Cold Start stalling
- Thread starter Dafeimao85
- Start date
When was the last time the air-cleaner was serviced?
Dafeimao85
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Hi GIXERHP,
Valve adjustment unsure as I got the bike at 50k plan to send out the bike for valve adjustment next Jan 25. When mileage is 80k (previous owner told me he did it on 40k). There is also no "click click" link sound (my previous cbr1000rr would give that sound when valve clearence was off).
Stock clutch but had the clutch master cylinder plunger replaced at 60k due to oil seal leaking.
The problem is cold (living in Asia, cold is about ~28deg C atmosphere temperature) cannot start. The bike would fire up 1 sec and stall. I need to crack open until the TPS sensor goes to the top then the bike is able to start. (somehow like telling me it's too lean). I had change the ISC valve and fuel pump, filter and regulator.
Once the coolant temperature goes up abit, I can hit the kill switch and restart the bike with no effort.
Only 3 days ago I realize tps is at the bottom. I adjusted to the middle on Friday and wait for bike to cool down on Saturday, Bike fire up on 2nd try.
Today I am back to the square 1. I check the TPS is on the middle, Co throttle til top line to fire up. When close throttle bike would stall and the TPS will be either in the middle or the bottom.
I did another test by holding the throttle to maintain the TPS in the middle but my busa would still stall on cold.
Its driving me nuts!
Last edited:
Dafeimao85
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Dafeimao85
Registered
Hi All,
The other abnormality I observe was after the initial difficult cold start. I close throttle and rpm drop to ~800rpm and slowly catch back up to 1.2k rpm. During this time volt meter was reading 13.2v to 13.5v (lowest I saw was 13v)
Once warm up the volt then respond to 13.8v to 14.3v.
To confirm its not a voltage issue I also had remove my headlight bulb to ensure the volt was at around 13.8v during that transition period of starting and yet I am facing the same issue. Hence I conclude that it is not the rectifier or generator issue.
Am I correct to test it that way?
The other abnormality I observe was after the initial difficult cold start. I close throttle and rpm drop to ~800rpm and slowly catch back up to 1.2k rpm. During this time volt meter was reading 13.2v to 13.5v (lowest I saw was 13v)
Once warm up the volt then respond to 13.8v to 14.3v.
To confirm its not a voltage issue I also had remove my headlight bulb to ensure the volt was at around 13.8v during that transition period of starting and yet I am facing the same issue. Hence I conclude that it is not the rectifier or generator issue.
Am I correct to test it that way?
Dafeimao85
Registered
Guys I think I can confirm it's the TPS issue. After few hours, again in dealer mode, the - is missing. It couldn't appear until I mess around with the throttle. My guess is that it's intermittent losing signal to the ecu somehow...
Anycase I will have to wait til the new TPS arrival to test. Until then I gona leave it as it as. If not it will be driving me nuts
Anycase I will have to wait til the new TPS arrival to test. Until then I gona leave it as it as. If not it will be driving me nuts
Dafeimao85
Registered
The only thing I don't understand is why the Error code still showing C00 instead of some numbers related to the respective fault
The ecu won't store codes, and unless the bike is in dealer mode when the problem occurs, the fault code won't appear once the issue is gone.
It does seem as though your TPS is working, but bouncing in and out of spec,
and, I'm not positive, but I don't think the TPS gives a fault code when it's out of adjustment, only with a complete failure.
That would explain the idle going up and down and varying over 500 rpms, hard starts, and no codes.
Out of spec valves will cause hard starts too, but more so on a hot engine, and the idle doesn't surge or vary.
I'm still betting on the TPS being your problem.
An old trick we used to use on cars (old cars) was to pull all the electrical connectors one by one and push them in and out a few times to clean the contacts, these days I'd also use a spray can of electrical contact cleaner. We'd also unbolt the earth cables where they connected to the engine and body and give them a cleanup. We did that as maintenance, just in case. It's easy to assume the connectors are bullet proof but they do get corrosion in them from time to time.
Isn't there a method to bench test that? With a multi meter.
He has, but my experience has been that these things are similiar to relays, beause they can bench test ok, but fail on the bike.
I'm not a 'throw parts at it guy', but after enough signs, I will eventually just replace a part to eliminate it as the problem, not as a guess, but that I am fairly confident that is the issue, or at least contributing to it.
I would bench test the new part vs the old part, to see if there are any differences at all too.
Yeah, I have seen too many of these problem threads where the owner pulls the engine to pieces only to find it was something simple all along. I start with the battery and the fuel, it's amazing how many stations have crap fuel in their tanks these days.
Dafeimao85
Registered
Yep
My Dad filled his gas cans a couple weeks ago, 3 five gallon cans, which he uses for his mower, log-splitter, small stuff, etc
Long story short...water in the gas, his riding mower wouldn't run.
He cleaned it out, and got it running.
Before wasting about 13 gallons of gas he decided to try Mr.Funnel, a funnel that seperates water and gas, as it was under $20, and would save about $40 in fuel.
He said that it worked excellent, just as advertised, and he has since used the filtered gas with no issues at all.
Check it out.
Dafeimao85
Registered
Hi Oz22,
You are correct. Base on my understanding on engines, that's why I tackle the ISC idling valve first. Ohm tested was 60 while manual say normal is 80. I replace it thinking it will be okay but not true. (100 bucks gone)
Then I test every single sensor and all turn out to very near or within specs. I then turn to the impossible fuel pump (because bike can still bring me to 150miles easily) but the volume test come out 30% below specs. I replace it (90bucks) and still the same.
Hopefully the TPS (60 bucks) would be the last and restore my love for busa.
Honesty I sometimes still miss riding a cbr1000rr rather than a busa
Hi Oz22,
You are correct. Base on my understanding on engines, that's why I tackle the ISC idling valve first. Ohm tested was 60 while manual say normal is 80. I replace it thinking it will be okay but not true. (100 bucks gone)
Then I test every single sensor and all turn out to very near or within specs. I then turn to the impossible fuel pump (because bike can still bring me to 150miles easily) but the volume test come out 30% below specs. I replace it (90bucks) and still the same.
Hopefully the TPS (60 bucks) would be the last and restore my love for busa.
Honesty I sometimes still miss riding a cbr1000rr rather than a busa
I don't think that you wasted any time or money on that fuel pump.
Not that it is the specific problem you've been chasing, but because they are common fail points on the Busas and Gsxrs, and that your fuel pump sounds like it was already on it's way out.
One less problem down the road.
Dafeimao85
Registered
Hi GIXERHP,
Vacuum leak check done. Was OK. I did not do a compression test as I does not have the tools.
Will take in your suggestion, the next step after changing TPS.
If the TPS measures correctly, and you can adjust it it is good!
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