Help, fuel pump not priming

[Judge]

Hi guys, first time posting. I have a VFR800 Vtec 2003. It died all of a sudden while out on a normal ride. 
 

Since then it will not start. When turning the ignition everything but the fuel injection lamp lights up as per usual, but the fuel pump does not prime. Attempting to start turns the engine but it doesn’t start. 

 

Manually adding power directly to the fuel pump makes it prime, but the engine will not start.
 

I have checked the fuses and have previously fixed the blue connector’s ground problem. 
 

The engine stop relay clicks but not the fuel cut relay. Swapping the FCR for the high beam relay makes no difference. 

Adding power at the black/white cable on the FCR or at the blue connector makes the fuel pump prime AND makes it possible to start and run the engine.

 

There is continuity between the blue connector and the FCR on the black/white cable, and between those spots and the same cable in the ECM. 
 

I am very bad at this sort of stuff but I have read a lot of threads here and elsewhere and tried a lot of stuff as best I can, but I don’t know how to proceed and would very much appreciate some help. 
 

Any ideas?

[Captain 80s]

I don't have a lot of experience with that generation of VFR, but someone will be along shortly that does, I'm sure.

 

I just wanted to say...   THAT is how you post asking for help on a gremlin.

 

When it happened

What happened

What still works

What has been tried

What's happening now

Using correct terms at the correct times (turn, crank, power, run, on, etc)

Stating that, yes indeed, effort has been made to read and learn

Using paragraphs and punctuation 

 

Good luck, but you won't need it.  There's a lot of very smart, helpful, methodical people on here.  Do exactly what they say, and you will find the issue.

[DannoXYZ]

Don't artificially apply power to anything on harness. Can fry something important like ECU. Use physician's credo of, "Do no harm". Only passive, non-interference, non-destructive testing through measurements only; making no changes to system. Then let the numbers tell you what's wrong.  Do following measurements

 

1. measure resistance between chassis-ground and engine-stop relay's red/org wire. ohms = ???

 

2. measure voltage at engine-stop relay's blk/pnk wire. Volts = ???

[Grum]

Agree with the Captain, good fault description Judge.

 

"Adding power at the black/white cable on the FCR or at the blue connector makes the fuel pump prime AND makes it possible to start and run the engine"

 

You appear to have a loss of EFI power on the Black/White wire, a possible voltage drop situation caused by a bad connection somewhere.

 

Does the Fi not come on at all at switch on?

Are your headlights working normally at switch on?

 

You say you've checked the fuses. Have you had a very close inspection of Main Fuse B 30amp next to your Starter Relay this is your EFI power fuse, the fuse holder wiring and its inline joiner can suffer badly from overheating and high resistance. See attached photo.

 

Clip your voltmeter Black lead onto the battery Negative then the Red lead start at Main Fuse B measure the 12v on the small metal test points on top of the fuse, make sure you measure battery voltage.

Follow the Red/White up to the Blue Connector probe the both sides of the connector verify the voltage. (The wire may change to a Black/Pink at this point).

Follow this to the base of the ESR (engine stop relay).

Does the voltage transfer to the Black/Wire at the ESR?

If yes, continue following the Black/White wire back through the Blue connector again measure it both sides of the Blue connector then all the way to the ECM. 

Check all these voltages with Ignition to On because you are trying to find a bad connection when current is flowing, a voltage drop situation.

 

Hopefully you'll find where the loss of voltage is.

 

[Judge]

12 hours ago, DannoXYZ said:

Don't artificially apply power to anything on harness. Can fry something important like ECU. Use physician's credo of, "Do no harm". Only passive, non-interference, non-destructive testing through measurements only; making no changes to system. Then let the numbers tell you what's wrong.  Do following measurements

 

1. measure resistance between chassis-ground and engine-stop relay's red/org wire. ohms = ???

 

2. measure voltage at engine-stop relay's blk/pnk wire. Volts = ???

I'm sorry, I didn't know you were not supposed to do that. 

 

1: 344 ohms

2: At my latest measurement, it was battery voltage. However some weird stuff happened, see below. 

 

 

11 hours ago, Grum said:

Agree with the Captain, good fault description Judge.

 

"Adding power at the black/white cable on the FCR or at the blue connector makes the fuel pump prime AND makes it possible to start and run the engine"

 

You appear to have a loss of EFI power on the Black/White wire, a possible voltage drop situation caused by a bad connection somewhere.

 

Does the Fi not come on at all at switch on?

Are your headlights working normally at switch on?

 

You say you've checked the fuses. Have you had a very close inspection of Main Fuse B 30amp next to your Starter Relay this is your EFI power fuse, the fuse holder wiring and its inline joiner can suffer badly from overheating and high resistance. See attached photo.

 

Clip your voltmeter Black lead onto the battery Negative then the Red lead start at Main Fuse B measure the 12v on the small metal test points on top of the fuse, make sure you measure battery voltage.

Follow the Red/White up to the Blue Connector probe the both sides of the connector verify the voltage. (The wire may change to a Black/Pink at this point).

Follow this to the base of the ESR (engine stop relay).

Does the voltage transfer to the Black/Wire at the ESR?

If yes, continue following the Black/White wire back through the Blue connector again measure it both sides of the Blue connector then all the way to the ECM. 

Check all these voltages with Ignition to On because you are trying to find a bad connection when current is flowing, a voltage drop situation.

 

Hopefully you'll find where the loss of voltage is.

 

 

I will try to answer your questions in the order you asked them. The Fi (you mean the light on the dash, right?) does not come on at all upon ignition switch on. The headlights work normally. 

 

I thought I had done a pretty good inspection on the 30 amp fuse, but looking at it again now I'm not so sure. The plastics are a bit browned on the backside. I will attempt to attach an image below. 

 

First I should say that when I started today the battery was freshly charged and read 12,5V when measuring at + and - on the battery itself. When I first measured like you instructed on the small metal parts atop the fuse, I got about 10V on one side and 0V on the other. At this time I got 7.5V at the red/white wire at the blue connector, as well as at the black/pink on the other side, and the black/pink at the ESR. 

 

So, I swapped the 30 amp fuse. It then read 11,3V on both sides, which I thought was an improvement. The red/white at the blue connector and the black/pink there as well as at the ESR then also read 11.3V. 

 

At the ESR I get zero V at the black/white cable so I guess the voltage does not transfer there. I tried swapping the relay for the high beam relay (high beam works as normal when ignition is on), but there was no difference. 

 

After having done these tests, I again checked the battery voltage on the battery itself and it was down to 11.2V (I don't know if this is normal drain?). Measuring everything again, I now had the same (i.e. battery voltage) at the 30 amp fuse, both sides, as well as both sides of the blue connector at the red/white // black/pink and at the black/pink at the ESR. But nothing at the black/white at the ESR and, perhaps obviously, nothing at the black/white at the blue connector either.  

 

Having almost no knowledge about this stuff, I don't know what the results of these measurements mean and so I humbly await further instructions. Also I want say I am very grateful that you guys are helping me. 

[Grum]

Ok you've made some progress, that main fuse holder looks heat stressed. Fitting a new fuse has obviously helped but the holder and local wiring should be replaced.

It also appears your ESR is not energizing.

With Ignition to on make sure you measure +12v on the Black wire of the ESR and you have Ground on the Red/Yellow wire, which is provided by the Engine Stop Sensor or Bank Angle Sensor  this sensor can be easily bypassed for testing if you're not getting a Ground.

 

Note - The ESR is a classic Honda example where a Black wire is Positive and the Red/Yellow is Negative/Ground.!!

 

If the voltage and ground for the ESR relay coil are ok then you might want to fit the known good headlight Relay to the ESR position, see how that goes.

Can you follow this on the wiring diagram?

 

And make sure your battery is in a healthy state.

 

Check this and get back to us.

[Judge]

14 minutes ago, Grum said:

Ok you've made some progress, that main fuse holder looks heat stressed. Fitting a new fuse has obviously helped but the holder and local wiring should be replaced.

It also appears your ESR is not energizing.

With Ignition to on make sure you measure 12v on the Black wire of the ESR and you have Ground on the Red/Orange wire, which is privided by the Engine Stop Sensor or Bank Angle Sensor.

And make sure your battery is in a healthy state.

 

Check this and get back to us.

At the ESR the black/pink wire reads battery voltage and the black/white reads 0.02V and the two other ones (black and red/orange) reads 0.42V. 
 

I’m not sure how one would check for that ground, so if you would explain that I would much appreciate it. I’m sorry I am such a beginner at this stuff. If it means checking for continuity between the ground (green) at the BAS and the red/orange at the ESR, then it does not have continuity but rather 200-something ohms. 

 

I have previously tested swapping battery but that made no difference to the main problem (i.e. the fuel pump not priming and the bike not starting).

 

 

[Grum]

40 minutes ago, Judge said:

At the ESR the black/pink wire reads battery voltage and the black/white reads 0.02V and the two other ones (black and red/orange) reads 0.42V. 
 

I’m not sure how one would check for that ground, so if you would explain that I would much appreciate it. I’m sorry I am such a beginner at this stuff. If it means checking for continuity between the ground (green) at the BAS and the red/orange at the ESR, then it does not have continuity but rather 200-something ohms. 

 

I have previously tested swapping battery but that made no difference to the main problem (i.e. the fuel pump not priming and the bike not starting).

 

 

Ok don't worry about the BAS at this stage. The critical issue here is Zero Volts on the Black coil wire of the ESR.

 

Did you do the voltage checks with Ignition to ON?

Have you at any stage of testing switched OFF the Kill Switch? If not and the kill switch IS to RUN do what's suggested below. The kill switch if OFF will kill power to the Black wire for the ESR.

 

Again clip your Black voltmeter lead to the battery Neg.

 

Grab your wiring diagram and follow this Black ESR wire to the Blue Connector. Make sure you measure both sides of the connector for the Black wire do you see 12v on either side?

If not, follow the Black wire up to the Red connector again measure for 12v on both sides of the connector for the Black Wire.

Let's know how you go.

[Judge]

33 minutes ago, Grum said:

Ok don't worry about the BAS at this stage. The critical issue here is Zero Volts on the Black coil wire of the ESR.

 

Did you do the voltage checks with Ignition to ON?

Have you at any stage of testing switched OFF the Kill Switch? If not and the kill switch IS to RUN do what's suggested below. The kill switch if OFF will kill power to the Black wire for the ESR.

 

Again clip your Black voltmeter lead to the battery Neg.

 

Grab your wiring diagram and follow this Black ESR wire to the Blue Connector. Make sure you measure both sides of the connector for the Black wire do you see 12v on either side?

If not, follow the Black wire up to the Red connector again measure for 12v on both sides of the connector for the Black Wire.

Let's know how you go.

And it’s alive! 
 

So, turns out a few things were wrong and I’m not sure what exactly fixed it, but I think it was the 30 amp fuse after all. 
 

Before I read your response I tried putting some dielectric grease on the ESR thinking it might help. After that there was some small sound from something, so I thought there was progress. Then I saw the kill switch was on (which I think my dad did when he was checking some stuff yesterday), so I flicked it off. Then the fuel pump primed, but the bike did not start up and after turning the ignition off and on again it did not prime again. That’s when my dad realised that the jumper cables to the battery (we were using a separate battery because my other one got low voltage from all the testing) were weirdly hot, and he thought it was because they were too small. So we changed to larger ones and after that the pump primed and the bike started. 
 

So I guess if the kill switch would have been off and the battery connected normally, the bike would have started either after replacing the faulty 30 amp fuse and/or greasing the ESR, but probably the former. 
 

Huge thanks for all you guys’ help, especially you Grum. If I could bother you with one last question it would be if you could expand on what you recommend me doing with the heat affected 30 amp fuse holder/wiring. Can I just order/buy a new one somewhere and if so is it easy to install? 
 

Thanks again!

[Grum]

41 minutes ago, Judge said:

And it’s alive! 
 

So, turns out a few things were wrong and I’m not sure what exactly fixed it, but I think it was the 30 amp fuse after all. 
 

Before I read your response I tried putting some dielectric grease on the ESR thinking it might help. After that there was some small sound from something, so I thought there was progress. Then I saw the kill switch was on (which I think my dad did when he was checking some stuff yesterday), so I flicked it off. Then the fuel pump primed, but the bike did not start up and after turning the ignition off and on again it did not prime again. That’s when my dad realised that the jumper cables to the battery (we were using a separate battery because my other one got low voltage from all the testing) were weirdly hot, and he thought it was because they were too small. So we changed to larger ones and after that the pump primed and the bike started. 
 

So I guess if the kill switch would have been off and the battery connected normally, the bike would have started either after replacing the faulty 30 amp fuse and/or greasing the ESR, but probably the former. 
 

Huge thanks for all you guys’ help, especially you Grum. If I could bother you with one last question it would be if you could expand on what you recommend me doing with the heat affected 30 amp fuse holder/wiring. Can I just order/buy a new one somewhere and if so is it easy to install? 
 

Thanks again!

 

Well thats good news and glad it appears to be all to do with that 30amp Main Fuse and its wiring.

 

See attached replacement for the fuse. Any good Auto parts store should have something similar, make sure its at least 30amp rated.

It will require some good crimping or solder and sleeving to the bikes original wiring. Best to get rid of the original, inline splice as well its not really needed. If you're not up to the task of fitting it, any Auto Electrician should be able to fit it for you.

 

Suggest using OxGard instead of dielectric grease. With the new fuse holder in place some OxGard applied to the fuse legs would be good.

 

Also I think you should fully charge your battery and have it load tested at any good Automotive Parts and Accessories Store. Your battery voltages do seem a little suspect.

Good luck.