Idles too fast
Turbo Mini Forums

Hi guys, im new to this site and i hope you can help me with my new engines teething problems.
Ive just got it running, however i cannot get it to idle at less than 1600 rpm and every time i turn the idle screw out to lower the revs it cuts out. It seems it will only run if the butterfly is partially open. It will idle higher and it revs up really well.

Im running a 1293 metro turbo with garret t3 and a SU HIF carburettor. The overflow is blocked off and all the holes from the plenum to the carb are open (ie: not restricet by the gasket). This is what i was told was the correct thing to do with a turbo'd engine.

Ive tried to use some choke, but this also causes it to cut out.
None of my charge cooler pipes are attached. (dont think this would make a difference)
The small pipe that goes from the drivers side of the carb, just above the overflow, to the top of the carb at the front isnt blocked.
There are no air leaks from where the dump valves connect to the manifold.
Adjusting the mixture doesnt make a difference.
The Dashpot has been cleaned and oiled and is moving nice and freely.
The Float chamber is clean and both the float and jet move freely.
The inlet manifold is tightened up to the head, so there are no air leaks here.

Im stumped!

Hopefully i have helped to narrow down what the problem may be. If anybody has any ideas then it would be much apreciated.

Thanks guys.
ps. Happy new year!!!!

sounds like its to rich at idle try leaning it of and adjust the throtle as you go.

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

Cool, i'll try that. not sure if its too rich tho as i have checked the plugs and they look ok.

Hi,
Timing?
Disconnect vac advance pipe, then set it up :)
Cheers,
Gavin :)

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My Mini build diary

are you running a dizzy, when i was running one before i went to megajolt i had the same problem as you it turn out to be a duff module, borrowed a mates on and it fixed it straight away

ive tried to set up the timing with vaccum advance off but it still does the same.
As to weather im running a dizzy, i am so i could try and borrow my mates.

Cheers guys!

Does it just cut out suddenly or wind down and die out after a few seconds?

have you checked the fuel pressure?

It just cuts staight out, it doesnt die after a few seconds.

I believe the fuel pressure is correct. i will check it tho.

thanks

keep trying though your get their let us no what it is?

Hi guys,

Ive tried a few things on the weekend all of which made no difference. The engine still cuts out when you try to adjust the idle to below 1500-1600 rpm.

Here is all the stuff i have tried:
.Done up all connections to anything connected to the manifold and carb
.WD40'd all connections and gaskets around the carb
.Checked that the manifolds were all fully home against the head
.Vaccum advance hose-no leaks, tight fit
.blocked off the hoses which connect from the dumpvalves to the inlet manifold
.tried to lean off the mixture
.blocked off the brake servo to manifold vaccum hose
.bloked off all the plenum holes. Ie: dumpvalves and air inlet. This caused it to die through air stavation suggesting no airleaks in the system
.adjusted the fuel pressure regulator
.tried a spare carb but this only made it bubbly. kinda sounded like it wasnt firing on all cylenders. however, i adjusted the idle screw and it cut out again like all the other times
.took off the blanking off hose so that the overflow was free
.attached all turbo charge cooler pipes

Im completely stumped guys. If there is anything that i havent tried, please let me know and i will give it a go.
Thinking of possibly trying yet another carb if i can find a cheepish one on ebay just to test.
Also, just before i go, it wouldnt be because i have such large valves would it? They are offset 36mm and 32mm.

Any ideas will be much appreciated. Plus you never know, if one of your suggestions wins i might buy you a pint!
Cheers guys,

Didnt mean to say "wins".
But if one of your suggestions does fix the problem............you know.

you didnt try the module yet well if you did you didnt say. its worth a go mate for the case of unscrew old one and borrowing your mates one. that what was wrong with my car in the end sounds like same symptons as i had and i tried everything too.

cool. i completely forgot to check that. will do so as soon as i get a chance

Cheers mate

WOOO bleeding HOOOO!

Thanks very much Mr Matty King. You are the proud owner of a pint of beer if our paths should ever cross.
It was the module so i will be buying a new one asap and get the car on the road.
Thanks very much again for helping.

Cheers, alastair

no worries mate its nice to put input back into the site. information can be price less and save you hours. good luck with the rest of project

My module had been on its way out at chrismas. the car was stumbling when trying to part throttle accelerate at 2000 ish rpm unless you buried your foot. It was also firing too early when cranking, which made starting a painful process.

I changed the module and it no longer stumbles and starts at the turn of a key.

Edited by minimole23 on 12th Jan, 2008.