Hi, I just have to say first that I am so happy there is a forum dedicated to the Volvo 780, we could use all the information that there is. I have an 87′ that has only had two real problems but, they have been plaguing me for over a year. The first is the bad idle. When I start it, no matter if engine is hot or not, it idles very poorly. When it is moving, it seems to be in perfect health. This problem is only when it is staying still- like at a traffic light, the RPM’s fly up and down from 1,000 to 2000. I have replaced the fuel pump and filter, battery, wires and plugs, and the fuel injection relay- nothing has worked. I can’t figure it out and neither can the five mechanics I have taken it to. What am I missing?
The second problem is causing me to fail inspection. When I turn the lights on, nothing works, taillights, headlights, signals, fog lights, absolutely nothing. I can only get them on if I hold the level for the high beams, then everything works. I have replaced the bulb failure sensor and it didn’t help. The previous owner did his handy work on the wiring for the lights with “speaker wire”- or so my mechanic said. I have a feeling it has to do with this but I can’t even begin to understand why in one day the lights would work, then turn off in a sec. How do I trouble shoot for this, I know nothing about electrics. GAH
I love the Volvo 780 and I have spent many hours a day keeping mine looking good and running well. I am just at a dead end and could use some help.
Viva the Volvo 780
-S
