no spark from new coil pack??

jimmyd87

Getting no spark on the vfr even with new coil packs. I have 12v coming down to the 12v side of each pack, the lead is on the plug and I have the plug grounded to the frame, the signal is flashing on the meter(12v side) as i'm cranking the engine with the start button but still nothing. Changed plugs also, tried new and old, nada :mad:

Anyone have any ideas?
Thanks in advance

uncle betty

jimmyd87 wrote: »

Getting no spark on the vfr even with new coil packs. I have 12v coming down to the 12v side of each pack, the lead is on the plug and I have the plug grounded to the frame, the signal is flashing on the meter(12v side) as i'm cranking the engine with the start button but still nothing. Changed plugs also, tried new and old, nada :mad:

Anyone have any ideas?
Thanks in advance

Obviously the engine stop button is set to RUN, and the sidestand is up - many's a time I've screwed it up..

Did you have the covers off for any reason ? Just thinking of the pulse generators - maybe they're not generating a signal ?

Will try to find a wiring diagram online, and will get back to you.

What year is it ? And is it 750 or 400 ?

uncle betty

OK mate, I found a manual online for a vfr750f, and I'd guess there won't be much if any difference in the wiring between different years. Hopefully not, anyway.

Here's the way I'd go about it.

1. Check the connector blocks - one is from the pulse generators to the black box, with four wires - yellow/white&yellow/yellow/white&blue.

The second one is from the sidestand switch, with three wires - green&white/yellow&blue/green.

Make sure they're all good and tight, no sign of corrosion or burning.

2. Make sure your battery is well-charged. Very important.

3. You already got 12v at the primary side of the coils, but make sure you have 12v going into the box, on the black&white, because the diagram shows the feed splitting to the coils and to the box.

Also go back with the red probe of the meter to the fuse, ignition switch and main fuse and see if the voltage is the same at all points along. It should be.

4. Check the pulse generators are ok. Disconnect the y/w&y/y/w&b. Set the meter to Resistance, and go between y/w&y wires on the engine side of the plug.

Should get 400-500 Ohms. And should get more or less the same reading for y/w&b.

5. Check the neutral switch wire for no obvious damage. Use the meter to make sure that there is continuity between the light green wire, and ground, when you're in neutral only. The meter will either have a beep function, or just use the Resistance setting and look for a reading of 0 ohms.

All other gears, there should be no continuity/no beep.

6. Check the sidestand switch. With the sidestand up, there should be continuity/beep/zero resistance between green&white and the green ground wire.

With the sidestand down, no continuity/no beep/infinite resistance.

---

If I can help I will, so ask away. Hope that gets you a result.

jimmyd87

Many thanks for the informative reply u. betty, shortly after I posted I got a manual online and tested the resistance of the wiring coming out of the crank casing as per the trouble shooting guide, where I found an open circuit in the pulse gen. (w&blu/blu) you mentioned so a replacement is the next port of call.
There has been no major problem with this bike ever and no work other than the necessary maintenance.

Failing this, what else could be contributing to this problem considering there's new coils packs, battery, plugs, HT leads and caps?

Having googled this problem it seems that it wasnt an usual from vfr's of the time either!

Its a 1992 vfr400r also.

Thanks again:D

uncle betty

jimmyd87 wrote: »

Many thanks for the informative reply u. betty, shortly after I posted I got a manual online and tested the resistance of the wiring coming out of the crank casing as per the trouble shooting guide, where I found an open circuit in the pulse gen. (w&blu/blu) you mentioned so a replacement is the next port of call.
There has been no major problem with this bike ever and no work other than the necessary maintenance.

Failing this, what else could be contributing to this problem considering there's new coils packs, battery, plugs, HT leads and caps?

Having googled this problem it seems that it wasnt an usual from vfr's of the time either!

Its a 1992 vfr400r also.

Thanks again:D

No prob, delighted to help. Though it looks like I was wrong about the wire colours being the same across models - sorry for the confusion

If that pulse gen. coil is gone open, that's definitely a problem. Not a chance of a spark going to that coil. Though on the other hand, if the W/Y & Y one is reading correctly at 450 to 550 Ohms, you'd imagine that you'd have a spark off it's coil.

What else could it be apart from a bad/open connection ? I mentioned the clutch/sidestand/neutral switches, but I don't even know if they are part of the circuit on your bike ? I found a 400 manual here http://www.akhara.com/nc30/nc30manuals/VFR400R_Shop_Manual/VFR400R_C15.pdf which has none of that ''safety'' crap.

The black box itself could be shot. No chance of a friend having one that you can just plug in and see ?

Also, and this more theoretical - you mentioned a new battery. Were there problems with the old one, eg all the electrolyte being boiled off ? They mention here http://www.bikersoracle.com/vfr/forum/archive/index.php?t-65804.html that a bad regulator can also in theory screw up your black box if there's too much voltage.

They're a known problem on Honda, I think.

Let us know how you get on, be interested to see what occurs. Hopefully the new pulse gen. unit does the job. All the best.

jimmyd87

Right my mistake, the pulse gens are ok, got a few dodgy readings but i'm happy theres continuity. (400 ohms ish)

The cdi was toast due to water damage, it had been turned up side down when the tyga fairing kit was being put onto the bike :mad:

So now I have got another cdi from second hand parts dealer and a seemingly ok pulse gens, where do I go from here?

Still no spark tall tall!

uncle betty

jimmyd87 wrote: »

Right my mistake, the pulse gens are ok, got a few dodgy readings but i'm happy theres continuity. (400 ohms ish)

The cdi was toast due to water damage, it had been turned up side down when the tyga fairing kit was being put onto the bike :mad:

So now I have got another cdi from second hand parts dealer and a seemingly ok pulse gens, where do I go from here?

Still no spark tall tall!

Hi jimmyd, sorry to hear you´re having no success. Just a quick question for now - are you sure the cdi you got from the dealer is working ? That´s why I mentioned earlier to get a loan of one from a friend, ie one that you know for sure is working.

See where you said in the first post that you have 12v coming down each side to the pack ? Do you also have 12v going into the cdi itself ? In the wiring diagram I´m looking at here http://www.akhara.com/nc30/nc30manuals/VFR400R_Shop_Manual/VFR400R_C15.pdf the feed to both coils is the same feed to the cdi itself - it´s the black/white wires. You should have 12v into the cdi on a black/white as well.

If you haven´t done all of this already, I´d still double-check all connections and plugs, and make sure your battery is strong. I posted on another thread a few months about how I test a battery, it´ll be easy to find.

Am out of the country on holidays at the moment, back on Monday. If I think of anything I´ll post it in the meantime.

ps If I´m still using the wrong wiring diagram will you link the right one for me please, so we´ll be reading off the same page, as they say.

Good luck.

jimmyd87

Ok, there is blk/whi wires to the front and rear coil packs which are switched 12v, then there is blu/yel and yel/blu to the front and rear coil packs also, these are coming from the cdi and I'm guessing that their providing the pulse to the coil for the high tension side?

The manual states that if go between either of these blu/yel wires on either coil pack and ground I should get the batt. voltage once I turn the ignition on. Not happening.
Once I start to crank it over I should get the peak voltage of about 140v, again, not happening.
So it looks like the cdi just isn't spitting anything out?

The pulse gens are giving me about 400ish ohms so there ok according to the manual.
The plugs, leads, coils and batt. are new and the cdi was got from a parts dealer.
I've checked all the connections, plugs and earths etc all over the bike and I'm happy its not something stupid at this stage.

Is their anything else I should be having a look at before buying a second (new) cdi to try and rectify this problem?

Thanks again!

uncle betty

jimmyd87 wrote: »

Ok, there is blk/whi wires to the front and rear coil packs which are switched 12v, then there is blu/yel and yel/blu to the front and rear coil packs also, these are coming from the cdi and I'm guessing that their providing the pulse to the coil for the high tension side?

The manual states that if go between either of these blu/yel wires on either coil pack and ground I should get the batt. voltage once I turn the ignition on. Not happening.
Once I start to crank it over I should get the peak voltage of about 140v, again, not happening.
So it looks like the cdi just isn't spitting anything out?

The pulse gens are giving me about 400ish ohms so there ok according to the manual.
The plugs, leads, coils and batt. are new and the cdi was got from a parts dealer.
I've checked all the connections, plugs and earths etc all over the bike and I'm happy its not something stupid at this stage.

Is their anything else I should be having a look at before buying a second (new) cdi to try and rectify this problem?

Thanks again!

Well jimmy,

Just put your meter on the black/white wires at three points, and tell me what voltage you get at each -

1. From ground to the black/white on first coil.
2. From ground to the black/white on second coil.
3. From ground to the black/white where it goes into the cdi.

You need to do all three.

It may well be the cdi is shot, but don't spend the bucks until you have to.

jimmyd87

Well sir,

1. 12v
2. 12v
3. 12v

There's a blk/whi wire going from the out-going side of the stop switch to the front and rear coil packs and then to the cdi, which I have 12v on.

What I'm missing is the out-going signals from the cdi to the yel/blu wires on the second terminal of each pack allowing them to fire as per various diagrams I've looked at. These should have 12v once the key is turned to start with and then peak voltage should appear when the bike is being cranked, but that aint happening!

All roads point to the cdi again at this point, but knowing my luck it wont be that simple!!

uncle betty

jimmyd87 wrote: »

Well sir,

1. 12v
2. 12v
3. 12v

There's a blk/whi wire going from the out-going side of the stop switch to the front and rear coil packs and then to the cdi, which I have 12v on.

What I'm missing is the out-going signals from the cdi to the yel/blu wires on the second terminal of each pack allowing them to fire as per various diagrams I've looked at. These should have 12v once the key is turned to start with and then peak voltage should appear when the bike is being cranked, but that aint happening!

All roads point to the cdi again at this point, but knowing my luck it wont be that simple!!

Hard to see what else it could be, going by the diagrams anyway. If you have power in, nothing coming out of the same plug connector, and you've changed everything else...

A pity there's no-one could give you a loan of a known working unit to plug in for a minute.

Sorry I don't know what else to suggest. Good luck with it anyway, hope you get her going soon.