N/A hif44 idle problems
Turbo Mini Forums

Hi lads firstly this is just NA at the moment, im over the twin 1/4's go out of balance all the time.

anyways!!

I have a hif44 su at the dyno i got it running to the dyno ( rolling road) it has been tuned..

its spot on through the rev range, but there is a small problem.

when on the dyno or driving when you take the foot of the pedal it returns to idle pretty slowly.

it does not drop down so quick like normal.

i was told with the hif44 there is a valve in side i need to remove? so that it does not do this?

is that correct? we are just going on information from a su shop who said that is the problem.

they don't have much of a idea about the hif44 in australia.

my last question will this su be ok to use on a suck through charger?

thanks.

Have you got the correct oil in the dash pot?

Should be fine for suck thorugh.

Edited by apbellamy on 7th Mar, 2011.

Sounds like an air leak to me.

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

thanks lads.

it's a fully rebuilt carb from uk.

No idea what oil is in there the dyno guy put some in.

will confirm this.

I only had engine oil to use to get me there, then took it out & cleaned it & he put some fresh stuff in.

can't see/ hear any air leaks.

he said idle seems not quite right.

could it be the spring?

im glad it's good for suck through, i will be pulling engine out soon to check that shim, might change for a better cam while im at it

WD40 around any mating faces will tell you if its an air leak.

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

oh thats a good tip john. never thought to do that.. will pop down tomorrow to sort it out.

so is there any valve inside or plug i need to remove? so that it does not do this?

sorry for all the NA questions only place i can get a proper answer.

Not heard of a valve. Has he put the correct weight oil in? Any old engine oil will probably be wrong and make the dash pot slower to return

He could be talking about the poppet valve in the butterfly ? The spring can become weak on these & cause problems. Remove it and solder over the hole or replace with a solid disc.

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They aren't on n/a carbs Phil.

yes he put new oil in not sure what, i will check this.

it's a N/A carb & everything is new, looks to be very high quality build polished as well.

everything is spot on & even has the little id tag with it.

to make the throtle cable work i swapped the heat plate around & swapped the cable to the passenger side but it's moving freely. tested it with hand as well.

yes it is returning slowly, i will be using this carb with my sc12 set up.

su middle in australia seems to think my carby is only used on rover v8's and not mini's... god! as i said they don't know much about this su.

my tuner has tuned them alot & it's working spot on apart from this slow return to idle that he does not know much about.

Is your thottle cable OK? It could be binding in the casing and not allowing teh thottle to return quickly enough.

i had a problem with the throttle cable when i first did my engine swap where the casing wasnt in the guide hole properly, other than that, make sure the piston slides up and down freely, that the butterfly has a fair amount of tension to close itself and the damper oil is correct, i use a mix of 20w50 and 3in1 oil mixed around 1:1 roughly.
Could also check that the idle screw isnt catching anything, and the choke works nice and smoothly and returns to off as it should. About all i can think of at the moment

poppet valve in the throttle disc, whip it out and put a solid in like said above. (the pic is a poppet valve is in a bike carb throttle disc. these can cause a high idle or slow to return.

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

ok lads got the car back from the Dyno.

she runs very nice no popet valve in the su. thanks graham.

i think my distrubuter is worn. it's almost staling but idle drops low but picks back up.

if i have the foot on the pedal in neutral and rev it up it has a mis the same spot through the rev range everytime?

it's almost on beat and happens at the same time, where it drops & then picks up like clock work.

I have the mega jolt ready to pop in this looks like my project for tomorrow.

sorry for all the N/A questions guy inly place i can get a good answer.


what are symptoms of a worn distributor

Edited by NickG on 8th Mar, 2011.

my dizzy was worn and it would tun like a pig.... and move the timing all over the place. it would bounce about 15 deg at idle

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!