ASV Replacement Time (1987 Brat)

[aba4430]

Folks,

A couple of months ago I wrote about my carb throttle being stuck wide open. I transported my Brat behind our expedition on a U-Haul auto transport from Albany, GA to Chesterfield, VA in late May. I am 100% sure now that it was linked to crude from the plastic silencer that gave out due to a busted ASV on the right side. I searched all the related articles on the site and came across this one:

http://www.usmb.net/repair/index.php?CurrentDirectory=FOLDER_3f29ddceb73856.77194796/&FileType=Article&File=ARTICLE_3f3c62be2ef9f8.91773347.art

So I ordered two pieces of part number SPS377200 from www.worldpartsexpress.com. A separate issue, but excellent customer service from these folks and their prices including shipping is fantastic when compared to others (I will write more separately about my experience with these folks). Well I received one of the two pieces (other one on order) am getting ready to replace it on the 87 Brat. I have a couple of questions as I want to avoid breaking the part and adapting it to the Brat, if I can. As posted in the repair article, the new part has the same bottom and internals, but a different top. The top has a connection for a little tube (vacuum???) and the box also included a section of vacuum tubing. Per the repair article, I can swap the top from the Brat and not use the top piece from the new part and repair the ASV. However:

1. What is the function of the vacuum?? port on the top part. If it just sucks air, I can connect it to one of the unused plugged ports on the air cleaner?

2. If vacuum is pulled out of this port on the new ASV, and since the Brat does not need it, can I just plug this port.

Just trying to keep it intact and not having to disassemble it!

Thanks in advance for the replies.

aba4430

[GeneralDisorder]

1. It functions to shut the valve off on those models equipped with a feedback (computer controlled) carb.

2. No, as your Brat does not have a computer or the solenoid to turn the valve on and off, it's best to just eliminate that part of the valve - otherwise you would need to supply it with constant vacuum for the valve to stay open durring operation.

 

That said, those valves are not necessary - they are a LOT more trouble than they are worth, and just removing them entirely will improve the overall running quality, and eliminate a possible failure later on. If eliminateing them is not possible because you have underhood inspections, undo the pipe from the head to the valve, slip a quarter (yes - $0.25) into the valve body, and thread the pipe back on. This will disable the valve, and leave it in place so the inspection will assume it's still working. They really don't do much, and if the engine is tuned it should still pass a tailpipe sniff - if you still need it to pass for some strange reason, repair them as you planned, still use the quarter, and just remove the quarters when you need to hit the smog shop - otherwise they are just a time bomb waiting to happen all over again.

 

Here in OR, I don't need to smog any of mine, so they are all gone. Ports welded up - never to be seen again.

 

Note - if you swap out to the SPFI from the EA82 you no longer need these valves as the function is provided by the fuel injection computer.....

 

GD

[Uberoo]

the same thing happend on my 84 brat.ruined the carb.so I just got a weber carb and got rid of the ASV alltogether along with numerous vacuum lines that werent needed anymore.Car ran alot better right up until the headgasket blew(un related issue)

[aba4430]

GD and Uberoo, appreciate the responses. Will keep you folks posted. aba4430