Yaris 1.4 D-4D Losing Power On Motorway

[arizonaicetea]

Had the same problem as first post described.

Details: Yaris D4D, 2006. Went driving, drove through very heavy rain, then after 15 min or so on highway, engine suddenly doesn't give power. It's like the gas pedal was released while actually I pushed the gas to the floor. RPMs dropped, car slowly slowed down. I immediately pulled over, waited 10 minutes, then it drove fine. Then fifteen minutes later, the same happened. There were no problems at low speeds, only at highway speeds (in fifth gear).

So I went to the mechanic, diagnostics didn't show anything. The mechanic added something to the fuel to clean some possible buildups or something. And they replaced the rear brakes one of which was apparently broken. Came out pretty costly but yeah, solved a minor unrelated problem I had.

After picking up the car from the mechanic, went on the highway to test, the power loss happened again, after 5 min going around 120km/h on the highway (sunny, 10-15°C). Before reaching unjammed highway, had to drive at low speeds through slow zones and traffic jams for almost half an hour, so engine had been running for some time before.

On the next day (today) I cleaned the MAF sensor with some contact cleaner, since several posts said power losses could be due to a bad/dirty MAF sensor (and a myriad of other things). Then went test driving. First test was during day (sunny, 10-15°C), drove 20 min on highway speeds without problems. Second test was at night (still dry, 0-5°C), drove 50 min on highway speeds, reached and maintained top speed for a minute, without problems. (in both tests, car had been running at lower speeds for at least 15 minutes before reaching open highway).

So I'm hoping the problem is solved now. Will keep testing and keep you updated and try to figure out with more certainty what exactly the problem is/was. Posting here now with many details because I'm happy and in case someone might still be having problems.

[arizonaicetea]

An update: drove two times two hours on the highway without any problems. So I guess it's fixed now but not sure what did it.

[Damnjan]

On 4/6/2019 at 2:24 AM, arizonaicetea said:

An update: drove two times two hours on the highway without any problems. So I guess it's fixed now but not sure what did it.

Same problem on my Yaris, went few times to official service and thah couldn't solve the problem. Than an local mechanic just clen the MAF (I suppose) and the problem was solved.

 

So I guess that is the same problem. But still confused why Toyota couldn't solve it.

[FROSTYBALLS]

19 minutes ago, Damnjan said:

Same problem on my Yaris

Please update your profile to include the Yaris.

[Ateam]

Hi all

I've just been driving my 2014 petrol 1.4 yaris up the dual cartridge way and it just cut out,.lost power and slowly came to a standstill...frightened the hell out of me due to where I was, right on a bend at peak 70 mph rush hour....

Ran diagnostics and shows no error codes, no lights came on and wont start just ticks over 

Any hints/tips would be great, this post seems very similar issue to what I've got 

[furtula]

So basically the car just died?

All the accessories still work with key in ACC on position?

The car cranks, but does not start?

What diagnostic did you use? 

When the car died, were the electronics still functiong, power steering, lights etc?

What kind of key do you have, physical or smart?

[Kamkhan]

I have an 2008 1.4 diesel and I have exact the same problem. On the motorway the power cuts out but after the car let's out some thick black smoke it drives normal again.