I've got a 2004 VFR. No issues until a few days ago. Then it started stalling while driving normally, at lower RPM's. It runs fine while cold, but a normal temps, the stalling issue kicks in. It also gets progressively harder to restart. For the first time ever, the ABS light started blinking (during normal driving) And yesterday, the FI light came on for the first time ever. So I'm suspecting electrical gremlins. I've only had it running for about a week after sitting idle all winter. Got a new battery. No tuneup yet. The only thing that happened recently is a horrendous downpour the day before, while the bike was outside. That has happened before. But I'm wondering if water is to blame. Either: water in the fuel tank, or just electrical issues. I'd be grateful for any ideas on how to diagnose and fix. thanks Olaf
Hey Olaf. I'm sure you'll have to rule out several things one at a time. I know that at one point my bike started giving me random codes. FI light would indicate speed sensor. Then MAF. Then something else, etc. It turned out to be the typical VFR R/R problem. Follow this link, and specifically look at post #9. As long as you have a multimeter, its a "free" diagnosis. http://vfrworld.com/forums/showthread.php/39277-How-to-fix-common-regulator-Stator-failures
I'd start by drying out the bike thoroughly. It sounds like the problem is pan-electrical, which suggests the charging system is at fault--strange things happen when the voltage drops. As Pliskin mentioned, it's an easy and free diagnosis and well-documented on this site.
I finally got a chance to go out and work on the bike. 1 - its totally dried out now 2 - tried getting error codes off the ECU by jumpering the connector - no codes at all 3 - voltage readings around 13 v - brand new battery Took it for ride again. Runs fine while cold. But once its warm it periodically runs rough and /or cuts right out. Usually while rolling off throttle sharply. But sometimes while running steady at 4k. It ran great for 10 min, then died suddenly. When it dies, its really hard/impossible to restart. Letting it sit for 2 min, allows me to restart - and limp home at 3k stead, feathering the clutch. any suggestions on what to look at next? thanks!
What is the voltage across the battery terminals at idle and 5000rpm? Although the difficult to start symptom suggests it's not a charging system problem.
When the bike is running badly, the next step is to immediately pull the plugs and see if they're getting a good spark. Do you have the shop manual? Check out page 23-2 for helping with diagnosis. Based on the symptoms: intermittent, worsens with operating time, hard to start when warm, FI/ABS lights randomly turning on/off, I'm guessing the problem is the ECU. But this is a diagnosis of exclusion, and you'll have to make sure the ignition, FI, and charging systems are running fine first. If it is the ECU, or any other part, you can find used parts cheaply on ebay.
