I was driving to work last week and just before I got to my destination, my car started running a bit rough. Nothing too new, she runs rough once in a while but this was different. I was having a heck of a time troubleshooting the behavior. High RPM she's run fine & low barely at all. I didn't have time during the week to look at it so on Saturday, I cleaned out the garage enough to get my car inside. Having no idea where to start but suspecting the carburetors I took off the air cleaners. SU carburetors work a bit differently than most but I could tell right away that something was wrong here. The right piston was higher than the left in the picture below.
SU Carburetors
The left piston was jammed & stuck in the suction chamber (that bell looking part with the little black cap) and there was nothing I could do to get it freed up. I've heard of these carbs freezing up like this but I really didn't expect it to happen to me. Luckily, I've been hoarding Volvo parts and I happen to have another set of these carbs in a box. I pulled the suction chamber assemblies and replaced them and I'm back on the road.
