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Re: Low boost problem Posted by Bill Homer [Email]  (#3427) [Profile/Gallery]
(more from Bill Homer) on Thu, 14 Jul 2005 07:44:58
In Reply to: Re: Low boost problem, Dan91-9kt, Thu, 14 Jul 2005 05:27:00 Members do not see ads below this line. - Help Keep This Site Online - Signup |
I doubt that you would hear or feel any change from banging on the knock sensor. The BPC is sent two streams of electrical pulses ("pulse trains") which cause the metal "puck" inside to shift position, i.e. more boost (keep wastegate closed) or more dump (open the wastegate). These pulses are sent at a constant frequency, something like 70? Hz (up to a certain RPM value, at which point it changes to a higher constant frequency, something like 90? Hz), but the width of each individual pulse is varied by the ECU. A momentary individual knock will not produce the effect that you are looking for. If both of your BPCs are good electrically, I would doubt that they are both bad - you did take resistance readings across the coils, right?
I would check the bypass valve, also known as the "hooter" valve, especially if you have the old style with part number that does not end in -010.
posted by 129.188.33...
, Thu, 14 Jul 2005 07:44:58 <-- Viewing This Message, Thu, 14 Jul 2005 09:51:02
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