Engine rpm hovers around 1300 sometimes

icelandic · Post by **icelandic** » 22 Oct 2009, 17:34

My 1994 850 NA has developed a tendency for idle to stay at 1300 rpms with my foot out of the pedal during decelleration. It happens ramdonly and when it happens i just press the pedal a bit and it immediatelly goes back to 800 rpms. TB is clean as well as the IAC.

What shoud I look for next? No codes, engine runs like a champ.

9394volvo850s · Post by **9394volvo850s** » 22 Oct 2009, 17:42

sounds like it could be in the linkage. check the rod that goes from the throttle cable wheel to the throttle body. it may need a bit of adjusting. its hard to diagnose problems when theres no codes.

xb corp · Post by **xb corp** » 22 Oct 2009, 18:37

guys;
1. sticky accelerator assembly. start with pedal assembly > kick down switch area > cable route (make sure not twisted, clipped) > throttle drum.
2. broken/ leaked vacuum
3. throttle position sensor connector (dirt, oxidization)
4. dirty idle pump.

tassieti · Post by **tassieti** » 22 Oct 2009, 23:30

That happens on my 94 850 T5 aswell sometimes. In my case it is because the clutch gap on my aircon compressor is too large and the computer thinks it is on and therefore raises the rpms to compensate for it but infact it isn't on.

icelandic · Post by **icelandic** » 23 Oct 2009, 09:42

Thanks to allthet replied. I checked linkage this morning the problem was the rod with the two ball joints connecting the throttle cable wheel and the TB. It is actually adjustable (I didn´t now that). I took it out increased the lenght by approximately 1mm and all is ok now. Perhaps wear on the ball joints or on the TB became critical at that particular lenght and it just needed to be adjusted.

Thanks,

Icelandic