well, just when you think every things ok, it all goes wrong… been out on vf tonight, got three mile then…phut phut phut…all goes dead…lukily theres still some good sammaritans out there,[:)] and the vf came home in the back of a local plasterers van (very gratefull).any how, on inspection ive got decent sparks to all plugs ,but no petrol to any cylinder, although the tanks full.[:(]. has anyone got any ideas (fule pump or relay maybe[?])…think ill join aa tomorrow…
quote:
Originally posted by vf petewell, just when you think every things ok, it all goes wrong… been out on vf tonight, got three mile then…phut phut phut…all goes dead…lukily theres still some good sammaritans out there,[:)] and the vf came home in the back of a local plasterers van (very gratefull).any how, on inspection ive got decent sparks to all plugs ,but no petrol to any cylinder, although the tanks full.[:(]. has anyone got any ideas (fule pump or relay maybe[?])…think ill join aa tomorrow…
Bad luck Pete…disconnect the fuel pump relay and put a jumper lead in the block…Ignition on and see if any fuel is pumped out… ( into a suitable container of course)
There’s a figure in the manwal that tells you what the flow rate should be. If that’s O.K. the problem is further on…
Tim.
thanks tim, tried that and loads of fuel pumped out, put the plugs back in and re conected the fuel pump relay , fired up first go. It concerns me that the bike is now running, but i havent fixed any thing…whenever i set off anywhere ill be thinking its going to happen again…i wonder,as a “get me home” if you could insert the jumper wire and ride the bike, or would it flood the carbs/cylinders…ive read somewhere on here of someone having similar problem, i think he carried a spare piece of petrol pipe and by passed the pump making it gravity feed, cant remember what the out come was.will have to have a look through the topics.
Hi Pete, I have just had exactly the same problem, full tank and no fuel to carbs, did some checks with the meter and suspected the fuel pump relay I used a jumper wire the same as you and the pump worked, so bought I a new relay from honda (approx £60) it did’nt work, turned out the fault was intermittent, after checking all the wiring for resistence (fine) went through regulator/recifier/stop switch/fuse box/coils/earths and finally the CDI, it then burst back into life after trying another CDI on, this was after eliminating all the previous by checking with the meter, because it was intermittent I felt like a dog chasing its tail going through the wiring three times over, the blue wire goes from the CDI to the coils via the fuel pump relay so since changing the CDI the problem seems to have disappeared…
I’m not sure if this could be bypassed as the ignition system was working fine, maybe someone else knows.
The CDI’s are a pain on older bikes as the capacitors inside have a life of 10 - 15 years and the transistors wear out and you can blow a zenor diode by jumping off another battery.
Have you got a spare to try? give us a bell if you dont get it sorted I’ll take mine off and fetch them up to try,
Phil.
Sounds like I have the same sort of problem. Will chase up when the top end oiling kit is fitted and the carbs are back on.
hi phil, thanks for the info, that sounds like one hell of a lot of checking youve done. im actually running on a set of cdi’s i bought off ebay a while back, i tried them because i had a misfire and rough idle,but this turned out to be a carb problem. anyhow ive still got my originals, so ill swap them over…when ive a bit of spare time im gonna check the the wireing/conections ect.(electrical faults, especialy intermittent ones arnt my strong point).ill give you a bell if i get stuck.
p.s. hi humph hope you get things sorted…
pete.
hi again phil, just looked on the sabmag site and found a perfect discription of what hapened to my bike…bike looses power, followed shortley by complete loss of power (main suspect,the cdi which powers the fule pump)link to site. http://www.sabmag.org/oilmods.htm .then click (maintenance tips and modifications,then click spark box repair)…the article is mainly about the cdi’s, but touches on some side effects they cause when they start to fail…
pete.
This is a problem caused by Honda’s obsession with “safety” and an over-engineered solution that has come to it’s natural expiry date…
Honda knew that the VF range needed a fuel pump because of the layout of the bikes (tank not high enough above the carbs basically).
They got all paranoid about fuel spillages with a bike on it’s side, floats stuck open and the pump just pumping away… (what happens on a gravity feed bike…? It just leaks…!)
So they built a circuit into the pump relay that “rectifies” the power pulses from the ignition unit (1-4 on FE models). This means that the pump will only pump fuel with the ignition unit producing pulses (engine running).
You may have read up on how to prime the VF carbs by switching the kill switch off/on repeatedly…?? Works for the pump, but the ignition units are OLD and this kind of treatment is NOT what old electronics need (true about old capacitors & transistors, we need to be kind to these old circuits…)
So… What happens…? Well, the fuel pump gets old and sticky and draws more current than it really should… Not dangerous, just an old part showing it’s age…
However, the relay is old too and decides it’s going to give up the ghost… Result - no fuel… Gravity feed is a partial fix but often not good enough to sustain high speed riding…
Hot-wire link across fuel relay connector will revive the pump… but now it’s on ALL THE TIME… as long as the main switch is on, the fuel pump is on… Not necessarily a good thing…
What did I do…?
I fitted a “normal” £2.99 single pole relay into the wiring instead of Honda’s £60 item…
It’s mounted in the same place as the original fuel pump relay and uses some of the original wiring… It switches the pump on when the bike’s kill switch is in the “on” position and off, when it’s “off…”
Here’s what I did…
The harness wrapping on the rear of my FE was a bit tatty (to say the least). I unwrapped it up to where it joins the main harness under the seat…
I pulled the 3 pins out of the fuel pump relay connector. This gave me:
Blue Wire - Power pulses from 1-4 Ign Unit
White Wire - Power out to Fuel Pump
Black Wire - +12V from Fuse #5 (Ignition)
I reterminated the White and Black wires with 6.3 mm spade terminals (to suit the relay I was using). These connect to the relay switch - the black is the power in, the white is the power out.
Next; I exposed the splice where the blue wire joins the ignition wiring… I cut the blue wire off and re-insulated the splice…
Then; I dug into my box of wiring junk… found a nice green wire, terminated it with a 6.3 mm spade at the relay end (coil earth) and a 6 mm ring terminal at the other end… I slipped the ring terminal under the 6 mm bolt that holds the breather bottle clamp in place…
Finally; digging into the wiring to the ignition units (my FE has 2 remember) I found the splice where the black/white wire splits to provide +12V to both ignition units… I cut this out and replaced it with another splice, adding another black/white wire at the same time… This new black/white wire was fed across to the new fuel relay as the coil supply.
Taped the whole lot up, good as new and hardly a noticeable difference to the look of the bike… New fuel relay works a treat, took about 2 hours, tidied the whole rear end wiring up at the same time…[:D]
I’ve even modded my FE wiring diagram to include this change… I’ll try to get the file posted on a web-server somewhere and will add a link to it ASAP…
TIP: DON’T SPEND BIG MONEY ON THE HONDAY RELAY UNLESS YOU PLAN TO CHANGE OUT THE PUMP AT THE SAME TIME… YOUR OLD PUMP WILL PROBABLY TAKE OUT THE NEW RELAY TOO… MINE SURE DID…!![xx(]
Miti
Doh!! [:o)] just paid out £60 for a relay, bike rode 3 miles before taking out new relay. mmmm… = £20.00 per mile plus recovery[:I][:o)][:(][xx(]
Your new relay might not be completely knadged… I saw something on the Sab/Mag/Interceptor BBS that suggested there was a “thermal cut-out” in the module…???
Mine is completely cream-crackered… My fuel pump was seized - I pulled it apart (as much as you can) 3 times and lubed everything in sight… even had it pumping light oil for a few hours… ran as sweet as a nut… Nect time the bike was unused for more than 2 weeks, it seized again… Bollox…!!
I nearly fell out with the seller of the 2nd hand replacement 'cos I hadn’t sussed that the seized pump had taken out the relay module too… My std relay mod and replecement pump have covered a few thousand miles now, so all seems OK…
3 miles is VERY short distance to have had this problem… Is your pump actually pumping, or has it seized/partially seized…?? (do the wire link test to see how it is without the module in cct…)
You might want to check how much current the pump is using… If you replace the wire link with a 10 Amp ammeter, it’ll tell you how much current is being drawn… I’ll check mine and post what seems to be an “acceptable” current… If other folk test theirs too we could get an “average”
Miti
Awesome stuff Miti-Babe…thanks dude…[;)][8D]
My VF500 had the fuel pump removed by a previous owner, I only found out after the bike cut out on me a couple of times.
The relay was ok, so I replaced it with a second hand pump from a CBR600.
Might be of use to someone.
philjo, have you sorted your petrol pump issues out yet? been running mine on difrent set of cdi’s and relay bypassed, but the problem has occured again, got a pump from an R1 comming soon to try that…got a feeling the original petrol pump is intermitently sticking.
pete.
Hi pete,
no I didnt get it sorted, I’v been working away for the last five or six weeks and as a result have not had much time for anything, I do have a weeks holiday booked soon and the wife believes its to catch up with some decorating…
hi phil,wrong time of year for decorating,not enough natural light,well thats my excuse…anyhow,ive fitted a second hand pump from a r1 on the vf,had to alter the mounting bracket a bit but it just squeezes in ok,im having to run the bike with the relay bypassed (jumper wire in relay conector).up to now every thing seems ok.went out last thursday night, did about 50miles no probs…I think possibly the petrol pump was intermitantly sticking,which has caused a intermittent fault on the relay(double trouble)which is more or less what miti-babe said…ps. I think most of the external fuel pumps from bikes 600cc upwards will fit, some easier than others.I bid on about five befor getting that one,they seem to fetch about £30 for one off a more modern bike.
ps.thanks to humph and miti for the info.
pete.
just when you think your winning,it all goes wrong again…been out on bike today,got to trafic lights engin cut out…re started it,sounds like its only fireing on three cylinders,then after a bit of revving the other cylinder comes in.this happened twice in two miles…makes me wonder weather the (petrol pump,relay) problems ive been having have realy been a problem with the cdi’s all along?..has anyone tried to fit a cdi from a more modern but similar set up bike?
quote:
Originally posted by vf petejust when you think your winning,it all goes wrong again…been out on bike today,got to trafic lights engin cut out…re started it,sounds like its only fireing on three cylinders,then after a bit of revving the other cylinder comes in.this happened twice in two miles…makes me wonder weather the (petrol pump,relay) problems ive been having have realy been a problem with the cdi’s all along?..has anyone tried to fit a cdi from a more modern but similar set up bike?
Slow jet blocked?
I have got some new float bowl gaskets if you need to strip the offending carb down…[:)]
hi tim, i could be wrong but i think the problems electrical rarther than carbs,but i supose it wont hurt to get the crowbar out and prize the beggers off and have a look.it just seems to be all linked to the first incedent when i had good sparks but no petrol to any cylinder.on the sabmag site theres a peice on cdis, the discription of what happens when the cdi which controls the fuel pump starts to fail is exactly what happened to mine…anyhow gonna clear some space in the garage ready for another bike, ill sort the vf over winter…
Had four pumps stripped down last night, 1 cbr pump, cannot fit this to the Vf as it is internal and will need some modification, and 3 VF pumps, two identical mitsubishi UC-7 sealed pumps and another off a VF??? similar to the other two but with a flanged seal for the pump side which can be dismantled mitsubishi UC-8 (I think) I mananaged to open this one up, the motor works ok but does’nt pump… I found a sticking valve inside with a little gunge around it, the UC-7 pumps, I checked out the contacts under the rear plastic cover, the heads of the contacts looking similar to a set of ignition points they were very worn and stepped and when I applied power to one pump it run ok with a feint spark between contacts but the second pump contacts arced badly with a bright green spark so this obviously must put more of a load on the other electrics, I think it may be possible to replace the contacts i hav’nt as yet measured what current they are drawing, I have had a look on Mitsubishi’s website at currently produced pumps and they look to be internal tank type though they claim to be 35% more efficient, I will be having a further tinker with the pumps again this weekend and will let you know what I come up with.
Also have a look at this, the pump contacts look similar http://www.xrv.org.uk/media/fuelpumpXRV750.pdf