Car has seizures when Idling, Drives perfecto??

[R.D]

Hey team, (searched but found nothing just like this)

My B4 Legacy, has developed random shaking when idling. Whether its in gear or in Neutral seems to make no difference. Doesnt not happen on cold starts, only once warm and stopping at lights etc, it will maybe bog down and shake once every 30seconds. Is this a misfire? Whats causing this and how can I conquer this?

Cheers!!

[albaru]

As an experiment, turn off your a/c when you're idling at the traffic lights. See if that removes the shaking.

[nickmcgill]

Mines been doing that for ages, I've done basically everything to try and fix it including changing the voltage on the TPS.

Mines been doing it for about a year or so now tho.

[R.D]

^ what does yours idle at. I feel that my idle speed could be increased. After the shake it sometimes will stay at around 500?

My plan was to increase the idle, but I read that this simple 'adjust the idle screw' is only a thing for older engines, where on modern cars it's not a good idea due to complexity of the ECU system??

[nickmcgill]

It vairies, On a cold start it will normally sit around 1,500 for a good 2 min or so then drop to around 800.

It's normally quite bad though when it's knocking round revs seem to move a bit 100~rpm.

I cleaned out the idle control valve on the TPS and that helped a bit but I was guessing it was just cause my ks are at 230k and it's getting tired. Perhaps not ?

[subieboy]

Tried replacing the Airflow sensor??

[R.D]

^ Wouldn't that be affecting the car when driving tho? Drives fine still

[subieboy]

 R.D said:

^ Wouldn't that be affecting the car when driving tho? Drives fine still

Not always... when they are stuffed they can behave in rather weird and wonderful ways.

Stick a ohm-meter and see what readings you get.

[Guest]

 subieboy said:

Tried replacing the Airflow sensor??

+1 super common for these to run fine when cold, at cruise and under load. But have a massive idle surge when hot

[nickmcgill]

 subieboy said:

Tried replacing the Airflow sensor??

Tried twice, Both times didn't fix the issue. If anyone in chch want's to have a look feel free I'm out of ideas lol

[kiwisurf]

Have you cleaned the throttle body out yet??? Worth a try.

[R.D]

As in the upper engine cleaner? Yeah have done that.

Seemed to come on all of a sudden, not a gradual thing

No engine codes.

[subieboy]

Are you using a POD filter

IF so a few things to check:

Oiled or not

Is it securely fitted (i.e. have you supported it with bracing)

How much oil have you got on the filter...

The BH/BE AFM hates vibration, kills the AFM like the dodo

[R.D]

thanks but na stock airbox still. No modifications to the car at all.

[Guest vf20/21bg5]

Its "Car Parkinson’s disease"......

Car Parkinson's disease is a disorder of the motor that leads to shaking (tremors) and difficulty with idling and car coordination....usually occures with old age. ;D