I am second owner of 1993 Volvo 960 with 135 K mileage on it. I noticed recently while driving that from time to time the engine (or transmission) will slightly hesitate. Does not change gears or shows RPM going up or down, but feel like for a split of a second is badly starving for a gas. The dashboard works fine and I am not noticing any electrical issues. When the car is in Park the engine works fine. The idle sounds also perfect. No codes displayed. Always starts and never stopped working. I am not sure if that is not only my imagination, but looks like the problem is more visible while going uphill than on a flat road. Any ideas where to start?

 

Is the CEL on?

 

No CEL light on at this moment (and I am driving for at least 2 months), but while ago I had code 241 - EGR Flow too low. Clear the codes while I was doing routine maintenance and the code never show up again

 

If you have no CEL my guess would be that you have a fuel flow problem. Most other issues make the CEL come on.

Try running 91+ octane for the next 2 tanks and see if that makes a difference.

 

Thanks, Will try