1999 S70 ETS Light And Sputtering When Idle

[Autry5150]

I have a 1999 Volvo S70 2.4L Naturally Aspirated with a brand new Fuel Filter, Fuel Pump, Fuel Pump Relay and many other little things. Replacing these made the car run perfectly for about two months after it had been sitting for about 3 years but a couple days ago it died at a red light and then started back up again but ever since then when breaking and sitting idle it will start to sputter out and the rpm will drop down to 0 and the kick back up to 1-2 and when it kicks back up black smoke will come out and when revving the engine black sludge came out. A day after that happened the ETS (Electronic Throttle System) light came on and continues to act up when idle like at a red light but runs perfectly fine when driving (like on the highway) any help / insight is very much appreciated. Thank you

[Ozark Lee]

Do you know if your ETM is a white sticker or a yellow sticker? At this point I'm not sure if any of the white sticker versions are still in circulation but if you have one then it is bad by now for sure. The yellow sticker versions act up as well but they tend to last longer.

At the end of the day the throttle module is telling you that it doesn't like the data it is sending or receiving. Most of the time it is due to the throttle position sensors growing dead spots but sometimes you can get by with just cleaning the module. If you try to clean it be careful not to get solvent into the position sensors on the sides. That hastens their demise.

There are retrofit position sensors made by Sacer https://en.sacer.com.cn/products/tps-se ... volvo.html but they aren't cheap. There are You Tube videos that go through the procedure to change them. It requires some decent soldering skills.

The other option is to send the module out to have the sensors changed to the Sacer versions. More expensive than DIY but they are tested and usually are plug and play when you get the module back. XEMODEX is a vendor that will do it for you.

...Lee