2000 Hayabusa Only Running On 3 & 4 Cylinders.

David Offor

David Offor

Registered
Hello all.
This is my 3rd post regarding my bike problem.
The bike is only running on cylinders 3 & 4.
These are the things I've eliminated (swapped, changed, measured) -:
1. Spark plugs, swapped from running cylinders to non running.
2. Map sensor, swapped for another and checked resistance and vacum.
3. Coils, swapped for another set and swapped between working cylinders.
4. Power to injectors.
5. Swapped another set of injectors and swapped between working cylinders, also had a previous set professionally cleaned, tested for spray pattern and holding pressure.
6. Water temperature sensor, fitted a new one and checked resistance at book spec temperature.
7. Throttle body sync.
8. Fuel pump pressure test and check to see fuel down all 4 throttle bodies, all good.
9. Compression test, all at just over 175psi.
10. Oil and filter change.
11. Checked valve clearances, all exhausts were tight, so fitted new shims, now all clearances on exhaust and inlet are correct.
12. Double checked timing, 15 pins between upward 2 arrow on exhaust cam and upward 3 arrow (or 2, can't remember) on inlet cam, with inspection cut lining up with sprag clutch cover timing mark.
13.i have had the crankshaft sensor out and inspected it for damage, looks ok.
14. Measured resistance on sensor in air box at book spec temperature, ok.

So, I have a spark, fuel, compression, timing is correct but only running on two cylinders, it's got me stumped at the moment.
Any suggestions or help would be greatly appreciated.
Thanks. Dave
 
You've obviously thrown enough money at the problem.
But an 02-07 ecu upgrade is worth doing just to be able to flash the ecu.
I would be out of options in your shoes and try that as a last resort, but that's just me personally.
Unless there's a short somewhere in the harness...or in the ecu.
Sorry, but I'm reaching at this point.
Without being there personally, I'm out of ideas.
Where are you located? At this point, you need a fresh set of hands and eyes.
Maybe one of us is close to you?
It's going to be something simple and stupid, always is once a mess gets this big.
Don't ask me how I know that, lol. Sorry I can't be of more help, I feel for ya.
 
Hi sixpack
Thanks so much for your suggestions.
I did try another ecu a while ago but that was regarding a out of tank fuel issue I had.
I'm now running an in tank set up but problem still remains.
I'm a mechanic of 29 years, so I've done all the work myself, saving me a fortune and most of the parts I've swapped were from a known running bike.
Today I managed to confirm that I have......correct valve clearances, correct timing, fuel at all cylinders, sparks at all cylinders and even compression at all cylinders, correct fuel pressure, 4 functioning plugs, 4 functioning coils.
It's a mystery because even if the ecu was faulty, I would expect it not to either give a spark or operate the injectors on the dead cylinders....compression+spark+fuel=BANG in anyone's book or so I was always lead to believe.
Do you know the procedure for fitting a mk 2 ecu? I know that the mk 1s are not reprogram able or able to re flash them.
I'm loathed to give it to a garage because I'm sure I'll get to the bottom of it, with a little help, fresh eyes maybe, like you said.
I'm in Staines near heathrow, bit thin on the ground for bike shops and most dont like technical chats with out the obligatory £200 to book it in.
I have a cam shaft sensor on the way, hopefully get it tomorrow, I'll update when I've fitted it but I'm not. Optimistic, it's pretty much the only thing I haven't tried yet.
I'm thinking your suggestion of ecu is the most realistic solution but still confused with the fact that I have spark and fuel but no bang, weird.
Anyway thanks again and I'll post some news tomorrow :). Dave
 
Update.
New Camshaft sensor turned up and fitted, no difference.
I've got the ecu off, going to see if there's anywhere local to Staines that can test it and check good ole eBay for a confirmed good one.
Also does anyone know the procedure for converting to a mk 2 busa ecu? I can search but just being a bit lazy by asking here :).
Thanks again and I'll post when I have any new news.
 
I've been thinking that if the ecu is sending the spark at the wrong time to 1&2 or opening the injectors at the wrong time on 1&2, this could give my problem?
 
I had a similar problem with a Gen II that I bought a few years ago that had been in an accident. It was only running on cylinders # 1 and 2. In this case the problem was that the force of the sudden stop had dislodged the # 3 and 4 throttle bodies from the manifold boot enough to allow outside air to be drawn in. From the description of all that you have checked already I would imagine that you have had the throttle bodies off multiple times, but if not, this might be a place to look. With fuel, air, spark, timing and compression on those cylinders this could be the cause, either from what I described above or some other issue that is allowing unmetered air into those two cylinders.
 
Here's a link with the info on the ecu upgrade to 02-07.
It sounds like it would be as cheap to try it as to pay someone to try and fix yours, and you'de have the benefit of the newer ecu(able to flash). As well as not having your pride hurt by some ripoff shop, and I completely understand that too.
I was a professional mechanic years ago also(thank goodness I got out of that).
I'm never to proud to ask for help, but no way could I put my bike in a shop.
We know electrical gremlins can be very hard to explain sometimes, so maybe an ecu is the way to go.
Any way you could try the other ecu you did before?
I'm betting it's a short in the harness, or a faulty ecu.
I chased a come and go short in a 94 ZX7 Ninja I had years back, similiar to what you're going through, worst experience ever.
Turned out to a be a break in a wire buried deep in a bundle of wires in the main harness. All the wires were straight there too.
Strange and absolutely awful. One little wire.
Good luck.

https://www.hayabusa.org/forum/threads/16-bit-ecu-to-32-bit-conversion-how-to.166099/
 
Hi samaki, your throttle body rubber mount suggestion makes perfect sense, sucking to much air would kill cylinders, I'm on the bike now, so I'll remove the throttle bodies and check for splits or damage :).
Hello again Sixpack, thanks for understanding my dilemma, most people tell me to give up and sell or give to a shop to sort but I'm too stubborn for that but will always ask for help, if I'm stuck, I don't think I've ever met a mechanic that enjoys electrical problems, I will definitely read up on your link and get involved with that convertion, even if it's not an ecu problem
I am back however with the timing and around midnight last night I got the mirror and torch down between frame and cam end cogs and noticed something interesting, which has me a little baffled and if it's wrong, it is probably my problem the horizontal arrows are out of alignment, even tho the crank timing mark and 15 pins/vertical arrows are correct, it makes me think I've got both cams a tooth too far anti-clockwise, I'll attach a pic of how I believe it should look and after rotating the engine.
The book is a little vague on such an important procedure.
P.s ignore the red and green marks, this is a diagram from the Internet.

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The only way I can get the horizontal arrows to continue to line up, is to set the pins at 16, Wich is wrong according to the book.
 
When the engine is running, do cylinders 3 and 4 produce any heat on the exhaust header? Meaning are they totally dead or producing power to a limited extent? If you briefly touch them after start up is is quite evident. A laser thermometer would work better if you have one, or chalk on the head pipes. If this issue was cam timing related, or a sensor, it would affect all four cylinders, not just the two.
 
I now have the timing how I think is correct (see new exhaust cam photo) and compared with book photo.
Unfortunately, now the bike won't even fire, I've noticed that, with all 4 plugs out, holding the throttle open and cranking, there is a single burst of fuel mist from all 4 injectors, then no more fuel being injected.
I was under the impression that the fuel would pulse in in the firing sequence and carry on injecting with cranking.
Seems like one thing after another with this bike

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No firing at all on 1&2, no change whatsoever when removing coil lead but holding coil with a plug in the end of the coil away from the chassis, will give a good spark across approx 2cm gap, same for 1&2 cylinders.
But now this problem with the fuel injecting on all 4 cylinders, suggests that the mapping in the ecu has become corrupted, I also thought maybe the crankshaft sensor has failed?
I've also fitted a new camshaft sensor, so I know it's not that.
 
Confirmed working ecu with wiring loom on the way from eBay, will try ecu first, if no change, then will fit loom, hopefully some progress soon.
 
Seems like 'batch' firing on a hayabusa might be normal and maybe my new timing set up is causing an issue, will check throttle body rubbers tomorrow.
 
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