yaris 2004 1.4 d4d rough idling at cold starts see video link

Honest John Back Room » Technical matters
View Threaded
Sun 6 Apr 2014 18:15
yaris 2004 1.4 d4d rough idling at cold starts see video link - yaris d4d

hi question regarding a 2004 Toyota Yaris T SPIRIT D4D Turbo Diesel idling issue when first starting the car
if i take the air pipe off egr valve the car idles correctly and revs normal ,if i reconnect it the problem comes back if i take the pipe off the throttle valve in the video the car revs normal, the cars done 37000 genuine miles i have cleaned the Egr nothing of concern it was ok ,i cleaned the mass airflow with proper cleaner no change, is there anything else i can check , air filter all ok , the car when warm runs and ticks over as normal what could be causing this strange problem will an egr valve cause the throttle control valve to operate without touching the throttle in the car .??????????????please see video regarding the problem

video link see problem tinypic.com/r/103syt1/8

anyone know what could be causeing this problem

Edited by yaris d4d on 06/04/2014 at 18:18

Reply | Report as offensive | Link
Thu 9 Jul 2015 10:53
yaris 2004 1.4 d4d rough idling at cold starts see video link - Cloversmate

Hi - Have the exact same problem.

In fact, there are two electrically controlled/connected vacum valves on the front of this engine. Denso branded part. The one on the RHS goes to the EGR, the one on the LHS feeds a vacum-operated valve which connects to what appears to be an idle/air control on the air inlet manifold.

A problem with the left valve will cause the engine to run roughly.

You can stop the problem (as I discovered), by just disconnecting the electrical lead. It has a captive connector so it will require insertion of a flat screwdriver at a single point.

In the longer term, I would recommend replacement of this vacum valve. My local Toyota dealer quoted me over £330 for a replacement valve part so I looked online. Ebay. On my 2005 model, the correct valve part number is 25819-33010 / 139700 - 0790

However, I saw a very similar part - see part number below - which appears to work OK, and only cost £35 inc postage.

JOb Done - Engine now runs sweet and smooth.

Cloversmate

25819-33030 139700-0970

Reply | Report as offensive | Link
Thu 25 Feb 2016 18:17
yaris 2004 1.4 d4d rough idling at cold starts see video link - Datoo

Hi Cloversmate,

I am glad that I came across your reply as the same sympton has developed in my Yaris D4D. I followed your reply however I struggled to remove captive connector. I used 2 flat screwdrivers on each side to release the connector. Any photos would help.

Thanks,

Asif

Reply | Report as offensive | Link
Tue 13 Dec 2022 14:41
yaris 2004 1.4 d4d rough idling at cold starts see video link - varga

Hello, I konow that is very old trade, but have you ever solved your problem? I have problem with cold start in the morning where the temperature is under -5 degrees celsius. It has difficulties to start and when it starts then it is very rough idling until maybe a 1 minute. I haven't check my glow plugs yet (but i do not have some failure showing on dash board). Anyway I will change fuel filter tomorrow, and check glow plugs. Any other suggestion? Mine is Yaris from 2012.

Thanks and regards

Reply | Report as offensive | Link

If you cover no more than 100 miles per day and have easy access to a charging point at home or work, then an EV is ideal for you.

Is an electric car right for me?