Fuel injection issue

[yellowvfr]

Firstly hello all. Recently acquired a sweet looking yellow vfr800fi with 51,000 miles on it. Was sitting up a long time and needs some TLC. So already I have removed the troublesome alarm, fixed a broken track in the dash for the LCD display, cleaned out the tank and fitted a new fuel pump and filter and now it's priming and you can feel the pressure in the pipe to the fuel rail . So I'm now at the stage of starting. I have spark so that's good but no fuel injection. All 4 injectors are the same resistance reading, good earths and wires back to ECU all intact. I haven't put the oscilloscope onto it yet as that's in my toolbox in work. Do the ecu's give problems on the 5th gen bikes and are they just a straight swap. Appreciate any help 

[Rustty]

Hello there,

If it was me I would check out the fuel pressure regulator, maybe pull the vacuum pipe off and flick the kill switch off and on.

If fuel leaks from the vac pipe it's done for.

Or get back in the fuel tank a make sure the filter is hook up right, you could have blown a hose off.

[VeeEffArah]

The 2000 I previously had sat for about 2 years before I bought it.  Would prime and turn over just fine. But never started.  Pulled the injectors and sent them out for inspection.  All 4 injectors were clogged and wouldn't pass any fuel. FI cleaning guy did his thing and once reinstalled,  the bike fired right up.

[gropula]

I agree with VeeEffArah. A bike that sits for a long time will probably have clogged injectors. Pull them out and have them ultrasonically cleaned and preferably flow tested.

[Ughandi]

2 hours ago, gropula said:

Pull them out and have them ultrasonically cleaned and preferably flow tested.

If you can score an extra set of injectors off of some throttle bodies on ebay, I'd recommend getting all 8 cleaned, and have the cleaner flow-match the set of four that are closest together in spray volume!

That's what I did for mine before hitting the dyno for a custom map.
(this is totally not necessary, btw... but if you're a perfectionist or masochistic, it's a great assurance!)

[vfrpilot28]

Definitely pull the injectors send them out for flow test, cleaning, and leak test. 
 

Or buy some off Amazon as Honda used the same FI in their cars. New versus old. 
 

 

[ShipFixer]

6 hours ago, Ughandi said:

If you can score an extra set of injectors off of some throttle bodies on ebay, I'd recommend getting all 8 cleaned, and have the cleaner flow-match the set of four that are closest together in spray volume!

That's what I did for mine before hitting the dyno for a custom map.
(this is totally not necessary, btw... but if you're a perfectionist or masochistic, it's a great assurance!)

Was able to get used injectors without buying anything else.  Lots out there.  Had those cleaned, put my old ones in a bag...will have them cleaned in however long and wash/rinse/repeat!

[Grum]

Check the 10P Gray connector feeding the injectors. Make sure both pins and sockets are clean with no corrosion evident (see attached Note the green corrosion). Make sure you measure a good solid 12v for the injectors on the Black/White wire.

Failing that agree with the other suggestions of professional clean and flow balancing of the injectors.

If you have an O Scope handy, you could verify the Negative going drive pulses to each injector, see attached.

And I take it you're not seeing any Fault Code for injectors from the Fi Light, Sidestand Down?

[yellowvfr]

great info cheers guys. ill try thos suggestions. ill confirm feed to the injecors and then ill just pull out the whol lot and throughly clean it all. ill look into getting replacements too just in case. is there a part number of the injectors i could look up and see whats available. 

[yellowvfr]

im seeing that the injectors are the same part number as the 2.0 honda crv........got the part number of cmsnl website. im assuming they would be the same cc and flow rate

[Mohawk]

Yep same part used in various Honda's of that time period. 
 

Also shared with early Hyabusa's if you are really keen you can buy upgraded Busa 12hole injectors, but might need to change the injector connectors to suit. 

[yellowvfr]

57 minutes ago, Mohawk said:

Yep same part used in various Honda's of that time period. 
 

Also shared with early Hyabusa's if you are really keen you can buy upgraded Busa 12hole injectors, but might need to change the injector connectors to suit. 

OOOHHH now there is a nice idea......would you need to get a power commander or something like that to get the most out of them

[Mohawk]

Yes it would need tuning & probably a 3bar FPR to make the most of it.
 

An alternative if buying secondhand parts would be a 6/8th gen Throttle Body & airbox bottom

half, I believe the 5/6 tops are the same, can't comment on 8th gens top/bottom parts. Then you get 12hole injectors. I believe, but you would have to confirm that the main loom to TB harness have the same connector, but check the pin outs. 

[yellowvfr]

my other bike is a 1980 honda cb900f so dealing with injectors in a bike is all new to me. for now ill clean the original ones and get the bike running and get used to driving it and then look into the upgrades 

[Thumbs]

This guy is the best person I know when dealing with fuel injection, his use of the oscilloscope is very enlightening 

 

[RdChinoy]

After 25 years in this trade. There is only one way to clean an injector and test it and that is to use a machine like Asnu. This machine was so good that I think Bosch bought the company. 
What you want to see is the spray pattern of all injectors should match and look the same no matter what the RPM is. i.e. it sweeps from 500 RPM to 12,000 RPM and you can watch the spray pattern and flow rate. On one set I found one injector would split into two streams. After 8000 RPM. So unless you can do an RPM sweep post cleaning you cant be sure that the injectors are working as good as new. 

Im also looking to upgrade my injectors. Somebody told me these are 320 cc injectors. In which case the Kehin Injectors from the Royal Enfield for 20$ each will work. 
These are 24 hole and I have never seen an injector atomize fuel so well. I mean it looks like little mini clouds that float away in the air. I got them from a Bullet 500 UCE engine. I had to make some holders in derlin to get them onto various fuel rails. Use them on pretty much any engine I build car of bike.  But there is a down side to these high tech injectors. As the holes are so tiny. You better make sure you have a good fuel filter or they will clog up. 
I just google ASNU cleaner and posted the first link I got. Not trying to promote anybody. 

Ps: A quick and dirty way to chk your injector signal from the ECU is to just buy a Largish LED solder a resistor to the positive lead of the LED. Trim the legs to the same length and just push its two wires into the injector back or front and crank. If the LED blinks your ECU signal and wiring is fine. 
This can be used to test so many things on any engine its not funny. The resistor value is picked based on the color of the LED voltage is fixed at 14.4 volts. But just use a 1K resistor and you should be fine. Just get the polarity right or the LED will not glow / pulse.