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1998 honda vfr 800 fi fuel injectors


lawnmowerman

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Important thing is to measure actual vacuum going into FPR along with actual fuel-pressure in rail. Vacuum is used to adjust fuel-pressure dynamically. If you don't have accurate vacuum or bad FPR, fuel-pressure will be too high at idle and too low under load. No way to determine that without measuring actual vacuum levels and resultant fuel-pressure in rail.

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8 hours ago, DannoXYZ said:

Important thing is to measure actual vacuum going into FPR along with actual fuel-pressure in rail. Vacuum is used to adjust fuel-pressure dynamically. If you don't have accurate vacuum or bad FPR, fuel-pressure will be too high at idle and too low under load. No way to determine that without measuring actual vacuum levels and resultant fuel-pressure in rail.

thanks i am sending my fuel injectors out just for good measure but when i get them back i will look into the fuel pressure regulator and if this is the problem or part of the problem i will let you know 

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11 hours ago, DannoXYZ said:

Important thing is to measure actual vacuum going into FPR along with actual fuel-pressure in rail. Vacuum is used to adjust fuel-pressure dynamically. If you don't have accurate vacuum or bad FPR, fuel-pressure will be too high at idle and too low under load. No way to determine that without measuring actual vacuum levels and resultant fuel-pressure in rail.

It's too bad Honda didn't make measuring fuel pressure easier on these models.  The addition of a Schrader valve as in many cars of the era would have made it more accessible to the home mechanic. 

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On 10/23/2020 at 7:08 AM, Mohawk said:

You can buy injectors, just not for the VFR. It used the same ones as some honda civic & cr-v models, as well as Suzuki Early Hiyabusa's. As far as I know, the injectors & fuel regulator are NLA for the VFR.

 

I wonder if the FPR is like some coil packs, injectors and maybe other bits,  a part common to other bikes that could be purchased from sources other than Honda. 

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On 10/25/2020 at 3:12 AM, Grum said:

Did you try having the vac hose off the FPR turn on ignition to prime the fuel rail, did you see any fuel drip from the FPR?

I am going to buy a fuel pressure gage and check the fuel pressure out next week is there anything special you would recommend  for me to do this ? or for checking the fuel system

 

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i am new to checking fuel pressures on fuel injected bike. I am going to town to get a fuel pressure gage is there one you recommend. I will be getting it at Napa or Advanced Auto,  and any quick tips to help me do it would help otherwise i will get directions from the manual. thanks 

 

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1 hour ago, lawnmowerman said:

i am new to checking fuel pressures on fuel injected bike. I am going to town to get a fuel pressure gage is there one you recommend. I will be getting it at Napa or Advanced Auto,  and any quick tips to help me do it would help otherwise i will get directions from the manual. thanks 

 

Before you buy a gauge,  check the shop manual procedure, page 5-47 for the procedure and diagram of the type of gauge you'll need.   I'm not sure you'll find a suitable FP gauge at a parts store - if it's a drive,  I'd call ahead to see what they have. 

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Not really related to FI issues, but thought I'd add my VFR experiences (so far) for amusement after reading some of these obviously bunny questions and obviously master replies. As a pre-amble yes, I do have a multimeter and sometimes it gives me numbers 😁.

The round Africa ride on the icon of reliability and side of the road fixability Transalp was cruelly cut short at the Western Sahara-Mauritania border by Covid. Sadly parted ways and hightailed back to NZ just before Europe descended into the grips of the second wave. So sitting in 2 weeks of isolation after arriving I'm bored, without transport after release and an overly active imagination.  So I buy an English import 2001 VFR800.  Sight unseen. On an internet auction.  A non-runner. Some confusion over milage since we are metric but England is still in miles.  But apparently about 150,000 miles. Ok, it was cheap, but alarm bells should be ringing.

Picked up on a trailer - before money exchanged hands the seller was very particular..."You know what you are buying? I can't say if the engine is stuffed, or the gearbox is ok. Its got a new battery but nothing happens when its switched on - idiot lights on but nothing else happens".  Apart from being filthy it didn't look TOO bad - so even if I parted it out I figured I'd be ahead.

When I got it back to my hosts place -  first check: switch the kill switch on - now at least the fuel pump primes, idiot lights do their thing, FI light turns off, starter solenoid actually clicks but no starter motor. Charge battery - still no starter motor activity.  Strip out starter motor and replace almost non-existent brushes. Replace, hit the button and immediately fires up and runs reasonably well. Sweet.  Short little ride - gearbox shifts sweetly, very gentle revs (since unknown oil condition, other faults?) - hmm running a little warm 120+ degrees C. A bit more investigation reveals a split radiator and virtually no coolant. A temporary epoxy putty repair, dump the old oil (it was DIS-GUSTING!), fill with a cheap oil, adjust slack chain.  Hmm...seems ok now. Fuelled up and headed off home - a short ride of a bit over 600kms lol!! On a wing and a prayer that it would hold together.

7 hours later: damn thing runs pretty sweet all the way without drama, breakdown or incident.  Now I have space & time I've started stripping things down, cleaning, repairing the worst dodgy wiring botch job (but it does have an upgraded RR).  Poor thing has had a MAJOR lack of maintenance - like gummed up throttle cables, years of chain wax and crap, the second ugliest oil change (after the first one!). I dread to think what I will find when I open up the brake and clutch master cyls.  But the thing runs clean and strong.  Suspension needs maintenance, but everything functions.  Not too shabby for a 19 year old, 150,000 mile, bought on the spur of the moment, sight unseen bike.  Looking forwards to becoming familiar with it and bringing it back closer to what it once was.  Nice to know there is a considerable database of knowledge to call on and promise not to ask questions if I can't quantify a measurement, resistance or output.

Cheers.

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Great story there Kiwi and it sounds like you are well on the way to getting the bike right. Might be good for another 150,000 miles! Glad you're back to the land of No Covid.

Cheers.

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5 hours ago, Grum said:

Great story there Kiwi and it sounds like you are well on the way to getting the bike right. Might be good for another 150,000 miles! Glad you're back to the land of No Covid.

Cheers.

Meh, not quite no Covid but only cases turning up (and being dealt with in isolation) are pretty rare and are all sourced from people entering the country from abroad. Prior to the aborted Africa trip I picked up a Transalp in Sydney and rode around to Perth via Cape York, Kakadu, Gibb River, Perth and eventually Esperance by way of a lot of off road and 4WD tracks.  One day I'll have to return and complete the 'lap'.  And then there's the interior to explore.  After Africa.  Meanwhile the VFR is completely missing its arse end while I take a peek at swingarm bearings. One rear shock linkage bearing is a bit dodgy. Shock seems OK but feels a bit pogo.  Maybe dampener adjustment, maybe dampener is past it. Nice to make a connection here 🙂

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  • 2 weeks later...

Update: few niggles to sort out

  • chain - periodic crunching noise related to chain. Removed and found several stiff links. Perhaps corrosion within the pins. Couple of links sloppy - noticeably more movement within a link compared to others. Soaked overnight in CRC, soft brushed as much crap out of the chain as possible. Result - better, but not perfect. Interesting that noise comes as dodgy links leave the rear sprocket, not the front - weird as there is much more movement in the links as they roll over smaller dia front sprocket.  Replacement on the cards.
  • the dodgiest looking abortion of a wiring fix of instruments with seemingly random wires from various points on the instrument flexible printed circuit to crimp on connectors to wires exposed on various wiring clusters. It sort of worked - but shoving a bare wire into a connector plug?? Printed circuit board is seriously corroded on some tracks, so I have soldered wire connections between points A and B where conductivity is non existent. Contact patches for various bulbs is in poor shape too, so now a couple of bulbs are sometimes working, sometimes not. Gauges have taken a bit of a hit somewhere in its past - a mounting point plastic knob broken off.  Hunting for a set of replacement instruments in kms, rather than miles (was a UK import).
  • clutch is a bit grabby and makes squealing girly noises occasionally when hot.  I possibly have a 98-99 model with spring seat/friction spring possibly in the wrong order.  Looked briefly at clutch plates and de-glazed at last oil change. All looked in serviceable condition but took no measurements at the time. Haven't got into the hydraulics yet but (to my surprise) looks like relatively clean brake fluid. Set of new clutch plates and springs possibly on the menu too.
  • Developed (today) an intermittent electrical shut off that seems related to handlebar movement.  Will be on the hunt for grubby or shorting connectors/pinched wires. Had the front fairing off, instruments, lights, fairing bracket (to clean up/repaint), so may have routed wiring incorrectly around this area.
  • Body work has seen better days - several cracks, breaks around mounting points, missing fittings etc.  Surprisingly good condition of paint apart from horizontal surfaces of side fairings and tail section that have faded. The good news: doing a bit of work for a paint/body shop shortly and have been given access to their equipment - hot melt staples, epoxy repair gear, filler.  Hope to swap labour for a paint job. May even look at powder coating wheels and matching engine covers.
  • Other wiring - replaced 18 twisted together and taped over, or badly crimped wiring extensions made to rear lights.  Assume this was done to make removal/reassembly easier with slightly more length to play with.  But UUUUGLY. Soldered, shrink tubed and taped.  And working now.

Apart from that she seems to run pretty good. Saw a brief 150 on the speedo before the road ran out. Love the sound running against compression winding back thru the gears up around the 5-7k range.

What are the stocks of 2nd hand VFR800FI parts like in Australia? Pretty thin on the ground here - I see one 2000 model being wrecked, but no response on parts yet.

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