesn't. As a matter of fact, she accelerates just fine. Twisting the throttle causes the stuttering to quit without hesitation. It seems to be isolated to cruising around 2000 to 2200 rpm and it's like a cylinder is cutting out. Sometime the rpm at idle will go up on it's own to around 1100-1200 rpm and sometimes the idle will drop too low to idle and she dies. Okay guys....back to square one.....anybody have an idea?

[godservant78]

You said changing the filter helped but then the problemreturned. I would consider running some fuel treatment thru the system. When car injectors get diry you get some similar stuttering symtoms,
only with cars, you have 4 6 or 8 cylinders to compensate for the power loss. It sounds like a fuel issue.
I would rule out anything electrical as usually if it was a wire or coil it would be iradic and cause backfires, etc. or when they get hot it will just shut down.

[Munster]

I have replaced the fuel filter (in the tank) with a brand new $70 filter. After nearly $400.00 total, I'm still having a stuttering problem in the lower rpm range. Since the shop couldn't repeat my problems, I started diagnosing for myself. After replacing the filter, I went on a little test run. At first I noticed a definite improvement in acceleration....however, the stuttering returned. I got to thinking....if it was a fuel starvation problem, accelerating would make it worse...right? Higher demand for fuel flow would make it worse, but it doesn't. As a matter of fact, she accelerates just fine. Twisting the throttle causes the stuttering to quit without hesitation. It seems to be isolated to cruising around 2000 to 2200 rpm and it's like a cylinder is cutting out. Sometime the rpm at idle will go up on it's own to around 1100-1200 rpm and sometimes the idle will drop too low to idle and she dies. Okay guys....back to square one.....anybody have an idea?

I just finished reading your thread. This may be a long shot, but has this been occurring since the spark plug replacement and k&n install....if so, check for any air leaks, especially with your airbox. The throttle body snorkels or bellows may not be properly installed, causing a lean condition during idle. An air leak will cause high idling and stalling at idle.

Good luck!

[TRod]

You might do some sensor checks. Throttle position sensor is one that might cause it.

[Folkwulfe]

The problem first cropped up prior to the replacement of the air cleaner filters with the K&N filters. It was milder, but it was there. I replaced the filters thinking they might be the problem. However, the problem only got worse in the weeks following....so I doubt the air filters are it. As far as the problem "returning"....maybe I misstated. The problem was less, but still there. The first test ride I let the bike run (at idle) for about 15 minutes till it was good and warm. It seemed to help some. The stuttering doesn't seem to be as bad when the bike is up to running temp. Today was the first "normal ride" to work I usually do and it's back roads at about 40mph for 6 miles.....not enough time to get good and hot. That is when the stuttering really makes itself known. I think the next step is the injector cleaner and see what effect it has. Acceleration may be compensating for a partially clogged injector, but idle brings it back to a near fuel starvation feeling. I'll give it a whirl and post the results. Oh....and I double checked those filters....everything re-connected properly.

[cmyk]

Did the techs at the shop do the routine tests on the ECM to see if any errors showed up? I actually had the reverse happen...idled perfectly, then on acceleration at 2500-3000rpm it stuttered and bucked like a bull. An error code showed up and it ended up being the Throttle Position Sensor (TPS). Now it runs as smooth as silk.

[Munster]

You might do some sensor checks. Throttle position sensor is one that might cause it.

The TPS sensors are not serviceable and if you remove them from the throttlebodies, you will set off codes and it will not run properly.....just ask Fire Fighter 109 out of Colorado. He had some hands on experience with TPS codes and stalling during the Vegas Meet.

I do not think that this is a TPS issue. The engine accelerates properly and has plenty of power. My money is on an air leak in the airbox or air filter snorkels.

If he removed the airbox to access the sparkplugs or removed the filter covers to change the air filters, there has to be a leak of some sort. I remember having issues installing the airbox onto the throttlebodies and making them seal and sit correctly when I had to change sparkplugs.

I guess we will have to see what transpires.

:)

[Munster]

The problem first cropped up prior to the replacement of the air cleaner filters with the K&N filters. It was milder, but it was there. I replaced the filters thinking they might be the problem. However, the problem only got worse in the weeks following....so I doubt the air filters are it. As far as the problem "returning"....maybe I misstated. The problem was less, but still there. The first test ride I let the bike run (at idle) for about 15 minutes till it was good and warm. It seemed to help some. The stuttering doesn't seem to be as bad when the bike is up to running temp. Today was the first "normal ride" to work I usually do and it's back roads at about 40mph for 6 miles.....not enough time to get good and hot. That is when the stuttering really makes itself known. I think the next step is the injector cleaner and see what effect it has. Acceleration may be compensating for a partially clogged injector, but idle brings it back to a near fuel starvation feeling. I'll give it a whirl and post the results. Oh....and I double checked those filters....everything re-connected properly.

Check the seals on both throttlebodies....the ones that connect to the airbox. I had difficulty setting them in place when I removed the airbox. You may have one or both not properly seated.

[Folkwulfe]

The spark plugs were done by the shop last summer.....I did the air filters myself. The next three days promise a good chance at rain in these here parts ( I didn't buy a jetski!!!) I'll have the time in the garage to take a good look at it.

[TRod]

The TPS sensors are not serviceable and if you remove them from the throttlebodies, you will set off codes and it will not run properly.....just ask Fire Fighter 109 out of Colorado. He had some hands on experience with TPS codes and stalling during the Vegas Meet.

I do not think that this is a TPS issue. The engine accelerates properly and has plenty of power. My money is on an air leak in the airbox or air filter snorkels.

If he removed the airbox to access the sparkplugs or removed the filter covers to change the air filters, there has to be a leak of some sort. I remember having issues installing the airbox onto the throttlebodies and making them seal and sit correctly when I had to change sparkplugs.

I guess we will have to see what transpires.

:)

Actually, the TPS sensor is testable and can be moved or replaced if needed. Page 5-41 of the service manual.

It's the secondary throttle valve actuator (SVTA) that can't be messed with.

[Folkwulfe]

Well....I have checked and rechecked those air cleaners and everything is tight and right. The airbox was never removed or loosened, but I checked anyway. All tight. I had a conversation with the original shop where I bought her 5 years ago. The shop tech seems (at least on the phone) to know what he's talking about. His first question....has it ever been plugged into the diagnostic computer to read any fault codes stored in the ECM? Answer....I have no idea. The recent trip to a closer shop makes me think they DIDN'T check the ECM.....so guess where I'm going first thing Friday morning? He also told me there are several sensors in the throttle body area talking to the ECM. One for idle, another for low rpm, and a third for high rpm....any one of them COULD be the problem. Let you know what I find out.

[MATT'sADDICTION]

There is a way to trigger your fault codes so that they show on your odometer. This is how the dealer will do it--with their special Suzuki tool. There are some threads on here of how to trigger this with a jumper wire plugged into an open connector on your bike. I've done it before when checking for my fuel injection light. Very easy and it will spit out any fault codes if they have been tripped. Then, if you have a service manual (down loadable from this site) you can look up the code and go from there. Not sure how to direct you on the search for the thread--likely in the "how to section." Try a search for "fault code tool"

So, once you figure out which one of those unused plugs on your bike is the one, you just take a small wire and stick it into each female slot. Then you turn your key to the on/run cycle and the bike will cycle through and show the culprit fault code on the odo.

This may save you some money and a trip to the dealer. Maybe someone can find the thread or show a picture of the correct plug to jump.

At least if you do this and nothing shows, then you can move onto the next idea.

MT

[MATT'sADDICTION]

Here you go:

http://www.m109riders.com/forums/sho...ght=fault+code

MT

[Folkwulfe]

Well....she's back in the shop as of last Friday. This time, however, I had a long talk with the service guy who actually RODE her and experience part of what I was complaining about. It quit on him three times going around the block. He also believes that there might be a fuel starvation problem. First is the ECM and any trouble codes that are stored in it. Then (failing that) is a flow check of the fuel pump and then on to the injectors. With luck, I'll have a good idea by Wednesday and be near back on the road again. BTW....I just made the final payment....she's all mine (literally). Ain't it the luck?

[Folkwulfe]

....and the saga continues. After over a week in the shop, they just called and have isolated PART of the problem as the ignition switch. Seems the backing plate has cracked and the switch needs to be replaced so that it will quit throwing error codes at the diagnostic computer. $137.00 and a weeks wait....then we may find out more.

[Folkwulfe]

And we have a winner!!! Picked up my 9 from the shop Saturday. Been TRYING to make her stutter as before....no soap. She purrs like brand new. So what was the final call? The ignition switch has a plastic round contact plate inside the rear of the switch housing. This plastic disk has the actual contacts for start and power....some contacts have a resistor soldered between them. These are necessary to prevent someone from cutting wires and "hot wiring" the bike to run without the key (theft prevention). Mine had a crack in the plastic disk that, when the engine reached a certain rpm, the vibrations made the contacts separated enough to cause the switch to go "on" to "off" and back on several times. No fault code registered because it saw the event as a "key on to key off to key on". This made the engines falter and sputter in the 2000-2200 (about 40 mph) range. As the crack got worse, the faltering and stuttering also got worse. The switch was replaced and she runs like a champ again. So.....if you have a stuttering problem and the shop sees a few random ignition switch fault code crop up....check the switch disk!

[rnspark]

So the problem showed up as a ignition key code even though you knew the key was physically switched on. Is that correct

[The HUFF]

Actually, the TPS sensor is testable and can be moved or replaced if needed. Page 5-41 of the service manual.

It's the secondary throttle valve actuator (SVTA) that can't be messed with.

Wanna bet? It is serviceable, but very touchy and a very specific procedure that I still don't know. I was there for that situation Pete described. It was a nail-biter and almost disabled 2 nines!

[The HUFF]

And we have a winner!!! Picked up my 9 from the shop Saturday. Been TRYING to make her stutter as before....no soap. She purrs like brand new. So what was the final call? The ignition switch has a plastic round contact plate inside the rear of the switch housing. This plastic disk has the actual contacts for start and power....some contacts have a resistor soldered between them. These are necessary to prevent someone from cutting wires and "hot wiring" the bike to run without the key (theft prevention). Mine had a crack in the plastic disk that, when the engine reached a certain rpm, the vibrations made the contacts separated enough to cause the switch to go "on" to "off" and back on several times. No fault code registered because it saw the event as a "key on to key off to key on". This made the engines falter and sputter in the 2000-2200 (about 40 mph) range. As the crack got worse, the faltering and stuttering also got worse. The switch was replaced and she runs like a champ again. So.....if you have a stuttering problem and the shop sees a few random ignition switch fault code crop up....check the switch disk!

WOW! That is AMAZING! Talk about finding the needle in the haystack! Good job!