Hello, I've just bought a 1988 Volvo 780 so I figured I'd join the forum.

It has the v6 b280f engine with some problems starting in hot temperatures (after driving it does not restart). Also when idle the RPM is not consistent and when steady it is probably too high (1000 rpm).

As far as I can tell the starting problem is present in the engine coolant temperature sensor which I just bought a replacement for today. I've gathered that I need to drain the coolant in order to install the part; however, I cannot find the petcock to drain the fluid to a level below the sensor.

Also, does anyone know where the best place is to put jack stands for this vehicle?

 

My guess would be that the car has a bad MAF. If it is the coolant temp sensor, I just replaced one today without draining the coolant system. I just put a pan under it and filled in what came out.

As for jack stands, put them under the frame or the tri plate. If you post a photo of the bottom of the car I can point out points for you.

Welcome to the site.

 

Check the date stamped on your fuel system relay (white relay, left side, second row on fuse/relay board behind ashtray). If it is original or more than ten years old, replace it with new If this isn't your current issue, it may very well be the next one. Symptoms often include hard- or non-starting in heat. Also, I wonder if your idle air control valve might be the problem--erratic idle speed suggests poor air control.

 

Hi guys, thanks for the replies. I ended up replacing the coolant temp. sensor and it now starts every time! I didn't need to drain the coolant, just plugged the hole with my thumb and shoved the part in.

It also seems to be running smoother since I've driven it a bit and gone through about half a tank of gas with some fuel injector cleaner

I love this vehicle! I will take some pictures this weekend. Rust free body with only 161 000 km!