Victory Motorcycle Forum banner
61 - 80 of 80 Posts

·
Registered
Joined
·
4,938 Posts
Ground by ECM checked out OK. Took for a spin and about 20 min or so idle dropped off a little. Gradually got worse and started the fluxing. I tried the spray ECM, TPMS and IAC with the dust off computer air. No change. So scratching head I disconnected the plug at IAC and idle returns to stable and about 900 RPM.
Interesting, what are your thoughts?
The ECM is turning the idle point down ? Does that sound correct?
 

·
Premium Member
Joined
·
2,901 Posts
Interesting, what are your thoughts?
The ECM is turning the idle point down ? Does that sound correct?
Can you leave it unplugged?
 

·
Registered
Joined
·
1,293 Posts
Discussion Starter · #63 ·
My thought is the IAC is bad. Compensates for awhile then looses its mind maybe. Although if the stuff I read I understand rite the ECM is supposed to have the memory setting. Thats not to say that the IAC is responding correctly. If it runs OK with it disconnected either A: I caught it at the rite spot and it idles rite or B: the valve is bad and just will ocasionaly reset. Either way I contacted the seller and sent him the information he requested. I ran OK coming home for 10 or 15 minutes, although the check engine light was on.
 

·
Registered
Joined
·
4,938 Posts
I believe your right that the IAC has no processor or memory but just a stepper motor. But that doesn’t mean it couldn’t be a problem. Engine management is a complex system.

If the IAC is a dead end see if you can get the problem to repeat.

If I do this then the IAC responds this way, causing this, but it needs to be in this temperature range for it to happen. Or have been driven this way Etc. You’ll probably need a cheap heat gun and a notebook, to keep track of the temperature outside when you ride, engine temperature etc. Type of driving.
Then spend some time trying to make sense of what is happening.

If you can determine when it does it enough to explain it then I would call someone who uses the Maximus software. I don’t know much about that software but I believe it accesses the ecm maps directly . I’ve used similar software on HD’s. Playing with it you get a pretty good feel for how the ecm takes data in and uses it to control the engine, which tells you where to look when things stop reacting the way they should.

If you can explain the issue clearly, someone familiar with what inputs effect the IAC stepper and all of what the designers have it doing may be able to suggest a sensor or couple of sensors that might not test bad but have drifted from their calibration enough that in combination might cause the problem you are experiencing. Or something like that.

Another thought is
I believe these bikes use a map sensor as a mass air sensor. Be sure to double check that. I’m pretty sure but not positive.

Perhaps the IAC is closing to compensate for a change in manifold pressure from an intermittent small air leak that is changing the absolute press at idle.

I wonder if there is a air leak that is temperature dependent or vibration dependent . Not certain what that would be or where. Perhaps the map sensor itself as a possibility. Might be at the end of it’s life, or developed a sensitivity to heat or vibration?

There are automotive ones that can be substituted that are cheaper than a factory one for testing purposes.

You test for air leaks with propane, (safe way), or starter fluid. But a leak that comes and goes , I’m not sure how you check for that. You’ll have to get creative.




I am just throwing out ideas. They may or may not be useful. You might find some info poking around the mega squirt site that might point you in the right direction, too. I haven’t been over there in years but they had some very helpful info there in the past.

One last thought. disconnect the battery then disconnect the ecm connector and inspect both sides for corrosion or condensation. Either are problematic.

Eventually you will get to the bottom of it, hang in there.
 

·
Registered
Joined
·
1,293 Posts
Discussion Starter · #65 ·
So, I have been able to repeat many times. Both with orginal valve and this one. It did apear (if go back in this thread) it worked OK for a short period of time. I hqve run about every diag in the Victory shop manual a fellow can do without the majic wrench program and scan tool. I have done pin out test on harness from ECM to IAC, TPMS fuel injectors , grounds, new battery, new R&Rectifier. Basicly anything dealing with air fuel mixture. It pops, backfires out exhaust more than what I think it should on decel. I do have the thrush mod mufflers, but it has run fine with those for years before this cropped up. The IAC dont seem to cycle as long now on "set up" as previously. Although I can not positively point to that as I have not timed it. Found ECM that will work on bike, but have not dug into whether the majic wrench thing has to be used to allow bike to see it. Or if its plug and play. Auto manufacturers have those soooo tied up. Heck Dodge has a security system buit in and you cant even use a scan to to get codes without a bypass plug.
 

·
Registered
2012 Victory Cross Country Tour, Indianapolis
Joined
·
3,411 Posts
Two bad IAC? 🤷‍♂️
 

·
Registered
Joined
·
1,293 Posts
Discussion Starter · #67 ·
Yea I know. OEM bad and replacement? But my OEM regulator was slightly wacky (not really enough to warrant change) Had a voltage pulse or something the charge system machine didnt like. And being I had read that the CAN bus on bike was picky I changed it. The replacement was worse yet and allowed charging @ 18vdc. So had to replace it too. Just my luck lately.
 

·
Registered
Joined
·
4,938 Posts
Have you sprayed a little starter fluid around the throttle body to manifold area to rule out an air leak?
Very little. Some starter fluid cans will accept a straw. Engine races or changes idle == air leak of some sort or you sprayed enough that vapor came into motor through air intake and filter.

Propane is also good, a little more controllable if you have access to a plumbers torch, the type with the hose like this. https://www.amazon.com/Propane-Weld...d_wg=yE0HS&ref_=pd_gw_ci_mcx_mr_hp_atf_m&th=1
 

·
Registered
Joined
·
1,293 Posts
Discussion Starter · #69 ·
Yes I have done the spray around intake parts. No change. But my thought was what if because of thermal rate of expansion of the different compounds materials, after it heats up then the lower gasket has a slight leak. But when I came home and it was all warmed up I used brake clean and sprayed. No change.
 

·
Registered
Joined
·
4,938 Posts
Yes I have done the spray around intake parts. No change. But my thought was what if because of thermal rate of expansion of the different compounds materials, after it heats up then the lower gasket has a slight leak. But when I came home and it was all warmed up I used brake clean and sprayed. No change.
The chlorinated brake clean (red can) is incredibly deadly should it pass through a flame, arc , or a combustion engine. It should never be used to clean anything intended to be welded or heated. One wiff of the exhaust or some of the fumes where the brake cleaner had seeped into a crack or porous section that gets welded near producing fumes and should you survive, your lungs would be permanently scared and your life would suck from then on. Too many people have had this experience. The only option is to hope for a lung transplant.


I‘ve always used starting fluid a it works well provided the motor isn’t having backfiring issues.
I do it outside with a good fire extinguisher setting right next to the bike ready to go.
Never needed it, but just in case.

Back to the bike.
Is this what it is doing? You pull the clutch in too long while the bike is in motion with the throttle closed and when you turn the throttle back on as you move it the motor drops out or stops?
Your sitting at a light. You try to go but the motor dies instead? Just out of the blue?

You never noticed this until sometime after the exhaust was modified? Correct?
 

·
Premium Member
Joined
·
2,901 Posts
" I checked the battery when I first got it and machine never liked it. Rite out of box it said battery had like 13.2vdc but " replace battery". So something fishy there. Load test good and all that. So I went with it."

It failed the test. Take the battery somewhere to get tested.
 

·
Registered
Joined
·
1,359 Posts
I'm following your efforts with interest and with everything you've done I think it's time to pass it over to the pro's and hopefully have everything ready to go for the upcoming riding season. (is there one in Florida other than year-round?) As I'm sure you've already checked, Florida has a number of outlets more than qualified to do the work. Some of them like the Indian and Polaris dealers will also have access to the Digital Wrench. They can read the codes but whether or not they will be willing or capable of helping you is questionable. Like some tuners, they may not be competent to work on anything except one line of motorcycle. It certainly wouldn't hurt to make a few phone calls.

Some, but not all Lloyd’z U.S. Dealers | LLOYD'Z Motor Workz
 

·
Registered
Joined
·
1,293 Posts
Discussion Starter · #73 ·
No codes. No error message. The folks I got the IAC from are taking it back to test. I have been thinking for awhile now I may have to just throw in the towel.
 

·
Registered
Joined
·
4,938 Posts
I think you may have too problems.
The surge sounds like your bike is lean in the rpm range that it surges in due to changing the exhaust.

The stalling or almost stalling is a problem to do with a issue that plagues a relatively small group of Vic’s when you make the exhaust less restrictive.
They are both fixable. It does involve the IAC. But the IAC isn’t necessarily broke. It’s responding to the ecm. Responding as instructed. The problem has to do with a routine that keeps the Cat’s hot as far as I have been able to tell. The IAC is overly large because it is used to send O2 to the cats, either on the overlap of the cam or by shutting off the injectors when the throttle is completely closed. Hence the “Vic pop” heard when you roll the throttle off hard.

That’s what I’m starting to think.
Your really frustrated because nothing is actually broken per say. It’s not working as a system.

When an engine is to lean it adversely effects the timing of the combustion.
See this article for an not bad explanation of combustion timing.
That is likely the shudder or surging your feeling at certain rpm.
 

·
Registered
Joined
·
1,293 Posts
Discussion Starter · #75 ·
The exhaust has been on for well over 2 years. This problem has cropped up say about August or so. I have been on a household move hold doing anything for a month or so. Only recently got to do a little work. The CATS are plenty hot. LOL I have also ran it with CATS disconnected. Have not tried CAT disconnected since this has started. They are only the single wire jobs.
 

·
Registered
Joined
·
4,938 Posts
The exhaust has been on for well over 2 years. This problem has cropped up say about August or so. I have been on a household move hold doing anything for a month or so. Only recently got to do a little work. The CATS are plenty hot. LOL I have also ran it with CATS disconnected. Have not tried CAT disconnected since this has started. They are only the single wire jobs.
I have two bikes my wife’s XR and my XC that developed the stall issue after we had modified mufflers put on them by az dealer. My wife’s did it really bad. To the point she was hesitant to ride it.
She is a great rider with 3 or 4 hundred thousand miles under her belt. I knew it wasn’t her.
One day I was riding her XR and it did it to me as I completed a slow city corner. It was as if I had hit the kill switch. Pulled in the clutch hit the starter and it fired right up with out drama.

I thought my XC was immune but it wasn’t. It would do it under the right circumstances and did. Almost took me out twice before I found a way around it.

I read through your first several posts on this thread, but I am still a little confused as to the symptoms you described. Is your bike prone to stalling or stumbling occasionally when the throttle has been closed, turned to the zero position, then you turn it up and find it’s stalled? Our‘s did it especially if the clutch was pulled in at the same time.
As an example you pull out into an intersection looking for a break in traffic, you pull the clutch in.
The bike is now idling and coasting, you see a gap coming up, you roll on the throttle and release the clutch and the engine is no longer running. Something like that? Could what your bike is doing pass for that? Or is it something different.
 

·
Registered
Joined
·
1,293 Posts
Discussion Starter · #77 ·
Runs what ai would discribe as "normal" except for some deceleration poping it has done for very long time. Then after running normal after the 20 or 30 min time frame, pull up to a stop and idle usually drops a 100 or so rpm. Then a little mor time goes by say 5 or 10 min rpm will be low enough engine surges or cycles enough you can hear rods rattle. Eventually engien just cant maintain idle @ 3-400 rpm and quits. Seems to run hotter as rpm decreases but 5hat could be my imagination. It will be hard to start and not roll over fast. Sometimes a reset procedure will get it back to able to idle correctly for a few minutes, but lately not so much. So I hold throttle open for higher rpm or rev at light to keep above idle range.
 
  • Like
Reactions: Joe_

·
Registered
2012 Victory Cross Country Tour, Indianapolis
Joined
·
3,411 Posts
Sounds similar to how my bike was doing before replacing battery. When it's idling bad is your volt meter really low?
 

·
Registered
Joined
·
1,293 Posts
Discussion Starter · #79 ·
Nope between 12 and 14. New regulator. Stator puts out required ac volts
 

·
Registered
Joined
·
4,938 Posts
Runs what ai would discribe as "normal" except for some deceleration poping it has done for very long time. Then after running normal after the 20 or 30 min time frame, pull up to a stop and idle usually drops a 100 or so rpm. Then a little mor time goes by say 5 or 10 min rpm will be low enough engine surges or cycles enough you can hear rods rattle. Eventually engien just cant maintain idle @ 3-400 rpm and quits. Seems to run hotter as rpm decreases but 5hat could be my imagination. It will be hard to start and not roll over fast. Sometimes a reset procedure will get it back to able to idle correctly for a few minutes, but lately not so much. So I hold throttle open for higher rpm or rev at light to keep above idle range.
No it is not what I was thinking it was.
I’m not going to be much help. I’d try calling Lloyd’z, I called them while sorting our two bikes out several years ago and they were forth coming and not unwilling to help. Guy I talked to was quite friendly, knowledgeable etc. I knew more by the time the call ended.

Someone has seen this before. If that call is unproductive try someone else.
edit:
If that fails. Read up on speed density efi. Especially on forums supporting megasquirt diy efi. You might that way come up with a likely sensor that might be failing but not bad when cold on the bench. Map is central to speed density but that doesn’t mean it’s the culprit. I’d first ask around as those calls are free..

A few years ago I asked about a aftermarket map sensor to have on hand and was given this
haven’t needed to put it in so I can’t report anything about it though it says in the listing that it should work.
 
61 - 80 of 80 Posts
Top