Miss at idle and a few other things.

[gherb]

Hi all,

I have an ex cop VYII done 280000kms, Here are a few issues i have had, Door lock actuators failed, I have removed them, dismantled, cleaned motor commutator/brushes, and fitted new microswitches (although they tested allright) That fixed the prob, Its a bit off a mission but being a tight arse I hate paying for anything!!
My diff makes a horrible clunking noise when coasting, accelerating and decelerating, checked drive train and there is no play, so it is in the diff somewhere.
The stereo turns on by itself (sometimes) after exiting the vehicle, thats an easy fix, I have to turn it off manually before getting out.
Steering "shudders" at low RPM (at turning extremes) , I have read that this is because hydraulic hoses are too small in diameter and fixed by installing larger diameter hoses, I can live with that though.
I now have a miss at idle ( I can feel it up to about 2000RPM) The fault started intermittently, but now is there all the time. The exhaust smells really rich and I am using more fuel. (15ltrs+ per 100kms) around town. Also it is hard to start sometimes, hot or cold. It accelerates perfectly throughout the rev range (once past 2000rpm), but misses when coasting at 50kms (revs at 1500rpm). It stalls sometimes too. I have renewed the spark plugs and checked all vac hoses, injectors, leads, sensors ( new O2 sensors), Cleaned the throttle body, IAC and TPS. I cannot isolate a single cylinder miss, it seems to be missing on all cylinders. I have sprayed water all over intake manifolds and not got a drop in RPMs so effectively ruling out an induction leak. I cannot check the EGR valve, nothing in the manual about a testing procedure. I cannot get the purge valve solenoid to actuate when applying 12 volts ( I turn ignition on, there is 12 volts at the plug but when i connect/disconnect the plug nothing happens) I have bypassed it and still the same miss. There are no faults logged, and the check eng light has not illuminated. I am guilty of occasionally running it on a mix of avgas and unleaded! ( i get small amounts for free ) This might have something to do with it , but in my experience, higher octane fuel will affect the O2 sensors and the cat convertor, both of which seem fine. I am not sure if it would affect charcoal filter though. Well thats about it, anything I have missed?? I am thinking The ignition unit under coils or mixture problem. Thanks guys.

[TheIceman]

sounds like the classic dirty injector problem. at 280k if they havent been replaced they are sure overdue. this will fix alot of idling issues

[gherb]

Thanks for a quick reply theICEMAN
I might try some injector cleaner then??
The pump is working, and the filter is not blocked.

[wana s' charge stock vt]

prob want to get them properly cleaned and tested. i had 1 quote for $110 to do it all pro. i've prob nearly spent more than that on bottles of injector cleaner with no results.

i herd it keeps good injectors clean, but wont fix a dirty or clogged injector.

[TheIceman]

thats it, injector cleaner wont clean dirty injectors and is a waste of cash. they sell sets of cleaned up injectors for V6's on ebay for around $100.
replace injectors, if its still running like crap get it looked it.

[wana s' charge stock vt]

Remanufactured Holden VT VX VY V6 Bosch Fuel Injectors - eBay Other, Air Intake, Fuel Delivery, Car Parts, Accessories, Cars, Bikes, Boats. (end time 27-Jun-10 13:14:24 AEST)
he's the one that said he'll clean mine for $110. but he sell's your type for $100

[gherb]

Thanks guys,

Will try some injectors then, will keep you posted

[TheIceman]

Thanks guys,

Will try some injectors then, will keep you posted

youll have to pay for this one, you cant clean them yourself any cheaper. (referring to your first post)

[gherb]

Just got my injectors checked and cleaned today by a friend of mine, he said they were in great condition and flow checked well. refitted them but the miss is still there I removed my MAF sensor and cleaned with brake cleaner but made no difference. I fitted new leads yesterday as I saw some flashover between leads but no improvement on idle miss. I am running out of options.. any more ideas???

[one_and_only2004]

Have you replaced the coil packs? That and check the gap on your spark plugs - one of mine wasn't correctly gapped out of the box so it missed occasionallly

[wana s' charge stock vt]

haa what a bitch, i'm getting new injectors on monday, but you just killed all my hope's of it solving my little miss. seems pretty similar to yours, upto about 2000rpm/slight bit of throttle/bairly noticable but still annoying.
i've try'd different coil packs and made no difference at all, changed the plug gaps a number of times but no joy from that either,and a different tune but still no go. i've been thinking mayb its the lim gasket leaking but not to keen on changing it yet.
.

[gherb]

Yep I have checked the plug gaps twice!
I havnt tried new coils yet but a friend of mine just brought a VT wagon, so I might try swapping some
bits over if they are compatible. Will keep you posted.
Wana s'charge.... whats the Lim gasket?? lower intake manifold?? I have tightened my intake bolts, they all were a little bit loose. It does feel like an induction leak I just cant find it. Damn thing is stalling more often now.

[wana s' charge stock vt]

yeah, lower intake manifold. if you havent already, while its idling you can spray water/carbi cleaner/throttle body cleaner, ect around the manifold join,injectors,hose joins or anywhere where it could leak air from and it 'should' suck it in and change the rev's a bit. i havent had any luck with it thou, but been told it works.
and the coils will be the same, try n swap the whole lot, (coils and dfi plate under it)

ya dont have a little bit of oily crap under radiator cap do ya ????(another sign of lim gasket gone)

[gherb]

yep I have tried spraying water around and no drop in Revs, I tried removing fuel regulator hose from back of plenum to see if there was fuel in the line (indicating leaky diaphragm) but it was dry, it did seem to run a tiny bit smoother when i plugged hole in plenum though. I would like to check fuel pressure at rail to verify correct op of regulator. My radiator cap is mint, no sludgy crap or anything,..

[wana s' charge stock vt]

sh!t hey, what a pain.
lol i just ended up convincing myself that its ment to run like that and gave up for a couple of months,was over it, and was hoping whatever it is would just sh!t it self completely so i could pick what was wrong. .
i've never tested the fuel pressure/reg properly thou, disonected it the same like you said but had no leaks.. it didnt change the revs at all thou, i thought it's ment to run rougher when vac lines disconnected from fuel reg..

(just a thought/theory) but may have to higher pressure at low rpm and with stuff all throttle, and could cause it to flood it a bit and slightly miss, run rich, use alot of fuel)

[wana s' charge stock vt]

i've also got 1 funny plug, no.5. its got a little burn mark on the white ceramic bit and keeps happening. (hoping its the injectors)
are all your plugs the same???????

[gherb]

When i unplugged regulator vacuum hose the revs increased due to intake port open to atmosphere, leaning the mixture, and decreased and ran a bit smoother when i plugged the port with my finger. I spose you could muck around with regulator by applying vacuum with vac pump if you have one ( i dont) But as there is high pressure in the line it might damage something else in the fuel system. All my spark plugs are new last week, have changed them twice in the last month, they all looked good.

[wana s' charge stock vt]

for farrrrrrrrkkkkk sake, i got the new injectors in today but now if its been sitting for a while it will turn over for 3-5 sec's befor it starts. but if turn it off and on again it starts straight away. and got a little bit of pinging back again. yay
its like its not building enough pressure for some reason if ya leave it sit for a bit.
changed the fuel filter today too, anyone had the same problem???????????????


really really getting the shits with it now. ,

[wana s' charge stock vt]

yep I have tried spraying water around and no drop in Revs, I tried removing fuel regulator hose from back of plenum to see if there was fuel in the line (indicating leaky diaphragm) but it was dry, it did seem to run a tiny bit smoother when i plugged hole in plenum though. I would like to check fuel pressure at rail to verify correct op of regulator. My radiator cap is mint, no sludgy crap or anything,..

if ya end up getting a new fuel reg try holden first. i'm getting one off them for $68. bursons or global wanted around $160 (for super6 reg anyway)

[maccasparks]

i've also got 1 funny plug, no.5. its got a little burn mark on the white ceramic bit and keeps happening. (hoping its the injectors)
are all your plugs the same???????

I've had this on no.5 plug too - little black build up on white ceramic. Plugs on 1 month old , and have replaced no.5 plug again but still doing it a bit. Motor runs/idles mint! Any ideas??
When I did plugs I also did O2 sensors and just replaced leads today. Done 200,000 km

[gherb]

Well guys after swapping over the coil packs and trying another IAC valve and TPS I took the car into holden. I told them all the work I had done and they rang me 2 hours later saying they had found the prob ......
A stuck EGR valve!!!!!!
The manual says you cant test them so I didnt bother, Got another 1 second hand for $200 NZ. Going to pick the car up after work tonight.
Well done Robertson Holden.

[acarmody]

Huh $200? Guy at Holden quoted me $100 for a genuine new one.

[gherb]

They quoted me $800 for brand new holden EGR valve, managed to get one for $250, I dont really care now cause I,ve got my car back and after everything I have done its running awesome! I forgot what Its suppose to run like. You wouldn't even know the car is running at idle its sooo smooth. I will do a bit of research on this though, thanks for the headsup.