I am having a lot of trouble getting my 2000 volvo v70 running smoothly.

Initially it ran rough and misfired, so I replaced all 5 ignition coils and plugs. The car began running smoothly and handled an hour drive on the highway no problem. Shortly after I began to have ETM issue symptoms (limp home mode randomly) so I replaced the MAF sensor. That didn't solve the issue so I ended up buying a XeMODex refurbished ETM and installed it. I started the car up, and drove it 15-20 miles through the city no problems at all.

Just when I thought I solved the problem, the next day I went to drive it down the street and it stalled at a stop sign. From that point on it would only start and run for like 3-4 second then shut down as if the fuel was cut off. If you played with the throttle as it tried to die you could keep it running and eventually after like 60 seconds of babying the throttle you could get it to poorly idle. My first thought was I botched up a vacuum line when doing the ETM switch (as I actually took out and installed the ETM like 2-3 times). I carefully removed the new ETM again, checked all the vacuum lines closely, put a new fiber gasket (instead of the metal gasket), and carefully reassembled everything again.

That puts us where the car currently stands. After reinstalling the etm, the car turns on and after 3-4 seconds begins to surge. It will idle normally for a second or two, the almost shutoff entirely, then go back to idling, over and over and over. It does keep itself running, but barely. For ****s I put in a new fuel filter, made no difference. I initially thought it was maybe the antenna ring for the key, but now the car does actually run - sorta.

Because the car throws no error codes (and hasn't at all through ANY off this) I have no idea where to go from here. I was hoping someone may have some insight. If its beneficial I can take a video of the tach while its running but it doesn't seem very insightful.

 

Have you checked the Crankshaft position sensor and the Camshaft position sensor? If either one are going out, they can cause the car to run poorly and cause no-start conditions.

If you have a digital multimeter, you can unhook the sensors from the harness, wave a wrench in front of them and see the voltage spike as you do so. If there is no change in voltage, you have a bad sensor.

Good luck with your wagon, I know how hard it is not having a reliable vehicle. My wagon is currently down for the count with a mysterious no-start condition as well.

Oh, and as a side note, neither of these sensors have been shown to throw a code when they malfunction.