Hayabusa Gen 1, Misfiring, Suspect Injectors?

[David Offor]

Hello again all.
My bike is continuing to test me.
After getting to the bottom of a previous misfire issue (excessively worn valve stem guides, replacement good head fitted).
I now have similar symptoms-:

1. No power
2. Spluttering and coughing.
3. Inconsistent 'Puffs' of light/flame, under throttle flaps under light throttle twist (with tank up and airbox removed).

I've tested-:

1. No codes.
2. Good spark at all coils (tested with all plugs out, earthed out and cranked with fully charged battery, making sure plugs and coils eliminated).
3. Tried another ECU (known to be good).
4. Compressions around 150psi on all 4 cylinders.
5. Tried another map/IAPS sensor.
6. Put the stock exhausts back on the bike
7. I have no power commander, an alarm or any other non standard fittments, it's a big standard gen 1 but I have converted it to a 'pump in tank' set up.


I've taken out the injectors and removed the shields/fine filters, after filling them with fuel, it drains out of 3 very slow and the other one, not at all, so I reassembled and tested without the filters, no difference.
I've rigged up the injectors to fire outside of the head, to view the pattern/flow/sequence.
This is were I'm a bit in the dark because they seem to be squirting a jet and not a spray pattern, also one squirts less than the others.
I'm thinking I've got partially blocked injectors but don't want to chase and throw money at a 'red herring'.

The bike was running fine, no odd engine noises, not overheating, it just started missing, then became unridable.

Thank you in advance, to anyone with any suggestions, I'll entertain anything. Dave.

 

[K-Man]

Exactly like mine. Following this intently. Glad you're testing your injectors

 

[GIXERHP]

What year is the bike
How many miles?
What is your fuel pressure?
When was the last TB Sync?

 

[David Offor]

It's an RY model 2000.
40,000 miles on the engine, 16,000 miles on the replacement head (according to the advert).
I haven't checked my fuel pressure yet, I'll do that today, also I'll do a leak down test, to eliminate leaking valves/head gasket/rings (compression test is usually good enough to eliminate rings and head gasket).
I synced the throttle bodies 8 months ago (after the bike was running well, with the replacement head) but then I went traveling for 7.5 months and the bike wasn't ridden, it ran fine, for about 5 rides, pulling even and strong, no overheating but then started to splutter and misfire again, now unridable.

 

[David Offor]

Exactly like mine. Following this intently. Glad you're testing your injectors

it does point to injectors but it could also be a stator or crankshaft sensor problem, injectors being told to fire at the wrong time or like GIXERHP has suggested pump pressure.
Hopefully have some news later today .

 

[David Offor]

Update-:
Easy check first. Pump pressure.
Tried 3 different gauges and all showing at least 15psi low and even lower under cranking.
I'll try and attach a video link.
So, it's looking like a failing/failed pump (I'm hoping).
P.s the red number the arrow is pointing too is 20psi.

 

[David Offor]

Pump out, new one ordered.
Hope this gets to the bottom of my bikes underlying problem.

'Pump in tank' pump, on the left, 'out of tank pump', on the right.
Physical size is different, so they are not interchangeable.

 

[David Offor]

The injectors pattern/squirt

 

[David Offor]

Fuel pump test, showing low pressure, under cranking and priming.

 

[David Offor]

New pump, built up assembly, now time to test.

 

[David Offor]

Looks like the bike is fixed, at last.
New fuel pump fitted.
Compare the difference.

 

[David Offor]

Injectors back to full strength but No. 3 injector could be an issue, I'll remove the shields and see, if I get improvement and better consistency on the spray pattern.

 

[David Offor]

Ignore the stalling on lifting the tank, it ran outa fuel.

 

[David Offor]

What year is the bike
How many miles?
What is your fuel pressure?
When was the last TB Sync?

All sorted GIXERHP, the fuel pump test gave the results I was hoping for, bike is flying like new again, thanks for the input. Dave.

 

[3WheelerMod]

Thanks for this.. This is awesome... I was wondering how to test this.. I tried to test one injector at a time.. Now that I have seen this I am assuming you can't do this?
Also... I thought I read somewhere that you should be getting about 43 psi from the fuel pump. Is that correct?

Picture of my injectors in my 3 wheeler

 

[David Offor]

You can't test one at a time, using the bikes fuel 'rail' because fuel, will just pump out of the empty injector holes (unless you can block them off) but I don't see the point in testing one at a time because you are trying to replicate what's happening, during cranking (injector solinoids operate, on/off during cranking).
I believe the book says 42 but tbh anything over 40 and under 50, I'd be ok with.
I've attached photos of the injector plate, I made up (make sure the pressure won't shoot the injectors out, it's mainly to hold the fuel rail together) out of a peice of plywood and the pressure tester, made from some copper plumbing bits and gauge (make sure you use a gauge that goes high enough), test the gauge is working/air leaks, with an airline blower, before testing on the bike/trike.
Dave.

 

[David Offor]

Adding this thread here because it's relevant to fuelling problems, a modification, to bypass a blocked filter, that is located in the black hosing, that the pressure regulator plugs into on the 'pump in tank' set up.

https://www.hayabusa.org/forum/threads/fuel-filter-mod.175027/