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Festus wrote: ↑Sun Nov 19, 2023 1:22 pm There's a FB group for FJR mechanics. I posted about this issue on there. Someone posted that we need to swap the Mass Air Flow Sensors. I questioned where they were, since the manual didn't list anything as Mass Air Flow Sensors. Silly me for asking a question, the person that said that responded "Then don't listen to me".

I thought it was an honest question, but I guess not, but none the less, it's the 2 sensors on top of the throttle bodies. Same part number for both. Viper Dad finally swapped them a week ago and it changed nothing.

I guess the last step is swapping the ECU? Any harm in doing that between our bikes? Just unplug and swap?

Shouldn't be any issue.

Did you ever try swapping fuel tanks (with pump assembly and lid for possible venting issues). What about complete fuel rail with injectors? Either of these things would be relatively quick and easy to do.
This has been going on so long that I can't remember what has been actually tried vs just discussed.

Yup, tanks swapped, injectors swapped, fuel rail changed out.

Festus wrote: ↑Sun Nov 19, 2023 2:11 pm Yup, tanks swapped, injectors swapped, fuel rail changed out.

You guys don't just pin that throttle and go?

When you pin the throttle, it goes. That's the problem.

At this point, he's replaced every sensor that has to do with acceleration, gone through everything everyone on this forum has said, except for the ECU, I think. There aren't any parts left to replace, unless it's spark related.

We've swapped coils, he's changed plugs. Unless it's upstream from the coil, or in the ECU, I'm at a loss, as is most everyone else who's looked at it. Bob worked on it for a while and couldn't resolve it at the time. Blind Squirrel and Powerman have both fiddled with it. Probably some other people as well.

I don't know what else to try other than swapping out the ECU.

Swap bikes. The ultimate parts cannon.

I watched people fiddle with it and that didn't even seem to help!

I think I would go back to the hidden, mouse induced damage to the wiring harness. Very difficult to find indeed. But, may be the only way. Complete disassembly, inspection, and reassembly. I would have given up years ago, and kicked that bitch to the curb. No mechanical device is worth that amount of frustration. But then, I'm impatient, and would be so jaded towards it, that I would just want it gone.

I know it seems like a lot but I swear every time we talk about digging into it deeper, Viper Dad says we should just ride, it’s fine. I mean we only try something once every 6 months

I have some surging on mine around 3800rpm. I just ride the dang thing. It gives me joy and owes me nothing.

swap the ecu's.

If that isn't it, it's wire damage from rodents from way back at the beginning...

Just get it fugured out before we ride the Cherohala next spring...

extrememarine wrote: ↑Sun Nov 19, 2023 9:00 pm swap the ecu's.

If that isn't it, it's wire damage from rodents from way back at the beginning...

Just get it fugured out before we ride the Cherohala next spring...

It’s not an issue, it doesn’t happen bouncing off the rev limiter

Is the issue apparent in Sport mode AND Touring mode?

raYzerman wrote: ↑Sun Nov 19, 2023 11:44 pm Is the issue apparent in Sport mode AND Touring mode?

Not their bike...but I will check that out on my 13 next time I'm out...

FJRPittsburgh wrote: ↑Sun Nov 19, 2023 3:20 pm I watched people fiddle with it and that didn't even seem to help!

You know, never thought about trying that. But, of course it would be too heavy for my weak ass body. I bet Lumberg could though!

Toter wrote: ↑Sun Nov 19, 2023 8:02 pm I think I would go back to the hidden, mouse induced damage to the wiring harness. Very difficult to find indeed. But, may be the only way. Complete disassembly, inspection, and reassembly. I would have given up years ago, and kicked that bitch to the curb. No mechanical device is worth that amount of frustration. But then, I'm impatient, and would be so jaded towards it, that I would just want it gone.

I was unaware of the resurrection you performed on Jolene, until I recently read through that thread. I now understand the commitment to fixing this problem. After all she's been through, just doesn't seem fair to be fighting a surging issue for so long.

I thought "Who knows about ECU's"? Ivan.

I called him and spoke with him for about 10-15 minutes. Very helpful man. He ruled out the ECU, all but completely. We talked through a couple of things, things we had changed out already.

He was insistent that it's pretty logical. Said the oxygen sensor on the exhaust wouldn't cause it. That would kick a code if it was a problem, which is has not. He did suggest that the aftermarket fuel pump would be something to look at, stating that it's known to produce incorrect fuel pressure. Gave me some methods to try to isolate whether it's fuel or spark related. We'll try those, eventually. Viper Dad just got heated gear so the chance of saying "let's work on the bike since it's cold outside" and hearing back "Screw it, let's ride" has just increased greatly.

Ivan did say that the ECU has coil drivers on it and it's possible one of those is bad but not too likely because when they do go bad, they tend to cease all spark, if I remember what he said correctly. He was pretty confident that swapping out the ECU's was a complete waste of time.

I think part of what he said to do was to get it idling and then start doing various things to see if those things had any impact on it while it was running on the center stand.

So... Continue shooting ducks.

(Pumps a shotgun at the sky)

I think his advice was really solid on what to do. We'll see. Maybe some time in the next couple of months, we'll take a stab at it.

Isn't fuel pump ruled out already? You mentioned that you had swapped tanks... (same with fuel rail and injectors).

FJRoss wrote: ↑Mon Dec 04, 2023 7:56 pm Isn't fuel pump ruled out already? You mentioned that you had swapped tanks... (same with fuel rail and injectors).

I thought so. His suggested testing should determine if it's fuel or spark related. He was over my head on a lot of what he was saying so I'm trying to piece together what he said to do. He was kind enough to talk to me for free and I was respectful for his time and I didn't want to keep asking him questions. I think he gave me enough to determine if it's fuel or spark. Once we know that much, we'll move to the next steps. Knowing Viper Dad, it might be March before we look at it.

He knew exactly how the ECU acted on what situations and what settings/limits were being called for when. His knowledge of all of that let him very quickly rule out a number of things.