Rough idle and misfire VT

[thepaver]

Hi all
My wife's vt is running rough at idle and is misfiring randomly at idle. Theres a vibration through the car while its sitting there running. We have had new engine mounts put in it, new leads, plugs are gapped, vacuum hoses are all good. The centre muffler has about a 15mm deep dent in it where she has mounted a kerb some time ago not sure if that would make a difference. Have checked purge hose under tb and seems ok. When idling it seems to chug and has started to blow little smoke. Would this indicate valve stem seals?
Its her daily driver so we really need to keep it running but Im out of my league on this thing i think. Checked for fault codes and none are coming up just keeps doing one flash two flash one flash two flash which i think is all good? pls correct me if im wrong

Thanks for your help

[Tw11ga]

A coil pack may have died and therefore the engine is only running on like 4 cylinders. I had similar symptoms and this was the issue. I think my mechanic replaced the coils then discovered it was actually the control module the coils plug into. Try pulling spark leads off while the engine is running if pulling one doesn't make a difference there you have it. Just a suggestion.

[thepaver]

thanks for the advice just checked coils got a pretty nice boot off the first one i pulled lol they are all good. Only really does it on idle and when it is just starting off moving. Once you actually get moving power is good and runs pretty well. Car has 208000kms so not exactly a fresh motor.

[brodster]

Try another air flow meter if you can borrow one as hat can cause that prob

[Commo_Carl]

AFM is pretty common for this in most makes of cars. As for the dent in the exhaust, depending whether its really closing up a majority of the pipe I don't think it would do much. However it is possible to throw sensors off (have seen it before)

Do you have any Air/Fuel controller or adjustment hooked up to your ecu? Have also seen problems arise because of them.

[dazzalenko]

had a similar problem
especially when i booted it
used to misfire and jump bounce
found out i had a crack in the rubber boot from the throttle body to the air bon
also under the phelum chamber theres a hose that runs to the drivers side of the motor (rear) might have come off
hope it helps
cheers

[thepaver]

Thanks heaps for replies. Copping daily ear bashing for not having it fixed yet. There is a small crack in induction pipe which I have fixed. Purge hose is ok. Couldn't find a new pipe so just sealed crack for now. Car is dead standard no mods except lowered. Bought new idle control valve which made it drop back to idle a lot quicker but still same rough idle. Have new Cas to put on and will prob put new balancer on at same time. Thought that might have something to do with it because of vibration at idle. Other than that no idea.

[thepaver]

AFM is pretty common for this in most makes of cars. As for the dent in the exhaust, depending whether its really closing up a majority of the pipe I don't think it would do much. However it is possible to throw sensors off (have seen it before)

Do you have any Air/Fuel controller or adjustment hooked up to your ecu? Have also seen problems arise because of them.

No nothing is different to factory and it has been a brilliant car up to now. It is serviced regular and hasn't cost a cent since 2004 when I bought it other than two batteries in that time. I checked water last night and it took nearly 4 litres?? Isnt leaking on the drive so I am going to have to look into that too. Sump oil doesnt look milky at all but filler cap had milky sludge (not heaps) around it on inside. Is it possible intake manifold might have sprung a leak and thats why its running crappy? Seems to be turning into a nightmare and am in two minds whether to buy a new motor for it and not have to worry about rebuild costs. Crate motor couldn't be much for one I wouldn't have thought.

[fyrbrd]

Have you tried your O rings on your injectors?? i had a similar problem when i got my 2nd VT and my O rings around the injectors were buggered got new ones on fixed the problem jus fine.

[thepaver]

thanks man have been looking at reconditioned set of injectors on ebay and wondering whether to bite the bullet and just get them so i can rule out another possibility. Injectors do tick while its running fairly loud, not sure if thats normal.

[pieces]

Look for the most common easy faults first . As some one else said check the coil Packs . Ive had VR / VS /VX every time I had a misfiring it was a coil pack . You can do a simple test with a meter between the terminals of a coil you should see about 5.5 k OHMS with a meter most of my faults were open circuit tho I had one that measured ok and still misfired .

PS I wouldnt go any where near the end a spark plug lead they give you a fair belt and seeing spark on a lead dosnt mean all is well . If cash is an issue grab some second hand coil packs .

[thepaver]

thanks for the reply
do i have to take the coil packs out to do that or can you do it on the car? Sorry man if its a stupid question but ive had points ignition cars for 17 yrs this is first efi and computer controlled car ive had so it kinda baffles me lol.

[FstStig]

Engine Miss fire = Bad Coil packs and or DFI Module. It's throwing your timing out.

[thepaver]

thanks for your reply.
im going to replace coil packs anyway because i figure they are pretty old. do i have to do the dfi module at the same time?
Just managed to get an error code out of it. code 29 came up. when you bring revs up and hold them it is smoking out the back. nothing major but condensation coming out even mid afternoon and even when engine is warm??

[pieces]

thanks for the reply
do i have to take the coil packs out to do that or can you do it on the car? Sorry man if its a stupid question but ive had points ignition cars for 17 yrs this is first efi and computer controlled car ive had so it kinda baffles me lol.

The test is done in vehicle remove the spark plug leads on one coil .And test across the 2 terminals .

[FstStig]

You don't have to do your DFI module at the same time, although it probably wouldn't kill you to do it as well, to help rule it out. In regards to the black smoke when the motor is warm it does sound like its being caused from your timing being out and it is generally caused by the Coil packs .