flat out running problem?? any ideas
Turbo Mini Forums

hi just been finishing a few bits with the metro i had it set up on the rr from peter burgess it was set up at 12psi but to much ignition advance started to cause some problems timing now sorted (to cut a long storey short) built back togeter & running:) goes very well (in my opinion) but when flat out in forth gear at about 4500-5000 rpm it just dies like hitting a brick wall (power wise not actually cutting out). back off the throttle & let it slow down to around 3000 rpm foot back down & boosts straight back up any ideas? i dont have an air fuel gauge in atm but thought fueling should be ok after the rr earlier this year. hope yous can understand my problem thanks scott

Based on the fact ignition timing is unlikely to intermittently change, mixture/fuel pressure seems to be favourite.

hi scott, you realy need the lambda gauge buddy .....the you know where you are .......if the engine not missing, its not going lean maybe ? but you cant tell realy without the gauge...........its a must !

if its black smoking on boost this is boost bog fuel too rich this is the cause.
could be as jamie points out fuel pressure ? ....and or float needle valve port orafice too small some carbs are like that, open it out to 2.9 mm but make sure you know exactley its that first, go for the above firstley in order ,.......... thats my 2 penneth

Edited by BENROSS on 2nd Sep, 2011.

i thought fueling but this was fine when set up on the rr but the bonnet was open with the fan infront ect could the heat of the turbo after a couple blasts be causeing a problem? i have the original fibre glass heat shield on the bottom of the carb aswell. the first couple blasts didnt have a problem at flat out (sorry forgot to say that in original post)

your last post is not the problem if its not over heating
do the above check first!

is your exhaust back box up to the job?
what HP did it make ?

edit:- is the hose to the turbo inlet and filter not crushing under vacume of full boost due to the massive amounts of air the engines golloping ?

Edited by BENROSS on 2nd Sep, 2011.

theres no smoke when on boost or nothing you can see when goin for it no big clouds of black or blue behind me. if i lower the boost on my controler to say 8psi & if this problem doesnt happen after a good few blasts would i be right in thinking iam lean at top when running 12psi

my back box is a janspeed item & my air intake is a decent avonbar job that cost a bomb with a green cotton air filter feeding it. it made 130 at the flywheel 105 at the wheels

Edited by scott the joiner on 2nd Sep, 2011.

Maybe try new plugs -a grade colder ?.

iam running bpr7es (if i remember right) there also fairly new done less than 150 miles anyway

thats not massive power, fuel pressure reg check that and AEM lambda gauge to see where you are ?

the janspeed item is ok to 125 bhp ish.. and the power starts to suffer after that take it from me i had one many years ago.

keep us posted ......be persistent and you will get the result you want

ive got another couple regs kicking about & i'll have to nick me bros innovate wide band kit from his 205turbo hes busy mapping

from my experience the feeling of hitting a brick wall sounds fuel related..try it again but be a bit robert about the choke when it hits the 'wall'

or in English pull the choke out as you hit the wall

Yes i moved to the darkside

Instagram @jdm_brett

Ok brett will give that ago aswell & thanks to steve & jamie for the to trys aswell

This sound like the classic running out of fuel in the float bowl to me.

Coulf be FPR related, i.e. not set high enough. Or simply that your pump will not supply enough fuel and the float bowl is emptying.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

ive got the same problem but i get it at top end of 3rd too. and with an aem i can tell you mines not a fuel issue,

ive tried the t-piece trick to confirm and get the same issue

ive just fitted a new head so i think its angered my mj map

13.95 1/4 mile on a 2.95 fd. Carnt be that hard to beat!

I thought it felt like running out of fuel as it just seems to really die quick one second fine the next nothing I've got another pump & fuel reg I try them & change the fuel filter to

Just an update went to the garage the night & had a look at the profile of the needle that was set on the rr & results were it had only had profile work from a little down from the top to about half way down. The thinnest end of the needle (full throttle end) was total std so I had a avonbar high boost needle that I got a couple years ago now & thought mite a swell give it a go. I believe its really rich buy the look of it. It doesn't idle as well but to much fuel I think so took it for a spin & took it through the rev range in 2nd 3rd 4th seems smooth all the way (apart from idle) took the plugs out when I got back & definitely a bit rich as the plugs are a bit blacker & sooty but rather a bit rich for now than lean & kill it. So basically my rr at peter burgess was a total waist of time & money as he done nothing right

update mine.... leans out

13.95 1/4 mile on a 2.95 fd. Carnt be that hard to beat!

Well eden looks like we've had the same problem I think iam going to buy an innovate lm1 wideband kit today

Check the valve guides havent gone tight due to the heat, ive had this many times with bronze guides. Will literally cut the power and make horrible noises usually when holding it flat out

that is unusuall with mr burgess, but i guess he cant get it right all of the time dont right him off go back and tell him the story and iam sure he will make it right!

some people once they have had a miss understanding, or its not done right never!!! go back to give the guy a second chance ......which the should

im going to profile my needle more at top end and see wat affect it has.

what can i do oil/spring wise to get the dashpot to open faster? as i feel mines abit slow

13.95 1/4 mile on a 2.95 fd. Carnt be that hard to beat!

The general problem is that the dashpot opens too quickly. When this happens the pressure across the jet drops and the engine leans out.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

so wat oil and spring is best, or is it trail and error for each engine?

13.95 1/4 mile on a 2.95 fd. Carnt be that hard to beat!

We have an Avonbar spring in the van and some 10/40 in the dash pot. We experimented until we found what worked best for us.