Fuel delivery problem only on #3 &#4?

Hi Everyone,

Spent some time searching but couldn't find anything similar, hoping maybe someone has a lead for me to follow.

My 5th Gen won't start (55 degrees) unless I add starting fluid to the #3 and #4 (both right side, correct me if I'm wrong). Once started, I can maintain 1.5-2k rpm by cracking the throttle but it appears to be just #1 and #2 with enough momentum to keep it going, as if I then give 3, 4, or both a quick squirt she revs right up without having touched the throttle. So it appears there is a drastic or complete loss of fuel on those two.

Previous FI codes were 1, 9, and 22, but once cleared did not return. I've had the airbox/off disconnected previously trying to figure this out, so I'm thinking I actually did account for the 1, and 9 by having had them disconnected, and the 22 *kinda* makes sense since I've clearly got something going on with 3/4... but after clearing them, none of the codes return (granted I can't ride the bike, so not sure what the set conditions for those codes are).

I checked the wiring diagrams hoping to find something obvious like a shared 3/4 only positive or something, but I'm not seeing anything. Can anyone that's dug in or knows better perhaps shed some light or educated guess on my next course of action? I could just pull everything and check the injectors etc, but I'm hoping that someone might know something that could save me test time.

Thanks in advance,

Jim

 

Air leak?

 

Hi and welcome to the forum. Make sure you post in the introduction forum and we like to see pictures of the bike as well.

Can you give any background on this bike, as it sounds like there were previous problems. Ownership and maintenance history?

What year is this bike?

Have you tuned the starter valves to the offset vacuum specified?

 

I agree with Knight's suggestion about the starter valves, but the engine must be running steadily to do that, which sounds like Catch #22.

It is quite possible for the injectors to stick shut from a lack of use. Why just 3 and 4, no idea. There is a device you can plug into the injector loom that will indicate whether each injector is getting a signal, and you can also (apparently) hear them clicking using the end of a screwdriver as a stethoscope.

But my suggestion would be to remove the injectors and have them serviced (check this video: [video=youtube;Ui9kdU0xigo]https://www.youtube.com/watch?v=Ui9kdU0xigo[/video])

 

See that the starter valves are clean and moving freely with the idle lever.

You can turn both of those starter valves in once or twice, retry idling, then turn them out once or twice, retry idling. (Record what you do.) See if #4 is loose as it should be factory locked in place. Yes that would be a challenge to figure out how to reset it. A call to Honda motorcycle customer service would do.

 

Thanks everyone for the replies. I will post in the intro forum with some bike pics as well. She's a 2000, yellow. I'm the second owner, there are about 40k miles on the odo. The only thing I've done so far is plugs a year ago, and R/R two years ago. This problem has been getting worse for the last two seasons, and the new plugs helped with the intermittent (at that time) issues I was having. I also replaced the pump/strainer in the tank, although they actually appeared fine. I really should do a fuel pressure test as well.

I did a little more investigation today, but I couldn't find my noid light to see if the injectors are all firing! All the injector connectors are getting 12v as they should with the key on, and I checked continuity to the right spots on the ECU connector, so that isn't it.

I also got the injectors to click to prove they are all free as well, or course this doesn't mean they are actually flowing since I didn't pull the rail to see. Anyhow, I think it's likely a combination of of a few things conspiring, which is extra annoying. AFAIK the whole secondary ignition aside from plugs is old... so while I hate throwing parts at anything, I would like to *know* that the condition of coils etc is good, and I find myself so frustrated working in the confined spaces on the bike that I hate doing it, so I think I want to throw some parts at it again. Coils, wires, and plugs again, as well as possibly pulling the injectors and having them cleaned. I'll need to get it towed to my shop, as sitting outside at the house I have few tools, and even less patience.

What do you guys like for sources of parts? OEM only? Aftermarket depending on the parts?

Also in the starter valve, it's a 2000 so it has the lever-less wax thing... and the whole assembly feels pretty sticky to me. I didn't see the comments about trying to adjust it until after I cleaned up.

Thanks again,

Jim

 

Do the 2 standard resistance checks on the coils, both ignition and pulse generators.

 

There are starter valves, and then there's the wax unit. The starter valves are basically small air bleeds that bypass the throttle butterflies. Three are adjustable, the fourth is the fixed reference. The three valves need to be setup so 1 and 2 are the same, 3 is 20mm Hg below 1 and 4 is 10mm Hg below 1. The wax unit bears on a plate that then opens all four starter valves together to give a fast idle when cold. The idle adjuster screw bears on the same plate.

 

If you have a leaking fuel pressure regulator, I've read it can leak fuel into those cylinders flooding them out. Are you positive you're getting no fuel? But that may be a sixth gen thing

 

Latest update. I got it running! But when it rains it pours... I discovered after getting it going again on starter fluid that I could keep it running with the #4 and #1 cylinders... the fuel issue moved from #3 to #1... strange I though. I freed up the stating valve some which was a big help, and got it running on it's own without starter fluid help. I had the tank attached and more or less on it's left side propped against the left handle so I had access to the starter valve and the intakes if it needed starter fluid help.

I got it running on all 4 cylinders and smoothed out presumably after working the starter valve a bit. I then went to put the tank back down in a more normal position and voila... sputtered and died. It's not the pump connection, apparently there must be an issue in the pickup or pump that allows it to suck air in the normal position perhaps?

Anyhow really weird. I tested the theory a few more times and sure enough, with the tank on its left side the bike will run... BUT!! as I was doing this I noticed steam starting to exit the pair reed valve hole on the rear bank... thought to myself it's an awful lot more steam than I should be seeing and looked at the sight glass.... CREAMY COFFEE!!! So I shut it right down. I'm hoping that somehow water got into the oil over the winter in a non-part-of-the-cooling-system-breach/headgasket kind of way... but It'll have to wait until I get oil and can drain, refill and then put the tank on its left side and see if it gets milky again. WTF VFR

 

Maybe the shutdown was due to the tank landing on a breather hose or other vacuum tube?

I was a little worried about the use of the starter fluid. I certainly don't want to worry you but I am wondering if the explosive nature blew the head gasket. Maybe you metered it well enough to avoid a problem. However would you not have caught coolant in the oil with the prior maintenance if it was there?

 

Didn't look at the sight glass prior to the steam incident, so it could have been there, or just happened. Pretty sure I recall it being fine when I put the bike away in the fall. I'm pretty metered with the use of the fluid, and while I suppose it's possible... either way if it's the headgasket there will be a cheap VFR for sale soon with an extra set of yellow body panels and hard bags

Really hoping it isn't the HG.

 

Checked for lines getting pinched etc three times with another pair of eyes... it's got to be something inside the tank. The oil change yielded oil not as bad as I thought, certainly not the worse coffee I've seen, and ran and flushed a second time, staying pretty good condition wise, and ran fine up to temp idling and was controlling temps just fine. No coolant smoke etc... so I guess I'll see once I get the tank sorted and can put a few miles on it if anything is in fact in trouble or if water somehow got in otherwise and no longer is.

 

As Freddy Prinze said, "Lookin' good!"

 

It does sound like you've found your culprit, and it lives in the fuel tank. I'd be pulling the pump and filter assembly out to look for a problem. I also wondered whether you had some electrical problem with the pump power supply that only shows when the tank is horizontal but corrects when the tank is leaned over?

BTW you should be able to do airbox maintenance with the tank in place, just unbolt the front of the tank and pivot it up on the rear bolt, then prop up the front of the tank.