2000 VFR Fuel Injection Failure

[SkyAmI]

During a long tour last year, I had my FI system shut down for no discernable reason.

Failure description:cruise at steady speed, motor stops as though I turned off the engine run switch - FI light comes on - turn key off, then back on, and it will re-start. This happened 4 or 5 times, then when it happened again, it would not re-start. When this happens, the fuel pump won't spin up. Shorting the diagnostic connector will show a diagnostic code of 15 (one long, 5 short), that indicates the #4 injector is bad.

I had to leave the bike a the closest dealership where they replaced all 4 injectors, plus the injector wiring harness (big $$). I picked up the bike later and rode it 3 hours home, plus put a few more miles on it over the next couple of weeks. It failed again in the same way, so I replaced the Voltage regulator/rectifier per a note in one of these on-line forums, but it failed again.

I took it in to my local dealer. They looked it over, replaced the fuel filter, checked fuel pressure, tested the wiring from the injector harness to the FI controller (didn't find anything), then swapped the #3 with the #4 injector. Once that was done, the controller didn't throw any more codes (no failures after the shop folks put 1.5 hrs on it), so we thought maybe they found a bad connection that got fixed while mucking around with the injectors. Took it home, but it failed again after about 45 minutes. This should eliminate the injectors as the failing item since it showed #4 as bad before, and it still shows #4 as bad, even after swapping #3 with #4.

I then replaced the FI controller based on assurance from the shop, and from Honda factory folks that this absolutely was the fix... No good... failed again after about 15 minutes.

So - all of the major items have been replaced. Any ideas on what to look at next?

[reg71]

dude, what a PIA you have had! That really sounds like a short to me. I think I'd just start by tearing off all the plastics and looking at the wires then check and see if voltages are where they should be. I feel your pain on that one.

[murdrcycle]

I had a similar problem. It happened to me twice. Mine was caused by too much heat combined with too lean of a mixture. I changed to Engine Ice and quit filling up with Super Unleaded (anything higher than 87 leans it out).

[reg71]

didn't think about that. I remember reading that when I first got my VFR and I switched to using 87 octane. Mine wasn't dying, but it wasn't running as well as it does on regular unleaded.