Poor idle Vt commodore

[teddybear]

Hi guys , i am at my end trying to work out why , my vt wont idle properly.

I recently had to do the head gasket and had the head shaved ect .

I torqued the heads done exactly to how they said and i put the lifters ect back in exactly where they came out of (so they were not mixed up) I then torqued them and I also torqued the inlet manifold down wiith new manifold seals and I silconed the corners .

I started the car and ran it on idle for 30 min topped up the coolant and bled it ect and after doing this i then dumped the oil and oil filter and replaced with new stuff . But the car still running like **** ! So naturally i replaced the spark plugs and i actually went and got new leads!!!.

The car still running bad. So did a error check and it came up with no problems. ??? All vacum hoses are on and the purge hose is connected to the throttle body !!.


I have combed the car looking for reasons why it would be running this way and cant pin point what it is .

Does anyone have any ideas on where i may have a problem . As the car seems to run ok once its mobile, but i would say it has been better.


Cheers

Ted

 

[accentstencil]

The IAC valve controls the idle so that would be a place to start. A good clean often helps.

 

[vt_lover]

I know it might sound stupid, but are all the leads in the correct order? and are you getting spark on all cylinders? an easy way to check the spark is to get a pair of pliers and GENTLY remove the lead off the plug while idling. see if the motor makes a reaction to this. if it does the plug is working. do this one at a time until all six are checked.

 

[Umai Naa!!]

Clean the throttle body out. Well.

As accentstencil said, also clean out the IAC.

 

[teddybear]

Ok thanks guys , So when cleaning the throttle body out would be wise to undo it and place a new gasket ect !!. ( Is there any documentation on the correct way to do this , for novice ppl) and is there ajustments or any thing that could be the problem ie loose idle scew ??.

Other things I did were:
Take the iac valve and TPS off and clean them with a cloth.
looked for air vacum leaks
changed the spark plugs again with older ones that I know did work (in case of a faulty one)

I did a fault code check and everything is a ok showing code 12
But when the car idles it misses ie that it is sucking air or something and the car shakes a bit like its got a bit of a lumpy cam in it LOLOLOL.

cheers

 

[accentstencil]

Removing the throttle body is straight forward, just undo anything attached to it and undo the nuts holding it on.
To clean it, buy a spray can of carby cleaner or throttle body cleaner and just spray it on (use a lot). It will dissolve most of the crap on there and you can use a toothbrush to help it along. Also clean the IAC valve with the same stuff.
I would replace the throttle body gasket and the O-ring for the IAC valve.

 

[teddybear]

okly cheers !! I will see how it goes thank you!!

 

[VL-VP-VT]

my old VP did the same thing, sounded real lumpy, replaced all the leads and plugs, made no difference, checked all vacuum hoses, all were good. checked for spark as mentioned above, checked the coil packs, all were getting spark. checked the resistance of the coil packs all were in specifications, still couldn't find the problem. took it to holden they replaced one of the three coil packs and for some reason it was all good after that. apparantly the spark wasn't strong enough coming from one of the coils. don't know why the resistances where all in specifications though. just one of those car things hey.
if any one has a car similar to yours borrow a coil pack and try putting it on your car, youll have to put it in all three positions, unless you fluke it first go.

 

[teddybear]

Umm Tried that as well mate . I even went and bought a coil. No good!!. ?? it really could be the igintion module but who knows. I think its off to holden and then they can tell me what it is or does anyone else know where to go on the north side of Brisbane for Commodores?????

They should be able to just by using the tech 2 , as I aint paying Millions of dollars for nothing!!!.

Ted