idle and low rev issues, please help!!
Turbo Mini Forums

Hi guys,

I've finally managed to get my t2 (payed someone to do the downpipe in the end haha), and megajolt fitted.
I struggled to get it idling at a stable speed, and when I eventually did get it going it will not drive at low revs.
It bounces about and doesn't like being put under any load.

So I have noticed that to get it stable the mixture screw is almost as far in as it will go, which I think is odd, compounded by the fact colour tune shows its burning fine (dark blue). But yet it still smells rich to me!

It was running fine with the t3 and dizzy before. I have changed the needle to a avonbar 10psi item, and the jet.
The dash pot has 3 in 1 it

I have also had the head ported and fitted a 1.5 roller rocker set (to suit the cam I did years ago).
The megajolt has just got the a series turbo base map on it at the minute.

The only solution I can think of is to try fitting the original BDD needle and jet?
Any thoughts?

Cheers guys
Stuart

Try the BDD

If something is worth doing, it's worth doing half of.

Should I change the jet too?
It is more involved

Get some proper oil in the dash pot too

In the 13's at last!.. Just

OK will do, cheers

Have you got an a/f gauge fitted?.

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http://www.turbominis.co.uk/forums/index.php?p=vt&tid=489133

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Afraid not its on the to do list, I intend to get it moted and straight to Alden engineering

No joy I'm afraid,
Put some gearbox oil in the dash pot, fitted the old needle and jet. Still no better.
Its either me or something in my new setup.
Once its cooled down I will check the rocker clearances.
It just won't idle steadily, could the high lift rockers be one step too far?

You really need the a/f gauge to get any real joy in setting up the mixture, pissing in the dark without it. Sorry not got a lot of faith in the colour tune thingy.

Main Build
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=489133

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Have you tired looking for an air leak? Could cause an unsettled idle

http://www.turbominis.co.uk/forums/index.p...tid=469104&fr=0

OK so I've got it idleing, I had set the rockers at 0.012"
It still won't drive though, can't get it to cruise even.
If you put your foot down it hesitates for ages then just bounces. Can't under stand it ive got sae 70 in it and the high boost spring.
I couldn't really see or feel an air leak, but I'm going to take the inlet off again to check

Can't really afford an AFR gauge at the minute,
Any ideas I can try in the mean time?

spray carb cleaner around all the inlet gasket, carb etc, if the revs pick up then you've got an air leak.

I'd say gearbox oil is too thick for the dashpot though

http://sucarb.co.uk/damper-oil-sae-grade-20.html

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=151464

saw another post on here about it too, but cant locate it now.

i will buy some carb cleaner this evening then, and try it.
cheers

I'd be checking your ignition timing ( with a light) and change the carb needle and spring back so you don't have so many variables to contend with.

In the 13's at last!.. Just

Right, so its going better.
3in1 back in the dashpot, and manifold removed and refitted. It runs better now but still not right.
It hesitates when accelerating, and then pops up the inlet. it seems to be running rich too up the revs (OK on idle). And getting hot.
With a strobe on its running about 10 btdc at 1000rpm
Now would I be correct in thinking its probably getting warm because of the fueling and timing issue, unfortunately I can't get either of my laptops working with the serial to USB adapter doh.
Nor can I find my old standard dashpot spring, I will order one if necessary.

Any other thoughts? or should I just persevere with the above?

Popping out the carb generally indicates a lean mixture, lean also tends to run hotter, what makes you think its running rich? Does pulling the choke out help things of make them worse?
Also you might want to open the valve gap up a tad to be on the safe side, as they normally recommend a 0.015" gap for high lift rockers.
Also could be worth checking an oil between the ones you have used, as gearbox oil is really thick, and 3in1 is quite thin. Something like engine oil.

Edit: Also a note, I had inlet popping after I burnt an exhaust seat, was causing the mixture to ignite on the intake stroke, also fuel consumption was horrendous.

Edited by jakejakejake1 on 1st Aug, 2013.

OK cheers mate,
I will open the gaps more. And try running with the choke, before I change the oil again.
I think I've just got confused somewhere with the fuel issue.
I hope its not a burnt out seat it's only just been refitted after a rebuild.

Yeah that would be a shame, if you have access to a compression tester it could put your mind at rest.
I think it's very important for people not to guess their mixture based on smell etc as there are similar simptoms that can be caused by both a rich and lean mixture. Especially if said person isn't too versed in tuning cars, as it's very easy to make things worse and cause some damage.

Think I've got it sorted yay

The magajolt had a dodgy power feed, so the timing was way off.
I've got some refining to do, its still running a bit lean, but then the needle is completely wrong.
Need to get it mot'd then to rolling road.
Hopefully drive it too 'mini in the park'

To answer an earlier query the only other hif44 Carburettor fitted with a jet with a larger bore was fitted to the maestro and montego turbos I believe all minis fitted hif44 carburettors regardless of needle size have the same jet bore size.

Own the day