why do engines pull less vacuum on hot start?
#1
why do engines pull less vacuum on hot start?
I've noticed this on both my friend's FD I've been tuning a lot recently (both have Power FC) and my own FC, both of which had engines with good compression. On a hot start I notice both cars pull about 1 to 1.5" less vacuum according to the mechanical boost gauge (14" versus about 15-15.5 on motors with significant porting). This makes them fall into a different cell in the fuel map. Once the car gets going for a few minutes the vacuum reading returns to normal.
Has anybody else noticed this? I am guessing that engines make less compression when they are heatsoaked, which explains why weak motors are prone to flooding.
Has anybody else noticed this? I am guessing that engines make less compression when they are heatsoaked, which explains why weak motors are prone to flooding.
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trickster
2nd Generation Specific (1986-1992)
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07-01-23 04:40 PM
befarrer
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08-22-15 05:52 PM