Cold idle issues

February 3, 2017

For the last week we have started having an issue with the idle when the car is cold where the revs drop and the car feels like it might stall but doesn't. It only happens when the car is stone cold and only lasts for 1-2 minutes, when the car is warm it starts and idles fine.

Drives fine otherwise.

I was thinking the idle control valve may be the issue, I will attempt to clean that this weekend if it stops raining, I cleaned the throttle body about 6 months ago so doubt it's that dirty already.

Any ideas/ thoughts?

February 3, 2017

I had almost the same problem on a 2001 1.4 VVTi, the only difference was it would put the engine management light on.

I had a brief chance to fault-find before the symptoms went away (until the engine was cold again). The fault was happening for days before I fixed it.

I think I used a can of freezer spray to try to pinpoint the failing part.

This car had a Pierberg throttle body with a Denso idle control valve. The valve was secured by two 5-point(!) Torx-style security fasteners. Removing and thoroughly cleaning the valve made no difference to the fault.

The idle valve was only available as part of the throttle body, which was about £400 from Toyota.

I got one from a breaker for about £12, and replaced just the part with the Toyota label and the shiny Allen bolt showing in the 1st picture.

Since replacement 4 years ago, it has never gone wrong.

Some ingenuity is needed getting the bolts off, the picture shows the new ones.

February 4, 2017

20 hours ago, Gerg said:

I had almost the same problem on a 2001 1.4 VVTi, the only difference was it would put the engine management light on.

I had a brief chance to fault-find before the symptoms went away (until the engine was cold again). The fault was happening for days before I fixed it.

I think I used a can of freezer spray to try to pinpoint the failing part.

This car had a Pierberg throttle body with a Denso idle control valve. The valve was secured by two 5-point(!) Torx-style security fasteners. Removing and thoroughly cleaning the valve made no difference to the fault.

The idle valve was only available as part of the throttle body, which was about £400 from Toyota.

I got one from a breaker for about £12, and replaced just the part with the Toyota label and the shiny Allen bolt showing in the 1st picture.

Since replacement 4 years ago, it has never gone wrong.

Some ingenuity is needed getting the bolts off, the picture shows the new ones.

Thanks for your input.☺

Have been watching a few videos on YouTube and if cleaning in situ doesn't sort it I then I think I might just replace the whole throttle body, can be had for between £30-£70 on eBay.