Gen 3 surging

[Festus]

Major update!

We pulled the fuel pump today, removed and replaced the fuel pressure regulator. Upon starting, it idled way smoother than it had been. Really really close to being normal. I took it for a spin and the throttle response was instant and the bike felt very smooth, like it should. I tried a few RPM ranges and couldn't get any surging to happen.

I left, Viper Dad took it for a test spin shortly after that and reported the same. Said the bike feels so much smoother than it has been. He was unable to produce any surging but wasn't willing to concede it's fixed until a trip down the Blue Ridge Parkway, which seemed to operate in the zone that causes trouble.

Short term outlook is very promising. That's the smoothest I've felt it run in a couple of years.

Fingers crossed!

I could have sworn someone on here mentioned the fuel regulator and even posted a link to what they looked like, as a generic photo. It was that post that made us look into that but I can't find it in this thread, so whoever said it, Thanks!

[wheatonFJR]

Hmmmmmmmmmmmmm.....

[Dan Cooper]

Major update!

We pulled the fuel pump today, removed and replaced the fuel pressure regulator. Upon starting, it idled way smoother than it had been. Really really close to being normal. I took it for a spin and the throttle response was instant and the bike felt very smooth, like it should. I tried a few RPM ranges and couldn't get any surging to happen.

I left, Viper Dad took it for a test spin shortly after that and reported the same. Said the bike feels so much smoother than it has been. He was unable to produce any surging but wasn't willing to concede it's fixed until a trip down the Blue Ridge Parkway, which seemed to operate in the zone that causes trouble.

Short term outlook is very promising. That's the smoothest I've felt it run in a couple of years.

Fingers crossed!

I could have sworn someone on here mentioned the fuel regulator and even posted a link to what they looked like, as a generic photo. It was that post that made us look into that but I can't find it in this thread, so whoever said it, Thanks!

Okay, do tell. What did you use for a replacement fuel pressure regulator???
I have posted photos and links to a fuel pressure regulator in the past on some discussion thread that I can't remember now.
But someone else may have also done the same thing, so I'm not claiming full credit here.

I thought somewhere along the line you swapped tanks between scooters including the fuel pump and fuel pressure regulator without success.
Do you now think the fuel pressure regulator needs changing in the other scooter also???

dan

[Festus]

Dan, no, the way the events unfolded was :

Swapped tanks, problem went away. What we deciphered from that was the fuel pump was bad. He replaced the fuel pump with an after market pump, that’s just the pump, and the problem was still there.

That lead us down many other paths.

That was until you, or someone else, posted the fact that the fuel pressure regulator was its own thing and could be replaced.

[raYzerman]

Excellent news on getting it fixed!!
We did talk FPR, but full credit is due to Mr. Cooper...... and yes, what was the replacement FPR??

[Festus]

This was the part he used, bought from O’Reilly Auto

https://www.oreillyauto.com/detail/c/st ... 36?q=PR236

[FJRoss]

Where is the fuel pressure regulator?

[Festus]

It’s in the fuel pump assembly.

[Dan Cooper]

This was the part he used, bought from O’Reilly Auto

https://www.oreillyauto.com/detail/c/st ... 36?q=PR236

That's good information. And it's good that one is available locally when you want one on short notice.
Those FPRs are used on a variety of GM and other cars.
The one I purchased was found here. There are many others available from many other sources on the intergoogle machine. Prices range widely.
It cross references to the numbers I found on the OEM FPR from an OEM fuel pump.
https://www.ebay.com/itm/191684542894

The FPR is located on the fuel pump housing, retained under its own separately removeable cap.
The fuel pump must be removed from the tank for access, but the pump housing does not need to be disassembled.




dan

[FJRPittsburgh]

I can't wait for the final testing, but it sounds like you've solved the surging issue. Now Peter can sell it and move on to more dual sport and adventure bikes.

[Powerman]

That part is 57 psi. Spec is 47 psi or 47 psi minimum?

[Toter]

After all this good news, there's always got to be somebody to come shite in your chili!

[extrememarine]

Great News!

Best part is that he still got a new bike out of the deal, and a mostly functional FJR...!!!

[Festus]

We tried to cross reference the part online but it wasn't coming up with much. As mentioned by Dan, $15 on eBay. $80 at AutoZone or Advanced Auto and those were not direct replacement part numbers so we weren't sure on those either. $65 somewhere else. Found this one at O'Reilly, took the original in, nothing cross referenced. Not much detail on the one that we had already picked out. We asked about pressure but their computer didn't show many details at all. Viper Dad said he'd try it.

$35 and it's running.

[Intech]

That is great news, as it removes the suspicion of more chewed wires somewhere.

[FJRoss]

Any chance 57 vs 47 psi is going to blow a hose off? Would be nice to know if the Yamaha spec is a minimum or target. Also, what is the tolerance interval? Troubleshooting says "replace the fuel pump" if it isn't 47.0...

If the pressure is too high, there may be a bit more fuel per pulse. It will be interesting to see if it adversely affects fuel economy. (Is the FJR ECU is smart enough to compensate based on O2 sensor feedback?)
Any improvement in lean condition throttle response at low openings?

[Festus]

Not sure. I wonder if the pressure from the pump contributes to anything in the equation. Time will tell. If there are extra psi, I doubt they are enough to blow a hose.

We'll see. I think he's a bit busy, but next chance he can get out, we'll run up to the parkway and try it out.

[raYzerman]

You certainly won't blow a hose, you'd have to go many times that.. Yep, just ride it, it will be fine... the specification is 43.5 - 56.6 psi at idle. Right in the wheelhouse, no worries. It would have been interesting to know how low the old FPR was actually.
If anyone knows a source of the quick connects, EZ to make a test hose....

[Powerman]

Wasn't trying to piss in anyone's cornflakes about the pressure.
Just a curious question about range.

[LKLD]

So, roughly 3 1/2 years, and you think you’ve got it figured out? Congratulations!! That’s awesome news for Jolene.

However, don’t plan on a tech day at your place.

Seriously, I’m so happy to hear this news…I love that bike. That 2nd gear beats my ‘16 all to hell.

Credit to you both, for not giving up!