I have seen the posts and read the volvospeed write-up on the air pump system, but I don't want to replace everything in the system. I had a mechanic replace the SAS valve, air pump and relay about 18 months ago, but the CEL is back on again and I am told it relates to the air pump system again.

I have tried the following things: I removed and inspected the pump and it had no water in it. On a cold engine, I removed the vacuum line at the SAS valve, and I got vacuum. When I reattached the vacuum line to the SAS valve, the valve clicked repeatedly. When I checked the larger diameter hose coming from the pump, I felt no air coming to the valve. Is there a way to hard wire the pump to see if it works? Is there a way to check the relay at the pump bracket to see if it works? Does anyone else have any ideas short of replacing everything again?

Also, I read something here about fuel trim being disabled when the CEL is on. If the pump is only supposed to run for a minute or so, would fuel trim be disabled only at this time - or whenever the car is running? I don't really know what fuel trim is, but it must be significant to merit a mention here.

Finally, Victor Rocha did a fine job on my ABS controller.

Bill

Bill,

Post your codes here. Could be a bad SAS valve again, but might also be a faulty relay, or something else.

Fuel trim is disabled during cold startup, in order to aid the car in getting up to temperature. The air pump system is part of that inasmuchas it helps speed the heating of the catalytic converter during startup, so that the "cat" can take care of emissions related to disabled fuel trim.

In short, the air pump system (PAIR) is part of the emissions control of the car.

BB

Did you get any feedback on this post? I'm trying to learn about what might be going wrong w/ my CEL & EGR system...
--
(92 240 wgn, ex-88 240 wgn)