bloody minis! pt1
Turbo Mini Forums

Why are they so fickle?!

LOL

Haven't driven my glitter one since Santa Pod... but I took it out for a blast tonight as the weather is lovely!

Anyway, since blowing a hose at avon its not been boosting right... and tonight its been running very roughly.

So there I was driving along and its back to its old tricks of missing as it comes on boost. After a few miles it slowly starts to clear :cool: So I carry on driving untill I'm about to run out of fuel.

By this time its running better but its still not right. It STILL misses as it comes on boost (then clears). But it will only boost to 8psi... sometimes only 5 psi!! Now what I don't understand is how it manages that with a 10psi acatuator!

If I flick to hi-boost it'll boost past 20psi (although not without some pops!!!!). So its not the turbo

Oh well thats minis for you!


Alex

AlexF

you have had this problem for a while alex on and off ?

there is always a reason!

are you sure its not fuel bogging !
as you have 10psi then flick the switch for 20+

running on the same needle!!!

think about this !

its not suppose to run 20 lol... the bleed valve has fallen apart with vibration and unscrews a little to far!

it was running 10 and 16 on the same needle....

It could be fuel, but its fact this only happens as you come on boost thats the issue... it also goes away every now and again!!


I ecpect a new ignition system (mega jolt), rebuilt carb, new pump and regulator will solve it hehehe

Alex

AlexF

Bit of a long shot maybe.........

Is your fuel pressure reg either sticking (not really possible I know) or maybe gummed up? So at lower boost levels fuel pressure is not rising properly with boost pressure hence it then misses as its lean? And then the 20+psi is enough pressure to shift the presure reg??

nah... 20 psi is miles more boost...

once you switch from vac to any level of boost... even 0.5 a psi... it clears and pulls well.

20 psi leaves it detting hence the nasty noise... I only flicked the switch to hi to check the turbo.

Alex

AlexF

Stick a pressure gauge on it and figure out what's happening.

Simple.

I'll be very dissapointed if this isn't sorted by friday - these aren't exactly complicated engines or fuel systems!!!

Base fuel pressure decaying on vacuum? and then onto boost raises pressure up?

Agree with Dave, get a gauge on it

Its not racing on friday... not because its not ready but because I want to run the black one at more than 6psi and see what it runs!

Alex

AlexF

dashpot oil? i know its a simple one but it causes missing as coming on boost if there isnt any!n

yep good call iain, been caught out with that one before

check that st8 away... and have tried a thick and thin oil...

Like I say I'm not too bothered about it... just annoyed at the inconsistancy of cars LOL


Alex

AlexF

i don't really understand the fuel systems that well but...

it wouldn't have anything to do with the actuator would it? When you are limiting the boost via the actuator it struggles to make the 10psi it should, but when you bleed it, the boost shoots up.

the acatuator should open before 10 psi... but it does and seems to be any where between 5-8psi.

It could be the there's not enough pre-load... or somthing like that.


Alex

AlexF

Is it to do with where the fuel regulator is taking it's pressure from?

Have you taken it from the standard outlet on the plenum?

I put in an extra outlet on the plenum specifically for the fuel regulator as I didn't want to be bleeding air off the line to it. As would be the case if you put a T piece in the line to the actuator, and you ran a bleed valve, which you do.


Wil

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

In all honestly I dont know Wil...

Its a very good point, I don't do that on my black mini, but I didnt do the plumbing on the glitter one.

There are lots and lots of pipes as well as the two solonidos to make it two stage boost.... I haven't bothered looking at what does what and if it could be improved............................ yet :)


Alex

AlexF

A fuel pressure gauge?? Nah.. No use mate.. :) LOL

Fucking grow up Vegard

I'm just pulling your leg. You know it Tom :)