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Re: Trying to unplug knock sensor cable... Posted by RS [Email] ![]() ![]() ![]() In Reply to: Re: Trying to unplug knock sensor cable..., Aris, Fri, 10 Oct 2003 11:25:45 Members do not see ads below this line. - Help Keep This Site Online - Signup |
A couple of things to keep in mind
- knock sensors sometimes crack and go bad
- When you unplug the knock sensor, the APC box sees an open circuit and drops you to base boost
- Sometimes the knock sensor cable goes bad (often near the connector) and the APC box sees that open circuit like above. If the rubber boot at the connector has split moisture can get in and cause corrosion, too.
If you have a known good knock sensor, you can swap it in and see what happens.
Another thing to look at is cleaning the APC solenoid. It's really a simpleminded thing. A steel slug is the thing that opens and closes the pressure circuit. When the solenoid is energized, the slug is drawn up into the coil, moving it away from the seat, and it opens the valve. When it's de-energized, a spring pushes the slug back down on the seat. The slug gets sticky with oil residue sometimes and doesn't move far enough from the seat. Cleaning it with car cleaner can sometimes make a big boost difference.
posted by 63.148.1...
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