Hello,

I just bought my first Volvo, it's a 1984 245. Had to run it on a full tank of gas to get home, I believe that the problem is the tank pump. It ran very smoothly and had plenty of power it cruised happily at 70 all the way. My problem is that is has a an idle that surges every 60 seconds or so at idle. It was misfiring before I bought it, but I replaced the cap, plugs, rotor and wires, which seems to have fixed that. We're going tomorrow to pick up the tank pump and fuel filter and we'll be doing a general cleaning and inspection of the fire trap and vacuum lines ourselves. Any ideas what the problem may be with the idle?

thanks!

 

Your tank pump could be rusty with holes in it and the air that goes in causes this...?

 

The in-tank pump has little to do with idling. Checking all of the vacum hoses is a good start. Also, you probably should clean your throttle body as these can get all gunked up and cause the throttle from completely closing and turning on the idle circuit. During idle, the throttle body should be closed and all air enters the intake through the idle air controller.

Also, you would be good to get a service manual to help you through these procedures. Haynes is ok, a Bentley manual or Volvo green books are better. Some of the Volvo green books can be found at K-Jet.org | Mechanical Fuel Injection Power!