1999 S70 Acceleration Hesitation

s70NA · Post by **s70NA** » 06 Apr 2014, 11:56

So, my 1999 S70 has a new issue. Yesterday I replaced my engine mounts, as such, I disconnected my battery so that I could remove my starter and get to the front hydraulic mount easily. All went well and I reconnected my battery. The car started fine, but I could tell that something was different because the engine idled higher for a few seconds longer before settling into the normal idle. No big deal, backed the car up, shifted into drive and it died. I restarted and drove and noticed a hesitation upon take off, press the gas there was a delay of 1-2 seconds before anything happened. This also happens when trying to accelerate moderately to hard at highway speeds. When the car warms the problem is less but still there and still very noticeable. My ETM is very clean, I've always kept that clean, air filter is new.

I checked codes today and it's showing a P1004, which I can find no reference to for Volvo. Please, any help is appreciated!

EDIT- I forgot to add that I can get the car to die every single time if I'm in park and I rev the engine to 3-4k RPMs and let go.

chrillew · Post by **chrillew** » 07 Apr 2014, 11:21

Have almost the same problem, when engine is cold it hesitates on acceleration on low revs and no boost.

It accelerates then drops in revs, next second it keeps going and then drops in revs again over and over... but my car never stalls. weird problem.

Write here please if u get ur problem solved.

Post by **rmmagow** » 07 Apr 2014, 11:47

I'm not sure if this works with an ETM engine. Disconnect the battery again, clear all codes, leave it disco'd for 15~20 mins. Reconnect the battery, start the engine and just let it idle all the way to full warm and see if that helps. Retraining the idle settings.

s70NA · Post by **s70NA** » 14 Apr 2014, 09:37

OK, I figured out what my problem was. On the drivers side of the intake manifold there are two small nipples that attach to devices, one goes to the bottom of the air box, the other goes to a small sensor mounted right above the radiator. The hose that connects to the sensor above the radiator was broken, I assume this senses airflow/pressure. Anyway, I replaced that hose and all was right again.