idle problem help

gedis

Member +
Well lads I have problem with my cars idle, she's hunting and wont idle properly, and vacuum very low -0.1-0.2 it would mean she's drawing air somewhere, or timing is out, i took out intake cam and presurised the intake mani, eliminated couple small leaks, cams timing is perfect also, what else could be wrong? i'm using power fc, big cams, upgraded intake mani and large throtle body
 

turboloon

Member +
it could be yer idle control v/v,also have you tried adjusting the idle scre on top of the inlet,it's under a black rubber cap..:),i'm having the same problem also and have a power f.c,i have fitted a brand new i.c.v,and adj the idle screw dosen't do it as bad now just occasionally it wil give a small hunt but i blip the throttle and goes back to normal,the car is due to get mapped shortly so hopefully get it rectified properly:)
 
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Danza V :D

Member +
Ive had same probelm for months... i did everything with the icv, checked for vac leaks and all sorts, Turned out it was coolant temp sensor.
 

gedis

Member +
it could be yer idle control v/v,also have you tried adjusting the idle scre on top of the inlet,it's under a black rubber cap..:),i'm having the same problem also and have a power f.c,i have fitted a brand new i.c.v,and adj the idle screw dosen't do it as bad now just occasionally it wil give a small hunt but i blip the throttle and goes back to normal,the car is due to get mapped shortly so hopefully get it rectified properly:)
i use aftermarket throtle body so no adjusting screw there, tryed various idle control valves but no luck either, i dont think power fc used icv for idle, i thought it adjust's the timing to control idle
 

Danza V :D

Member +
Have you checked your pcv mate? Just going by what I checked.. Idle problems are common with these I've began to see
 
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gedis

Member +
ya i done that many times, i'm starting to think its one of these problems
gauge reading steady 17-22 in Hg indicates normal engine in good condition.
gauge reading low but steady indicates late ignition or valve timing, low compression, stuck throttle valve, leaking manifold gasket, etc..
gauge reading steady but dropping regularly indicates burnt valve or improper valve clearance.
gauge reading dropping gradually at idle indicates obstructed exhaust.
gauge reading slowly dropping to zero as engine speeds up indicates obtructed exhaust.
gauge reading fluctuating between 15 and 20 in Hg at idle indicates stuck valve or ignition miss.
gauge reading drifting indicates a minor intake leak at the manifold.
gauge reading fluctuating as engine speed increases indicates weak valve springs, worn valve stem guides.
gauge reading vibrating excessively at idle but steady as engine speeds up indicates worn valve guides.
gauge reading vibrating excessively at all speeds (when not under boost) indicates a blown head gasket.
healthy decelerating engine reading should jump to 21 thru 27 in Hg as open throttle released.
 

wildchild

Member +
sorry for going off topic but where did you get your cams mate?
what are the specs and did you have to change anything else to get the cams running properly?
 

gedis

Member +
sorry for going off topic but where did you get your cams mate?
what are the specs and did you have to change anything else to get the cams running roperly?
got them of a lad in here, thei hardened regrinds, not sure about full spec's about 8.8mm lift. Ya the whole setup is different inc. guides, valves, springs, solid buckets
 

turboloon

Member +
i was in for a remap on friday,bearing in mind i had fitted a new icv,and had adjusted the idle control screw and it was still hunting (no where near as bad),matty at wallace has now got it running near enough spot on but he reckoned that my lambda sensor was 'lazy'...it was just taking a bit longer than it should've to react,and he thinks this might be a underlying problem...
 

gedis

Member +
well i'm still strugling with my one, can you check what vacum is yours running at idle, although mine will probably be different due to head setup
 

gtben123

Member +
Hi have u checked the pipe to the wax stat on the bottom ov the throttle body it goes in to the thermostat housing the pipe gets blocked and no coolant gets thru to the wax stat causing a hunt
 

gedis

Member +
Hi have u checked the pipe to the wax stat on the bottom ov the throttle body it goes in to the thermostat housing the pipe gets blocked and no coolant gets thru to the wax stat causing a hunt

i use aftermarket throtle body no pipes coming to it
 
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