Irratic idle
Turbo Mini Forums

Hi

I've recently got the mini running and back k the road.

Before I take it to the rr I want to make sure it's all functioning as should be.

Basically it's a bit of a pig to start from cold. It revs up on it's own once it's started. And even while driving off boost it tends to rev up. I've set the idle speed 3 times tonight! It revs up loads when it's cold with the choke out but dies if you push it in a bit when it's cold. Once it's warmed up I push the choke in but still revs irraticly.

Part throttle it's running lean acording to the afr gauge. Flicking between 17 and blank!!
But on full throttle it goes straight to 10/11 and comes on boost lovely (5psi at the moment )
It only seems to work properly at full throttle!

I've got John's map from an old post loaded up on the mega jolt for now and standard metro turbo needle. And 70/90 gear oil in dash pot.

Any ideas on what I should check. Could the Irratic idle and revving be to do with an air leak somewhere, even though it comes on boost ok?


Thanks
Josh

Edited by JT on 26th May, 2016.

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

That is quite possibly an air leak

Yes i moved to the darkside

Instagram @jdm_brett

Ok. So could it be between the carb and head? Or could it be intercooler pipes etc as well?

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

You could spray some easy start all over the manifold ect to check for an air leak. We had one on the manifold when the engine first went in

They don't die, they just get faster!

Ok ill try that. But I'm a bit concerned about the hot turbo etc in that area!

Also I noticed that the fuel regulator makes a kind of mocking noise. And at idle the fuel pressure is flicking about but when I rev it up it settles down. Should I have a steady fuel pressure all the time?

Edited by JT on 27th May, 2016.

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

Air leak between throttle and engine, not in the IC pipes.

Check all carb pipes to make sure they're sealed.

Check the manifold is square on the head.

Check all vac pipes (actuator, FPR, dump valve, MAP/dizzy) some of these are from the plenum or turbo scroll depending on how you piped it.

check carb to manifold seal.

sorted....

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

www.twin-turbo.co.uk

Cheers guys. I'll have a look over the weekend.

Apart from this problem and it getting a bit hot, she fly!
Can't wait yo get her on the rr

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

Heat could be related to it running lean - i.e an air leak:)

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

www.twin-turbo.co.uk

Yes I did wonder that wil.

I'll sort the leak out if it is that and then sort the cooling out if need be.

I've got a minispares 2 core rad. Universal electric fan bolted to it that kicks in at 80 degrees. 72 degree stat, dry decked along with water cooled turbo. Plumbed in from back of the block and returns to top of rad. Plus a 10 row oil cooler with a oil stat.
I may need to plumb in a extra smaller rad somewhere or try and fit a bigger fan or higher quality one like a spal. But we shall see

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

Well I've sussed it!

The dump valve was causing the leak. So I wrapped it up in good old duct tape and it started like a humble 998 lol. Re set the idle speed and all seems good! I've also turned the mixture screw in a bit and it's not as lean. Seeing 14/15 at part throttle and about 17/18 at idle. Then full throttle 10/12.

Waters still getting hot though. Think I need a extra rad....

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

Glad ya found the problem, weird about water temps mine never goes anywhere near past norm, oil temp on the other hand.. i suffer from seeing the wrong side of 100° when being on boost for long period of times

Edited by D4VE on 28th May, 2016.

Oil sits at 90. But I haven't seen any more that 8psi and only for a quick test to show my mate and yest the bleed valve lol.
I've emailed concept about a extra rad. Ive got space for 100mm X 450mm down behind the front valance. Not sure how much they'll quote me mind lol.
The gear linkage is playing up as well lol. Just normal teething problems I guess.

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

I dont think theres a need for an extra rad? Surely somethings up?

Could be the fact Im not running a mechanical fan.
I don't want to use the mechanical fan as it's all so tight with the breathers and other pipe work.
I've also thought about the electric fan I've got bolted to the rad might not be man enough. It's only a cheap universal eBay job. Might try a spal

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985