I'm pretty sure as you turn the wheel, sitting still in particular, the idle would dip down as the ISC does not compensate because the ECU wouldn't know the power steering is being loaded up. Although I'm assuming it fails in a way that it gives a no pressure signal.
#580/2000 (Long Gone)
#908/1000 Black (Sold)
Posts: 6240 | From: Richland, WA | Member Since: 02/09/03 | IP: (220.127.116.11) |
belize1334 well bread and nobly conceived 1334/2000
posted 05/17/10 04:35 PM
I assume that if the ECU knew the power steering was in use it would raise the rpms preemptively. With it broken you blind-side the ECU by suddenly bogging the engine with the load from the PS pump. Then the rpms rise again as the ECU tries to compensate for the bog (w/o knowing what's causing it). Then when you let off the rpms would rise farther as you remove the load on the engine without telling the ECU what you're doing. Then they stabilize again as the ECU compensates to get rpms under control (still not knowing what's going on).