hot start prob "i think"

Dae

Registered
hi,
i have hot start problem well i think it is. start from cold and runs fine until its turned off. come back a few mins later and engine will just keep turning over without firing. leave until cool and starts no trouble. it isnt every time but becomming more regular. engine has done 11,000 miles and it is a 99 bike. TRE and micron cans fitted if that is relevant. someone has said that it could be the thermal temp switch located on the block left hand side on the back of number one cylinder. has anyone else suffered similar probs with any solutions ?? be gentle i am new to busas
 
Do you use the choke (fast idle switch, whatever you wanna call it) even when the motor is hot? Mine is a 2003 with around 350 miles and it sometimes does the same thing. If I use the choke it fires right up every single time. I think yer question has been asked here before and I think the general opinion was that this is normal and that the choke should be used even when hot.

If I'm wrong, someone will be by shortly to flog me with a wet noodle. :cool:
 
No flogging BulletTrain.....But the "choke" is nothing more than a cable attached to the throttle linkage to crack open the throttle and hold it there so you don't have to. In essence it is just a higher idle screw setting. I haven't seen anything that would indicate the ECU is signaled differently other than throttle position.

Sorry DAE, I can't help much on the hot start problem. Are you getting a "code" when it is hot and won't start?
 
no sgnals or lights or anything out the ordinary. engine pulls like a train and sounds typically suzuki. someone also mentioned injector filters pump filter but would these have been done at service intervals??
thanks
 
Sierra,

I thought that was the case. That's why I included the "fast idle switch" comment. I didn't think fuel injection actually used "chokes" anymore. :cool:
 
No they don't use them. But Honda did something different. I don't have details of the system but the Blackbird takes care of "choking" automatically. It even bumps up the idle speed and has no levers or switches. It must have a solenoid that bumps the idle up and is controlled by the ECU. If anyone has worked on that system I would be greatful to hear the details.
 
I am wondering what part of the ignition or fuel injectors would not allow the engine to at least kick when hot? If the coolant temp sensor is failing, the ECU might think the engine is actually cold and has the mixture too rich to run while hot? I am thinking the equivelent of a "stuck choke" on a carburated engine. Is the exhaust smelling very rich when you are cranking it hot and it won't start?

On the other end of the range is too lean. If you are cranking and cranking while hot and the exhaust is free of gas smell, that might tell us something about it being too lean a mixture or a failure of the injection system from another sensor or electrical connector?

This problem has me thinking but I need more symptoms.
 
I found this out along time agao.
the 99-00 models when you turn the key on pressurize the fuel rail so you will have Max fuel pressure. When you then crank it you further pressureize it hench you are TOOOOOO RICH TRYING TO STARTIT.
tHIS IS WAY ON BIGBORES YOU HVE TO HOLD THEM WIDE OPEN OR AT LEAST CRACK THE THROTTLE.
Soory I must have hit caps
 
Check your plugs. I started having the same problem on my first BUSA and I changed the Spark Plugs and it went away.
 
fuel pump wraped?? wraped in what??
engine does smell rich when turning over. if you get off bike after a damn good thrashing put on side stand, leave on tickover it starts to run as if its chocking then stalls and will not restart. but not every time. if i start it up in the garden and get it hot and leave on tickover it runs fine and starts everytime. i have only had bike three weeks and its pissed me right off now i dont want to go anywhere on it . spotted a nice TLR in a local shop may pay them a visit.
 
WHAT?:super: You're not going to let a little problem like this cause you to make a big mistake are you? I am referring to the TL. What you are experiencing is not normal at all and can and will be fixed. Then you will still have the best bike on earth and not the TL (a close second place).

I think what Johnny is referring to is the heat wrap on the fuel pump. If you get the engine really hot it will bake the bottom of the fuel tank where the pump is located. This may cause a fuel delivery problem?

If you can smell the gas in the exhaust on a basically stock hot engine it is too rich. If you are not comfortable digging into the fuel injection system, then find a good Suzuki mechanic and have him/her find the problem. It shouldn't take more than an hour or two to completely debug the system. It is probably a bad sensor or a bad connection/broken wire in the harness.

Please don't let this turn you off to Busas.
 
Just had another thought. When was the last time you checked the TPS? If the Throtle Position Sensor is way off, it may cause your problem. And they usually are off at least a little.
 
went bed over an hour ago 11.50 pm its now 1.15 am and ive just got up! been thinking about this and i just love the bike to much to sell it. i picked up the sensor for the back of the block today and i will fit over the weekend. i have put stock cans back on as i didnt have it set up with them on, i thought it would be ok. maybe thats half the prob. will also get new plugs aswell although these have only done 3000 miles. got to give it a bit more of a go. its gorgeous!!!!
thanks for the reality check sierra flyer
 
Do you have a shop manual? They are excellent to trouble shoot problems like this. They even give you the electrical sensor test procedures. You might want to test the block sensor before you spend the money on a new one (presuming you haven't already). You can pick one up on this board on CD or buy one at the dealer. Otherwise it is intimidating to try and figure that system out. Not impossible but very difficult.
 
sent for workshop manual on disk. got a new set of plugs NGK CR9E as recomended by Suzuki. and also the temp switch(aready ordered) and new coolant blah blah blah. i will try and fit this weekend and see what happens then. also booked in for a remap in two weeks...........fingers crossed.
 
i have fitted new sensor, new plugs and new coolant today. does anyone know ! is the coolant system self bleeding ? or is it possible to get air locks?? have'nt had chance to try bike today so i will run it tomorrow.
 
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