VS - Puff of smoke from the engine?

[dimzi]

Hey,

Long time lurker here; whenever I google search anything about commodores, I always seem to get led to this forum, so its about time I signed up!

I've been having a slight problem with my 3.8 VS...
About 2 months ago, I went to start her up; she struggled, then I heard a 'pop' and she kicked over, then I noticed smoke coming out from the drivers side of the hood. Quickly turned it off and had a look, and didn't notice anything out of the ordinary.
Called my old man to have a look, and it started up without a hitch (typical!).

Then I noticed it started to run a bit rough, like a cylinder wasn't firing; when idling it sounds like its going to conk out, then the computer kicks in and revs it up a bit, then repeat. Engine visibly rocks more than it used to. Fuel economy has definitely decreased; used to get 400 on a tank, now barely get 350 with increased highway use.

Have tested leads (zap!) and spark plugs, all good. Changed the fuel regulator on advice from distant-relative mechanic, no change. Injector cleaner tried, intake throttle cleaned; pretty much anything cheap and easy I've tried, without effect.

Anyone have any ideas?

 

[bandit10]

have you check for error codes .?? if so what did you get?

https://forums.justcommodores.com.au/threads/checking-error-codes-vr-vs-revised.22307

 

[dimzi]

have you check for error codes .?? if so what did you get?

https://forums.justcommodores.com.au/threads/checking-error-codes-vr-vs-revised.22307

Actually did that the other night, got: 12, 12, 12, 12, 12, 12, 12, lol
Was out there for about 10 minutes before I got bored of counting 12's, bit disappointed actually; thought it would have detected a problem of this nature.

 

[The1]

smoke is useually just the rockers leaking oil onto the exhaust manifold, they do that when cold overnight and leaks few drips!

id check the 2 vacumme hoses that run to the vacumme module at the rear of the engine, one runs to the bottom of the air intake on near the butterfly and the other goes to the charcol canister at the front near the radiator.

id also check the iac valve (idle air control valve) it sits in the side of the intake mainfold near the butterfly on the rear side of the engine, just unplug it and pull it out, it's spring loaded so be carefull, but give it a good spray with carby cleaner and if your comfortable enough take the top of the intake manifold plenium off and give it a good spray in the iac hole to clean it out.

 

[Brett_jjj]

If it feels like the engine has a miss and is popping and spluttering under load, it might be one of the coils is stuffed.(they spark ok when idling but break down when under load).You can check them with a multimeter but Ive seen them show ok but still cause problems ,so try to get a coil either second hand or borrow one from a mates car,then try the coil in the 3 places where your coils go.Drive it and see if its any different each time you move it to the next coil.If it turns out it is a coil,id try to replace all 3 at the same time.Try to use genuine holden or MSD or similar.The cheaper ones are a waste of money.

 

[dimzi]

I did clean the IAC valve a while ago on the advice of relative-mechanic, it seemed to help powerwise but didn't solve the problem - will have another look anyways, and will check the vacuum hoses as well.

I remember when it blew a head gasket (~+1 year ago) a coil pack went as well, so that might be a possibility, but would be easy to check seeing as though the issue remains when idling - I checked that the leads were sparking (reason for the 'ouch!') but only on one side, the side that I saw the smoke from. Will check them all this time and have a look at the coils as well.

*fingers crossed* I hope its an easy fix, cause I really don't want to spend too much money on it atm seeing as though I have ceased FT work and have returned to study!

Thanks for your suggestions