Hi all,
I'm on my 3rd pump. The original's bearings finally died as did the replacements. I got another used one and it runs fine (and quiet) but if I don't drive it for several days and it is cold outside the 40A fuse blows. The wiring looks pretty decent. Has this happened to anyone else and it turned out to be the pump?

Personally I'd love to just get rid of the SAI.

Thanks
Chris

 

In theory your pump fuse blows because the in-rush current to the electric motor when it starts exceeds 40A. One band aid is to use a slow-blow fuse of 40A.Do not use a higher amp fuse. Check/replace the relay.
A better approach would be to remove the pump,dismantle it and fit a new bearing. The grease in the used pump bearing is probably dried out. Try to get a replacement bearing(they are generic) that is rated for high temperatures. It will have high temperature grease in it and high temp seals.The incremental cost over a standard bearing is minimal.
You hinted at the best solution -remove the silly SAI and plug the vacuum ports.
There are several issues with this.
1.It would fail the visual part of the Smog Test in some areas.
2.You would need an ROW re-flash to prevent a CEL. The visual is an unlikely issue. There are a few Porsche Indies who will quietly do the ROW re-flash for you.They do not broadcast this because it is not smog-legal. In many Green countries ,'smog pumps' are not used .They are only operated for a few seconds(yes, seconds!) at start up.It is arguable that you'll create more total environmental impact with endless parts replacement/CEL fixes/Smog check failures. There is a chance that a future more sophisticated Smog Check machine may detect the re-flash and fail your car.
This is just general background. Before you proceed you need to find a Rennlist contributor who has a thorough understanding and recent experience of the SAI delete issue(not me unfortunately). Try Search as a start and contact some of the smarter contributors directly ?I am dithering about doing the SAI delete so please let me know what you eventually decide to do.
Here is a helpful article to get you started:
http://blog.rennwerks.com/?p=153

 

This is why I love Rennlist! Thank you for all the info. I was wondering about the slow-blow fuse myself as the pump sounds decent. After having two with bearings that went I know the tell-tale Jet Engine sound. The MAXI fuses I've been getting from Advance Auto are kind of junk. Pep Boys has a much better one that states it is designed to handle a large inrush of current. I'm going to pick one up tonight.

Thanks!
Chris

 

Are you using some variety of aftermarket part? I'm just curious why they seem to keep failing for you.

 

Nope these are factory parts. The first two were bad bearings and I didn't know you could rebuild them. The one I have now is fine but I believe the 40a Maxi fuse had been buying from Advance Auto was junk. The one I just picked up from Pep Boys has much more material and designed as a slow blow for current inrush.
Chris

 

Glad this worked for you.
Please let us know the number on the bearing in the SAI so we can help others with SAI problems in future.
The Chinese fuse problem is serious, here is an example:
http://www.motorsforum.com/gm/wixom-...all-32382-.htm
There is no way of telling if the fuses are grossly under-rated/over-rated visually .So either your wiring gets fried/car burns or the fuse keeps blowing. There is probably a lesson here ?