I’ve recently rebuilt my carb and just about dialed it in. After driving it a while I noticed the fuel consumption is way higher than it’s supposed to be and the car jerks while driving, granted it did that before the rebuild.

I’m gonna replace the fuel lines from the tank to the mechanical fuel pump but I’m wondering, does it also have a sender pump in the tank?

I know the fuel injected ones do but can’t find much info on the carburated models.

Car itself is a 1984 242 DL, B19K with a Solex Cisac Z4 and M45 mt.

Ignition should be out of the equation since I’ve rebuilt the distributor, changed plugs, checked the wiring resistance and changed the coil.

Any tips and tricks on how to fix this and lower the consumption are highly appreciated

 

There's no pump in the tank on a carburetor fuel system. New fuel lines will not solve your problem unless the carb is suffering fuel starvation due to a crimped fuel line or some other unusual blockage.

Most "jerking" problems will be caused by misfires in the ignition system. Sure the fuel mixture may be off - I have never seen a Volvo with carbs after 1971 can't tell you if there is a mixture adjustment. Most carbs (other than SU style) have fixed jets and the idle mixture is the only thing adjustable mixture wise.

 

I have some documentation on the carb and I know there is a mix screw and a separate idle screw. I might as well replace the fuel lines and ignition wires to see if that fixes it

 

Also as a side note, while tuning the carb I noticed that if I turn it any richer it starts running poorly and any leaner and it loses so much power that uphills need to be taken in 2nd gear. It kinda does it now as well but not as much.