Polo rough idle on cold start, idle stumble, etc

**s4mmie** · 02-07-2012, 07:32 PM

As the title, when I first start the Polo up in the morning while the SAI pumps still doing its thing if I try to move it out the driveway to shut the gate it misfires, sounds like its on 2/3 cylinders. Even tonight when I pulled out and accelerated it bogged down. I know I should probably wait a minute for it to warm up but I'm wondering if this is pointing to a bigger problem as I also have a stumbling idle as well. Every so often the revs will drop slightly when idling. Has anyone had these kind of problems? Could it be a coil-pack? I'm going to check all the vac lines tomorro...

**flat6** · 02-07-2012, 10:26 PM

Best guess would be coils or spark plugs, have also heard of the fuel pump causing similar issues, how many k's has your car got?

Have never experienced these issues with my polo so def not normal.

**Smead** · 02-07-2012, 10:47 PM

Sounds like coil packs... I'd try them first

**noone** · 02-07-2012, 11:40 PM

Idle is fine, could be injectors, check the spark plugs as well. Have you tried picking up the revs a bit more? I know I can move it easily at idle revs, but if it's cold, could be something.

Maybe the SAI issue is happening to you?

**Jmac** · 03-07-2012, 08:00 AM

Most likely if its only on start up and goes away itll be the SAI for sure. Just had one yesterday that had been to a couple of shops and already had all of this thrown at it, not sure why, plugs would show up more when warm, anyway it was the SAI, it was working kind of but replaced it as it was under a stat warranty and all good.
Cheers
Jmac

**s4mmie** · 03-07-2012, 12:05 PM

Hmm thanks for the feedback guys.
I checked all the vac lines to be sure, nothing I could see.
I pulled the coils and plugs this morning to check for any abnormalities.
A visual check on the coils look fine, no tarnishing, etc.
The spark plugs look to be running a little on the lean side to me. This might be affected by the 10 secs I drove it in the driveway with the SAI pump on.

I'm running BKR6E Iridiums at 29 thou gap at the moment. I had standard BKR7E's in before and there wasn't any difference.
Here's the plugs...

I've ordered some new 2.0 coils and adapters (why not

) and the parts I need for an emissions delete from INA.
Knock both of them on the head hopefully...

Forgot to add that the coils appear to be revision 'C', so fairly early versions from what I've read...

**noone** · 03-07-2012, 01:04 PM

There was a recall on the injectors, I had new ones installed last year by stealership free.

Plugs look normal, I'd get a gap measuring coin (ebay) so you can see they are all a similar gap. I've been running a fairly high gap, never noticed any issues.

If anyone else is getting the electrical plugs from INA, can you please let me know so we can split shipping costs, I just cant get past paying as much for the freight as the parts...

**vwthunder** · 03-07-2012, 01:39 PM

I have played around with the gap a little, and if its wrong, will stuff up your idle

I would not run irdiums, i would rather run normal plugs and change them more often

**vwthunder** · 03-07-2012, 01:40 PM

Originally Posted by noone

If anyone else is getting the electrical plugs from INA, can you please let me know so we can split shipping costs, I just cant get past paying as much for the freight as the parts...

I would be in for some of their stuff too