Vacuum gauge questions
#1
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Vacuum gauge questions
Trying to tune my Megasquirt and I found an interesting problem. When I crack the throttle my vacuum gauge increases from 18inHg to 22inHg, then goes up when the throttle opens more. Could be a problem?
#2
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I'm not exactly sure what you mean, but my car idles at about 21inHg Vacuum. If you're saying that the more your throttle is open, the more vacuum it pulls; then there is something wrong.
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Yes I think so,What I mean is the vacuum increases for a second or two from 18-22 then starts going in the right direction the more throttle is given. I am going to confirm with Megasquirt gauge tomorrow. Very strange.
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What does everyone think of my problem in relation to the 3rd paragraph in this article about MAP sensors. I could be on to something as I never noticed this breaking in my engine on factory management the last two weeks...unless I'm completely off base here.
http://www.aa1car.com/library/map_sensors.htm
http://www.aa1car.com/library/map_sensors.htm
#5
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"When conditions change and the vehicle is cruising along under light load, coasting or decelerating, less power is needed from the engine. The throttle is not open very wide or may be closed causing intake vacuum to increase. The MAP sensor senses this and the computer responds by leaning out the fuel mixture to reduce fuel consumption and advances ignition timing to squeeze a little more fuel economy out of the engine."
If that is what you meant, here's my take. If I start my car and it idles, it's pulling about 21inHg. If I am going down a big hill and I'm off the throttle sometimes it'll pull 24inHg.
If that is what you meant, here's my take. If I start my car and it idles, it's pulling about 21inHg. If I am going down a big hill and I'm off the throttle sometimes it'll pull 24inHg.
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Ok so I had a vacuum leak causing 18inHg instead of 22inHg at idle and then, cracking the throttle pulled more vacuum down to 22inHg. Applying more throttle pushed the vacuum up to 0-ish, Still cant figure this out...I need vacuum gauge numbers from all you low compression turbo guys running megasquirt
Last edited by JEMERY; 12-30-2010 at 08:22 PM.
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