VFR Electrical headache

[caseclosed713]

Hello, first time poster here. I'm trying to get to the bottom of my fathers VFR, it's being a real pain in the ass. The bike in question is my dads 1999 VFR. He is the original owner and bought it brand new in 1999. He started having intermittent check engine lights a year or so ago that didn't seem to affect performance. It has 120,000 miles on the clock, and about 3 weeks ago when I came home from work he told me his bike was making what sounded like rod knock. I listened to it, and it sounded horrible. I drained the oil and pulled the oil filter. Tons and tons of tiny metal fragments that looked like glitter poured out of the oil filter. So, I found a 10,000 mile 2001 VFR engine on ebay available locally. Swapped the engine last week and it went well. I found crispy and burnt stator leads while doing the swap. Swapped everything over from his old engine like the throttle bodies, exhaust, etc. I also hardwired the stator leads to the reg/rec leads. Took it out for a test ride, and everything felt great until maybe 10 minutes in. Check engine light comes on, performance seems normal at first. I continue down the road some more and notice the throttle response is getting worse. Trying to rev it up from an idle it would stumble like crazy and take a full second, maybe even 2 seconds to rev up. If I shut the engine off and restarted it, it would run perfectly for 5 minutes then FI light would come on and then the performance would decrease. I repeated this procedure numerous times and it was extremely consistent. I checked the stored codes when home and I'm getting TPS, baro sensor, and MAP sensor codes. These were the codes it would previously throw before the engine swap. I tore the bike down and began trying to diagnose.

 

Here's a list of everything I've checked so far.

 

Tested charging - Peaks around 13.6 volts slightly above idle

Stator leads were hardwired to regulator leads after finding the connectors were melted

Tested TPS, MAP, and Baro sensor - All within ranges listed in manual

Tested voltage from TPS leads - Within normal range

Ground block in wire harness looks brand new

Ground on frame is solid

No damaged or exposed wires anywhere along the harness

Fuses good

ECU connections look good

All vacuum lines in good condition, cleaned out, and going to their proper locations

 

I'm at a total loss of what to do next and very frustrated. Anything I could possibly be missing? 

[Grum]

Good job with the engine swap over.

 

- Check the wiring and connections for main fuse B 30amp, next to your starter relay, its the main power for EFI. It can suffer badly from heat stress, see attached photo.

 

- Recheck the orange earth block located in the wiring loom above your chain guard inspect it very closely. This earth block in notorious for causing the issues you have, especially multiple sensor and fuel pump issues along with random Fi light comming on and complete shutdown.

There will be two wires that actually go to ground. Make sure these have continuity back to the battery negative terminal. Make sure every other wire has good connections to the buss bar and no sign of heat stress. See photo.

 

- Make sure that with Ignition to on you are measuring virtually battery voltage on the Black/White wires at your Fuel Cut relay. This is the main 12v for All your EFI stuff.

 

- Make sure your battery is healthy, fully charged and terminals are clean and tight.

 

Any ECM Active Fault Code will be displayed provided - Sidestand is Down, Ignition On, Kill Switch to run.

 

[DannoXYZ]

What is resistance (ohms) between each chassis ground points and battery negative terminal? 

 

Do you have special break-out box to measure signals at ECU connector?

 

Problem is most likely you have wiring issue as these 3 sensors share common reference-voltage and sensor-ground wires B7 & B2.

 

1. Measure resistance of wire end-to-end between ECU connector terminal B7 & B2 to terminals at each sensor connector

 

2. Measure resistance end-to-end of each signal wire between ECU connector terminal to terminals at each sensor connector

 

3. Measure for shorts between B2 & B7 to any other wire. Resistance should be infinite/no-continuity. Also have assitant wiggle & shake harness while you measure

[JZH]

Which ECU are you using?  IIRC from the infamous "unleash the factory power" thread (😸), they are different between the early bikes and the later ones.

 

Ciao,

 

JZH

[caseclosed713]

Sorry for the late reply, between working 10 hour days and going to school twice a week it's hard to find time to do anything. So anyways, I took another the look at the orange ground block, I took the cap off a checked continuity to ground for each wire. I thought I was onto something when a few wires showed no continuity, but then like Grum said, I realized there was probably a buss bar in the cap. I popped the top off the cap and saw it was two groups of wires that were tied to together. Once I plugged that back in every wire showed continuity to ground and the negative battery terminal. I also pulled every fuse and every connector and found that some had corrosion built up and the contact spot was very tiny. I took this abrasive pad to every fuse and connection I could possibly get to, then used dielectric grease for reassembly. I didn't really find anything I thought was substantial, but I cleaned all the connections up for good measure. I also cleaned all the battery leads and the ground location on the frame. I really examined the wiring harness pretty well this time, but did not locate any areas where the wires might be damaged. I do not have a breakout box so I was unable to perform any of those tests from the ecu. I really felt defeated again, but I put the tank on and took it out. I put about 100 miles on it and I don't want to jinx myself, but the bike ran phenomenal. So much fun to ride and it rips! I also noticed when I was putting the tank on the vent line wasn't laying in there properly and may have been getting pinched the first time I rode it when I was having issues. I'm not sure if that had anything to do with it, but it wasn't helping so I corrected that issue. The bike is back together and I'm handing it off to my dad. We'll see what happens...hopefully all is good. 

 

Thanks everyone for the help, it is much appreciated

 

Here's a pic I took of it today all back together

[Grum]

That ground block is your issue. If your problems come back as before, then the best solution is removing the block and soldering all the wires together.

 

Lesson learnt - The ground block "looked good" but sure as hell didn't Measure Good!

 

Have you had a look at Main Fuse B wiring as suggested?

 

Good luck.

[caseclosed713]

Yes I did check out Main Fuse B. The fuse and connector were corroded which I cleaned up with an abrasive pad, but nothing was burnt up and still looked fine. If he still has the fault codes popping up I will be soldering all of those grounds together. The only reason I didn't the other day is because I need to get myself a new soldering gun. In that pic it looks like an additional ground jumper was added? I assume you ran that to the ground location on the frame?

[Grum]

5 hours ago, caseclosed713 said:

In that pic it looks like an additional ground jumper was added? I assume you ran that to the ground location on the frame?

Not my work, have never done the job!

Provided the existing two proper grounds are ok there is no need to add an additional ground, just a case of properly soldering all wires together.

Once you cut the block off you'll be able to easily identify with a meter the two actual Ground wires, just a continuity check to ground, you might find the two grounds are a slightly heavier gauge wire than the others.