1989 Volvo 240 Wagon – Surging Idle Issue (Need Help)

Tisbo_02

Hey Everyone,

I’m having an issue with my 1989 Volvo 240 wagon where the revs are surging at idle, in neutral, when parked and when driving. The revs will randomly surge to different ranges often, maxing out at around 3,000 RPM. The surging can also make the car cut out when it gets too low. (VIDEO LINKED BELOW)

What’s odd is that when we’re driving, there are moments where everything works perfectly. We can drive around the neighbourhood with no issues, but then, all of a sudden, the surging starts again.

So far, we’ve:

Cleaned the mass airflow meter
Checked for vacuum leaks (none found)
Tested the idle air control valve (it works)
Replaced a fuel trap hose that had a vacuum leak
Cleaned the throttle body

Despite all of this, the surging persists. Has anyone dealt with something similar? Could there be something we’ve overlooked? Any advice would be greatly appreciated!

Thanks in advance.

I've attached the vid below 🙂

volvo-surging-video.mp4

7MB

jamesinc

Someone with a 740 is having a similar issue at the moment, the engine/engine management is the same as your 240 and you should be able to try the same diagnostic processes https://ozvolvo.org/d/30882-lurching-at-idle/