Engine Chuggs while in gear

klynch · Post by **klynch** » 16 Oct 2005, 18:29

i have a 1994 volvo turbo wagon, and have a parculiar problem. While in gear the rpms drop intermittently but does not stall, and, it does not do it all of the time. Some times it idels fine at a light for up to a minuet, but then starts again. Once the gas is applied and the rpms go up, all works fine and no other issues.

TIA

KL

Guest · Post by **Guest** » 16 Oct 2005, 21:59

It almost sounds to me like your A/C compressor is cycling on and off (on drops the rpm and off raises the rpm). I'm not sure just how your car is wired, but in my 1986 740, the A/C compressor runs whenever the three A/C (snowflake) positions or defroster position is selected on the vent controls. Turning the fan control to "O" does not shut off the compressor. The owner's manual states that whenever these four positions are selected and the fan control is turned to "O", the fan will continue at minimum speed and the compressor will continue to run. The only way I can get both the compressor and the fan to shut down completely is to set the vent controls in one the remaining three "non-A/C" positions. Also, when the A/C system is low on charge, the compressor will cycle on and off.

Take a look at your vent controls and verify whether this condition continues when a non-A/C position is selected.