FJRiders.com

FJRoss wrote: ↑Mon Jan 18, 2021 8:23 pm You already knew that the fuel pump relay works at least some of the time - otherwise it would never run at all.
The diagnostic test identifies which is the right relay so that's good.

• Yes. But my thoughts are that relays often have inconsistent contacts.. Intermittent.

Relay might be an issue or wiring/connections to or from the relay. This was the front end that got Bambied a number of years ago.
Flakey fuel pump relay (or fuel pump) might do this. Check the pressure on the fuel rail.

• How does one check pressure on fuel rail? Haven't wrapped my head around that axle yet..

You might want to try some of the wire wiggling/voltage measuring that 1911 did when he had issues. Might want to move that harness around some while running the engine.

• I have wiggled every wire on the FI system, no joy yet.. But will keep wiggling..

Still can't see how it could be timing if it runs well at least some of the time. That audio clip sounded like a pretty sick motor but if it skipped a tooth, it wouldn't run right any time.

• I think I agree with this. I slipped a cam timing tooth on the Kz1300 back in the day, it was a consistent, not intermittent problem.

Did you compare the temperatures of the four pipes where they come out of the engine using your fancy new IR camera or a temperature probe? Or use a contact thermocouple which would be more accurate. Will quickly tell you if all are the same. No point in comparing left vs right at the exhaust pipes - system is 4 into 1 into 2.

• No, I have not.

I concur with Ionbeam - no way a slightly flakey TPS could do this. Not unless it was FUBAR.

• Escpecially since I selected the best TPS of 4 in inventory.. Will post data later in this thread..

raYzerman wrote: ↑Mon Jan 18, 2021 9:19 pm About valve timing being off... it may run just fine until 4-5000 then not develop horsepower after that, or at least very slowly. Usually no popping though, and idle may hang up rather high (2000) before settling down. I'd guess retarded a tooth in that case. Can't speak for advanced, usually not the case.

• I've been fighting this issue for at least 2 years.. that's the good thing about having a blog where documentation is king... it ran great after last valve adjustment... then this again, like has happened before..

So let's ask, if timing was OK last time you had the valve cover off, did it run OK then? Was there any time since then the CCT was backed off and chain not zip tied at the crankshaft? Unfortunately the only way to verify valve timing is to pull the valve cover (coolant drain and all that jazz).
Have you checked right timing cover has not pinched the ignition pickup wiring that goes up the front side? That will cause some of the crap you're seeing. Pull the clips and ensure the harness is not trapped, particularly at the top of the timing cover.

• Yes. Last valve adjustment. https://candybuttorg.ipage.com/cba/node/679

and she ran great until now. But at Tyler's Yosemite run, it actually quit running *at all* at park entrance. After a bit, she started, and got back to base camp.. fiddled around a bit, thought it was fixed, took a ride with PanMan on a goat trail, and it was horrible...

ionbeam wrote: ↑Mon Jan 18, 2021 2:55 pm One small thing to contribute -- the TPS if just fine with any of the readings you got, statically on the bench. The TPS receives a zero and +5 volt reference voltage from the ECU. Note that zero and ground are not necessarily the same because it is a reference voltage and not a utility voltage like lighting or instruments. The wiper of the TPS will return a 0.7 to 5 VDC to the ECU that is proportional to the throttle position. The ECU does an A/D conversion, then does some math on the voltage to convert the voltage to % of throttle opening. When you see 15 to 17 it indicates the ECU thinks the throttle is 15% to 17% open which it needs in order to idle (the 0.7 volts equals 15% and ≈ 4.8 volts equals 100%). The bottom number will change with idle speed adjuster screw in addition to the turning calibration of the TPS body so there is no real, absolute number. If you want to play, try the idle speed adjuster, this is why you can't get the numbers you want (but don't really need anyway). Turn down the idle speed adjuster and the TPS percentages will drop down. A reading of 101 to 104 indicates the ECU thinks the throttle is 101% to 104% open. The ECU will clip anything over 100%. The range between the bottom number and the upper number is fixed, you can't make the difference larger of smaller, you can only shift the whole thing up and down. Ideally, you would set the idle speed then adjust the TPS. But, as soon as you do a TB sync and then move the idle speed the TPS will be off again. Lots of words to say don't sweat a few % error of the TPS reading.

The TPS is one of several things the ECU looks at to determine the FI shot and ignition timing. As long as the TPS voltage is stable and tracks the throttle the TPS is a minor player in the FI/ignition mapping. If the TPS is non-linear by having drop-outs which exceeds some programmed limit the ECU will react by going into the fuel-cutoff routine. As soon as the TPS passes the damaged portion of the resistor and returns to a normal reading the ECU will have a slight pause (to be sure you really mean the throttle increase) the jumps the FI/timing map back up again. This is the same as abruptly chopping off the throttle then whacking it wide open. It's a rough ride when that happens but it is transient. Importantly, it will happen at the same exact throttle opening, regardless of gear once the engine is warmed up. This is one of the best indications of a TPS failure. My TPS had two drop-out points, one just off idle at around 1,700 RPM and again around 3,000 RPM where it predictably demonstrated the TPS failure.

Given where DCarver lives it isn't unlikely that the sock on the fuel pickup may be clogged. However, this would be more likely to show up as weak performance as the RPMs climb. Usually the fuel pump works yes or no but not maybe or not at a certain RPM unless there is a voltage glitch to the pump motor. The ECU monitors the voltage to the pump and the voltage can statically be seen via diAG. Since Dave has a second tank and the swap is simple it could be done just to verify the pump isn't the problem.

IMO (which may not be worth much) a hard failure at predictable engine speed points to an electrical problem. The only exception may be a carbureted engine from the 80s & 90s that had an emissions bump at 4k RPM as the carb transistion from the idle jets to the main jets.

Given where DCarver lives it isn't unlikely that the sock on the fuel pickup may be clogged. However, this would be more likely to show up as weak performance as the RPMs climb. Usually the fuel pump works yes or no but not maybe or not at a certain RPM unless there is a voltage glitch to the pump motor. The ECU monitors the voltage to the pump and the voltage can statically be seen via diAG. Since Dave has a second tank and the swap is simple it could be done just to verify the pump isn't the problem.

dcarver wrote: ↑Tue Jan 19, 2021 12:42 am

...Since Dave has a second tank...

...BTW, 'Dave's not here man!'

raYzerman wrote: ↑Tue Jan 19, 2021 10:00 am FYI, you can get new generic pumps only, for cheap. Buy two if you like. I have used Honda specific ones, they work fine. Pumps are really simple inside, you may just have clogged up filtering.........

raYzerman wrote: ↑Tue Jan 19, 2021 10:46 am I usually pick something that looks "branded" but they are mostly a motor housing with an impeller at one end, inlet on the other, fuel flows around/through the motor keeping it cool. Constantly circulating fuel (for cooling) in some (Honda or Gen1 FJR e.g.), Gen2/3 recirc is likely internal in the tank. There are only a couple of different kinds used by the OEM's, e.g., specific to Yamaha, specific to Honda, but could be shared design with Kawi or Suzi. Keep the entire big plastic housing/sender and replace just the pump and inlet screen that usually comes with it. Sender is on its own circuit, thus two plugs under the tank. I have not replaced an FJR pump, might be a thread somewhere where somebody did forensics, I know some did on Gen1's where tanks were rusty, way back.

ionbeam wrote: ↑Tue Jan 19, 2021 11:25 am Didn't you remove the CA fuel evaporative canister from KrZy8? I seem to remember some air intake plumbing that was left uncapped. This leads me to ask how the throttle body intake #3 and #4 plumbing from the evaporative canister was capped.

• Yes. After Bambi strike, dealer ordered incorrect lower cowl.. so eval was eliminated. Unfortunately, tech didn't plug lines, engine ingested unfiltered particulates and thus a replacement engine. Those hoses are now capped.

If you have a fuel pressure gauge, the fuel should be delivered at 46 psi. I checked the fuel pressure on my Gen I while riding when troubleshooting a driveability problem. It was a tough plumbing effort to get the gauge connected. The Gen I used a different pressure regulation system than the Gen II, the Gen II fuel pressure is straight out of the pump and through the output fuel filter.

• Ray has offered up a fuel pump testing kit... and should have correct adapter. When it arrives, will test both FJR's to obtain data.

fjray wrote: ↑Tue Jan 19, 2021 11:29 am I'm pretty sure I have a generic pump on the shelf and this weekend I'm supposed to get a FJR parts pile that should have a tank with a pump in it. Either one or both are yours if you want them.

• Awesome! Thank You Ray.

dcarver wrote: ↑Thu Jan 21, 2021 3:30 pm 15 miles later still running GREAT. New Ivan ECU is amazing.

wheatonFJR wrote: ↑Thu Jan 21, 2021 4:35 pm

dcarver wrote: ↑Thu Jan 21, 2021 3:30 pm 15 miles later still running GREAT. New Ivan ECU is amazing.

So, it wasn’t the fuel pump thingie?

It’s running good now?