problem still there (part 2)
Turbo Mini Forums

hi guys,dunno if you remember but i was having this problem when getting to around 90mph and she didnt wanna go no further,since thn ive had the head skimmed and new valve guides fitted,valves recut. however,it still does the same thing,

i got it between 90mph and 100mph tonight and it started miss firing,and would go any further,so took me foot off the gas and it continoued to miss then stopped and was fine again.

any ideas?? cheers

come on lads,help me here!

dya rekon its more likely a fueling problem,or ignition??

i did get a new module a while back but it had 3 pins and mine has 2 pins,so is 2 pin an early one??


it started missfiring so i left off the gas,carried on missing then suddenly stopped..

Is it speed or RPM triggered ? because you only mention 90-100mph.
Does it do it in any other gear apart from top.

Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe.

just at the speed between 90 and 100mph.

is fine in every gear/revs until you hit that speed range.

had this problem and found my fuel filter between the tank and pump wasnt big enough also missed if you gave it some welly through the gears hope this helps

love that straight cut scream!!!
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ive got a spi tank so filter should be ok???

might be worth checking it isnt partaly blocked though

love that straight cut scream!!!
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/___|_____
_ (@)___(@)

have you checked fuel pressure when driving like suggested?

yeah did that and seemed fine

its like it overfuels and fouls the plugs,then when you drop to 70-80mph and cruise along for 10seconds or so it goes normal again and stops missing.

Just go to the rolling road....

stuart gurr rekons it sounds like fuel starvation,so what things dya rekon it could be??

SPI fuel tank
regulator
fuel pipe kink??

my mates stripping his turbo mini and hes got an mpi tank and regulator i can buy cheap,dya rekon i should get them?? would narrow it down abit if it isnt one of them..

We had a similar problem on the hillclimber. It was fine in first secoond and third, but on a long straight in fourth it would start to missfire. We eventually found it to be a faulty fuel pump. It just could not supply enough fuel at the right pressure and eventually the float chamber emptied. We sent the pump back to the manufacturer and they confirmed that it was not performing correctly, but could not find a fault. We got a new pump and it has been fine since.

I guess any restriction could cause the same problem. You have the right idea, eliminate one at a time and you should find the problem.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

cool,think il change the pump/tank first then.

hes got 2 tanks,an mpi and a spi, which would you recomend?? is the mpi pump more powerful??

cheers

check the fuel pressure inline to the carb

at the speed you have the problem

this will reveal all!

so you rekon i should t the guage in the fuel line,whack the guage on the window and set of to 90mph lol

was thinking of doing that.

what tank should i get???

We had the same trouble when being pushed hard, when it was on the rolling road we could see the fuel pressure was stable but sometimes it would sometimes seemingly run out of fuel - diagnosis: dodgy carb. (Still on the to-do list - doh!)

i think so dan as this has plagues you for months buddy

this should reveal the fueling problem !

tape it to the window securley should read 3,5 to 4 psi above boost pressure

start at the beginning and dont deviate and go through carefully what the chaps have told you before!
failing that ........................................................................///

REMEMBER dont clutch at straws wildley!!!

go through the the facts methodically
failg that.
the only way is a rolling road session dan

what would be ab-normal then? if it drops when it starts missfiring?

Dan, you say you've checked the fuel pressure already?
Or did you just mean checked it statically?

The hi-speed test should reveal all (just as ben described).

ps - must be handy having a race-track near you where you can experience the joys of 90mph!

D

i checked it before staionary,then took it up the road in first and second and seemed ok,although its hard to watch the guage and drive the same time lol

yeah will take it on my local race track (m25)

i had a problem like this on my not turbo, the problem turned out to be the needle, it was factionly bent, so rubbed and fcuked the jet. i changed them both and its bin fine

doubt mine is bent as i had the needle changed not long ago and was fine,and then it started doing it not long after..

Keep us updated on the next test!

will do chaps,am hoping that it is the pump, hopefully this little test will show me

cheers lads