VX with rough idle.... possible causes?

[Lex]

Yes O-ring. Replaced that.
Replaced or switched out everything mentioned above. Supercheap Calibre coil pack swapped position s. (haven't done the module that sits under the coils).
IAC (might be GOSS) coming from Sparesbox, the tps from Repco was Goss. Spark plugs were an unknown brand that were supplied with the blue spark plug ignition leads. I think the brand was Eagle.
But I have swapped one of the original OEM leads through the positions and doesn't seem that is the actual problem.

Still driving the car around and the idle is still getting worse.

Dfi can be the problem?

Can also be the dfi wiring. Can also be plug that goes to the dfi.
Can be a lot of things?

Start with the easy thing first (won't cost anything, til you find a faulty part). Start the car when dark or in the garage. Raise the bonnet. Look at the coils, see any sparking? If not. Take one lead of a spark plug or a coil. Then start engine, idling same or rougher than when all leads on?

You can check dfi plug by taking it of the dfi (7mm socket?).

I think thats enough for now. see how you go?

 

[VT&VX]

Dfi can be the problem?

Can also be the dfi wiring. Can also be plug that goes to the dfi.
Can be a lot of things?

Start with the easy thing first (won't cost anything, til you find a faulty part). Start the car when dark or in the garage. Raise the bonnet. Look at the coils, see any sparking? If not. Take one lead of a spark plug or a coil. Then start engine, idling same or rougher than when all leads on?

You can check dfi plug by taking it of the dfi (7mm socket?).

I think thats enough for now. see how you go?

I forgot to say, after replacing leads, spark plugs and then switching out a coil into various positions, I bought a little spark test device. It is an inline light in an ignition lead.
It shows the spark is there while car is idling.

It didn't reveal an obvious problem with wiring or spark plugs.

So after that I have been focusing on the vacuum hoses, tps and IAC.

I read one of your posts and it mentioned the pintle size difference. So that led me to the IAC409 versus the IAC552.

I am going to remove the TB so I can check the vacuum hose connection when I put the new IAC on.

Yes it could be an intermittent wiring problem, whenever I am checking this or that I start wondering about whether I made something worse by pulling or pushing on the wiring loom.

Too bad these cars need an expensive Diag test dongle.

I should really get Repco to plug in and check it if the next step doesn't get a result.