23 replies to this topic

[motorsorter]

Hi I have a another problem with the busa mini , Car starts and runs fine after about 5 miles running flat out it draws back if you take off the throttle it will pick up and off it goes again also when going round a right hand bend it dies for a bit and picks up slowly the longer you are out with it the worse it gets . I have cleaned the filter at the tank { nothing in it } before the pump, I cannot see any problem with the flow from the tank and their is no restriction in the tank ,I put the fuel pressure guage on at the rail fired it up and its running 38psi steady on rev up as well is this a bit low ? and is their a filter in the pumps ? I havent had it out on the road yet with the guage on it to see whats happening when the power drops any help appreciated thanks

[edsmini]

i had the same prob with my busa setup. it turned out that when the sender unit was fitted in the top of the tank, a small blob of the sealer which goes all spongy and sticky when petrol gets near it was being sucked down into the fuel pipe whilst driving then when i switched the engine off the blob of sealer went back into the tank. that was a headache of a problem to solve, although it might be something else wrong with your car, but i thought i would share my experience just in case its the same problem.

Ed

[motorsorter]

Thanks Ed No sender unit in my one just the pipe out the bottom right corner of the tank and all clean and clear to the pump , I am just waiting on the roads drying so I can get it out and moniter the pressure when it dies out to see whats happining then cheers

[edsmini]

i take it there is a breather pipe in the tank, and if you have a non return valve fitted that it it the correct way round? sorry for the stupid suggestions but sometimes its the silly problems that are the biggest headaches

Ed

[motorsorter]

Hi again nothing been changed it was running well one day and drawing up the next and the breather is clear I also run it with the fuel cap loose but no change

[edsmini]

mmmmmm

the busa pumps have a filter inside them, maybe worth a try. it deffo sounds like fuel starvation. have you put a new filter in it or is it a filter king that you just empty the bowl?
make sure the fuel hose is not trapped anywhere or close to any heat source where it maybe collapsing with too much heat.

make sure the pump wires are good and they are not loose in any way.

it could be a knackered pump

im not sure what else it could be? hopefully some other busa builders on here will post up some possible causes.

Ed

[lukez]

hy,
I also had the same problems. Gon out repeatledly in the right hand bend
and sometimes at accelarations.
I was not able to detact error. I simply moved the original pump back to
the engine to its original position and installed electric
pump http://www.minispare...id=34024&title=
near the tank. electric pump only fill the original busa pump.
all problems are gone. the only thing needed is to install return line of gasoline.

[motorsorter]

Hi I am going to replace all the fuel lines I will pop in to pirtec and see what they recomend for the job and take the pump off and check it out, the fuel line does run quite close to the exhaust , it looks ok but like Ed says it may have gone inside but why it would just fail on a right hand bend mmm

[motorsorter]

Hi just a update on the mini , I have just replaced all the fuel lines with braded lines 5 1/2 metres for £60 from pirtec [attachment=117127:10.09.11 012.jpg][attachment=117128:10.09.11 014.jpg] I also stripped the pump and cleaned the filter just waiting for the rain to stop so I can get a road test done probably next april

[edsmini]

Well, what's the verdict?

Ed

[motorsorter]

No road test yet its still pissing with rain here the car is on road legal slicks , I will let you know after a dry outing if the problem has gone cheers

[cptkirk]

Motorsorter - at the risk of sounding pedantic (not wanting to be, nor am I wanting to teach you how to suck eggs, or start an arguement - more trying to educate in the correct terminology) I feel I need to bring to your attention that there is no such thing as a 'road legal slick tyre'. By its very definition a slick tyre is a tyre without any form of tread & therefore cannot be road legal. Some people use the term 'cut slick', again if it's had a tread cut into it, it aint a slick anymore...

I am guessing that you are running some 'E' marked track tyres, like Yoko A048's, Toyo R888's, Kumho V70A's or similar, the 'E' certifies that the tyre complies with the dimensional, performance and marking requirements of ECE Regulation 30. These tyre do have tread but the very bare minimum so as to be certified a road legal (E) - these are normally known as 'road legal track tyres' or just 'track tyres' - open to discussion if people think otherwise...

All that said and done I hope the new pipe and clean out sorts your problem.

Reading what LukeZ had to say about his setup made a lot of sense to me in that previously the fuel pump would have had a certain amount of gravity feed to it so fitting the original pump closer to the fuel rail and another small pump near the fuel tank to feed the original pump would give the effect of being gravity fed from a bike tank sitting above the engine. The small pump combined with a return line would then not over feed the original pump, it can just take what it needs and the rest gets sent back to the tank.

I look forward to hearing if the new pipes fixed the problem.

[edsmini]

the busa pumps either work or don't work. i have got the same busa setup with the standard pump and i don't have any problems. if there was a difference between running the engine with fuel tank full or nearly empty could also make a difference. the busa fuel pumps do not have a return pipe they use the supply of fuel on demand. im sure it will be something simple that is wrong. Another term for slicks "baldies"

Ed

[motorsorter]

Hi All first of all I must apologise for misleading members and egg collectors with my choice of tyre terms they are in fact yokohama a048 soft compound road legal track tyres to give them thier full title [cut slicks] anyway getting back to the problem I was needing a bit of help with .
Last night I took the mini for a blast and at the exact same point approx [10 miles] it started to draw back and on a right hand bend just died ,I had left the pressure guage on to moniter the fuel pressure on the test, I found the pressure drop when it was drawing back eventually it cut out all together no pressure ,switching on and off the ignition half a dozen times the pressure would rise enough to start it and get a few more yards untill the pump was making a loud screeching noise before blowing a fuse the pump was very hot ,letting it cool for 20 mins and emptying the contents of the screen wash bottle on it I put a new fuse in it and away it went untill it heated up I ended up getting a tow home when I un bolted the pump with the engine running tilting it slightly it makes a strange noise and cuts the engine ,their must be a bearing gone on the motor or something anyway a new pump on order . I knew their had to be someting on the car that was faulty as I have done 1500 with the set up with no problems
Thanks to all for your advice on the fuel problem and the egg collector can get back to sucking eggs Cheers

[edsmini]

good stuff i hope that solves your problem. bloody cars, who would have them

Ed