Hi,
My 82 928 is idling poorly. It runs okay when I first start it from cold, then the engine starts to surge up to say 2000 RPM for a few seconds, then falls back to 1000 or so for a few seconds, then back up, then back down, over an over. The OX light in the instrument cluster is on. Could this be a vacuum problem? If so, is there a common vacuum leak on my car that I can look for?
Does anyone sell a kit that has all of the replacement vacuum hoses?

Thanx,
Joe

 

Hi Joe,... it,s definately a good idea to replace all the vacuum lines as like my 80 928s they were all brittle and snap like a carrot...,I had similar symptoms to yours, ie erratic idle etc etc,.... sizes I used were 3mm i/d, 4mm i/d and some 9mm i/d,... the stuff that mainly deteriorates is the lines that are covered in a canvass type material.

My car now idles/runs much sweeter,.. and when first done the idle speed dropped a little, which proves there was vacuum leakage with the old vac lines.
Good luck

Ken
90 928s 300bhp
5 Speed

United Kingdom